02 jurnal imj june 2008

INININININDODODODODONNNNNESIESIESIESIESIAAAAAN N N N N MMMMMININGININGININGININGININGJOURNAL

ISSN 0854-9931Volume 11 Number 11, June 2008

The Current Status of Iron Minerals in IndonesiaSiti Rochani, Pramusanto, Sariman and Rezky Iriansyah Anugrah

Test of Removal of Iron Minerals from Kaolin Using HGMSLili Tahli

Magnetic Susceptibilities Distribution and Its Possibly GeologicalSignificance of Submerged Belitung GraniteD. Kusnida, P. Astjario and. B. Nirwana

The Availability of Indonesian Oil Product that is Used in the UpgradedBrown Coal ProcessIwan Rijwan, Bukin Daulay and Gandhi Kurnia Hudaya

Petrographic Analyses of Coal Deposits from Cigudeg and Bojongmanik Areaswith Regard to Their UtilisationBinarko Santoso and Nining Sudini Ningrum

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From the EditorFrom the EditorFrom the EditorFrom the EditorFrom the EditorSpectacularly infrastructural development in the world, particularly in China and India, makesprices of mineral and coal commodities sharply increase, and this causes high demand of thosecommodities. It is predicted that it will happen a trend of struggling those resources in the future.However, this case can positively be supposed as the emerging of huge market opportunity. Theconflict, even war, takes place in the 20th century and probably will continue in the 21st century inAfrica, South America and Asia. This conflict is mostly triggered by the fighting of the mineral andcoal resources that are limited in the reserves. For these reasons, Indonesia should play the role ofutilising its mineral and coal resources, particularly for the prosperity of the people.

The progress on coal and mineral technology in Indonesia indicates promising results that havebeen carried out by a lot of researchers from R&D institutions in collaboration with user industries.When the results are developed, it is expected that those commodities can respond and fulfil theneeds either domestically or internationally. Indonesia has great iron mineral resources in the formsof primary iron ore, iron sand and lateritic iron ore. There is an opportunity to process it by apply-ing an appropriate technology to obtain the improvement of the result. This is a promising solutionto beneficiate the resources for a lot of industries in the country. An effort to reduce iron content inkaolin can be made by applying beneficiation test. The kaolin may become whiter and can reachthe standard quality for paper industry. The result of the experiment shows that the optimum con-dition with a certain flow rate gives the quality of kaolin concentrate with a little iron content. Anappraisal of the marine magnetic anomalies over the Belitung waters provides information on thedistribution of magnetic susceptibility values. The susceptibility distribution analyses reveal a strongcorrelation between magnetic susceptibility and type of granites. The nature of submerged Belitungintrusive is suggested as granitic pluton that is associated with cassiterite minerals. This stronglyindicates that exploration of tin minerals can be carried out in offshore of Belitung island in orderto add its reserve. Indonesian coal has a potential to be a major future energy source due to itshuge resource, low cost of exploitation, good quality and supported by appropriate infrastructure.Unfortunately, more than 65% of the resources are categorised as low rank coal. This type needsto be upgraded prior to utilising and transporting for a long distance. One of the upgrading pro-cesses is UBC (upgraded brown coal). Therefore, the coal can be used optimally. Geological set-ting of the West Java region has a main role to characterise the coal deposits, especially due to thedepositional environment and stratigraphic aspect. According to the petrographic characteristics,the coals are suitable for fuel of direct combustion for the small-scale industries that are present inthe surrounding areas. The coals are expected to be able economically to cope with the demand ofthose industries.

The progress and development of the improving technology conducted by the researchers is ex-pected to improve the collaboration between R&D and industries, particularly in self fulfilling thecommodities in which some of them are imported from overseas, especially from China. Thus, thiscan reduce dependence of the commodities.

The Editor

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1The Current Status of Iron Minerals in Indonesia, Siti Rochani, et. al.

THE CURRENT STATUS OF IRON MINERALSIN INDONESIA

Siti Rochani, Pramusanto, Sariman and Rezky Iriansyah AnugrahR&D Centre for Mineral and Coal Technology

Jalan Jenderal Sudirman 623, ph. 022-6030483, fax. 022-6003373, Bandung 40211email : [email protected], [email protected]

[email protected], [email protected]

Received : 24 October 2007, first revision : 06 February 2008, second revision : 26 May 2008,accepted : June 2008

ABSTRACT

Indonesia has great iron mineral resources, comprising primary iron ore (17 %), iron sand (8 %) andlateritic iron ore (75 %). Nowadays, Indonesia’s primary iron (hematite, magnetite) has not been em-powered yet, due to the scattered area of the resources location. Meanwhile, national iron sand iscommonly used for cement industries and its potency has not supported national steel industries yetbecause of low iron content (45-48 %). However there is an opportunity to be processed by usingAusmelt process technology. At present, lateritic iron ore is being used as coal liquefaction catalystin the form of limonite, but hydrometallurgy would be a promising solution to beneficiate lateritic ironore for steel industries.

Keywords: primary iron ore, iron sand, lateritic iron ore. potency, resources, reserves.

1. INTRODUCTION

Indonesia has great iron mineral resources, com-prising primary iron ore (17 %), iron sand (8 %)and lateritic iron ore (75 %). The recent publishedreport or writing is not adequate to inform the latestiron minerals empowerment (reserves, location,processing) and anticipated actions of iron miner-als beneficiation. Therefore, this report is proposedto give further information regarding current andfuture condition of iron minerals beneficiation.Based on secondary data collected, the analyzestates that Indonesia should optimize the primaryiron ore potency although it is scattered at amountof regions because dependences on imported ironore must be eliminated. Having 362,564,042 tonsof primary iron ore deposits, it can be predictedthat exploitation will operate in 52 years.

2. METHOD

Report was taken from the amount of secondarydata, such as government institutions report, maga-

zine; private and government-owned company website; and scientific handbook or literature. Basedon the data collected, the next step is arrangingand analyzing the data to convey the mindset ofIndonesia current iron minerals potency and sug-gest the future scientific action to process ironminerals more useful.

In constructing the analyzes, we use linear correla-tion, chart and graphic to make all variables moreclose.

3. RESULTS AND DISCUSSION

3.1. Iron Minerals

Iron ore is an iron mineral substance when heatedat high temperature in the presence of a reduc-tant, it yields metallic iron (Fe). The most impor-tant iron minerals are magnetite (Fe3O4), hematite(Fe2O3), and limonite (FeOOH). Meanwhile, otheriron minerals such as siderite (FeCO3) and pyrite(FeS2) are not common to process as metallic ironsource. Figure 1 visualized various iron minerals.

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2 INDONESIAN MINING JOURNAL Vol. 11 No. 11, June 2008 : 1 - 17

3.2. Iron Application

Iron is the most used of all the metals, which com-prising 95% of all the metal tonnage producedworldwide. Its combination of low cost and highstrength make it indispensable, especially in ap-plications like automobiles, the hulls of large ships,and structural components for buildings.

Steel is the best known alloy of iron. Some formsof iron metals include (Pramusanto, 2006):

- Pig iron has 4.0 – 5.0% carbon and containsvarious amounts of contaminants such assulfur, silicon and phosphorus. It is only sig-nificance as an intermediate steps on the pro-duction way from iron ore to cast iron and steel.

- Cast iron contains 2.0 – 4.0% carbon, 1.0 –6.0% silicon, and small amounts of manga-nese. Contaminants present in pig iron thatnegatively affect the material properties, suchas sulfur and phosphorus, have been reducedto an acceptable level. It has a melting pointin the range of 1147 –1197 °C, which is lower

than the two main components, and makes itthe first product to be melted when carbon andiron are heated together. Its mechanical pro-perties are vary greatly, depend upon the formif carbon takes in the alloy. ‘White’ cast ironscontain carbon in the form of cementite, oriron carbide. This hard-brittle compound domi-nates the mechanical properties of white castirons, rendering them hard, but unresisting toshock. The broken surface of a white cast ironis full of fine facets of the broken carbide, avery pale, silvery, shiny material. In grey iron,the carbon is free as fine flakes of graphite,and also, renders the material brittle due tothe stress-raising nature of the sharp edgedflakes of graphite. A newer variant of grey iron,referred to as ductile iron is specially treatedwith trace amounts of magnesium to alter theshape of graphite to sheroids, or nodules,vastly increasing the toughness and strengthof the material.

- Carbon steel contains 0.4 - 1.5% of carbon,with small amounts of manganese, sulfur,phosphorus, and silicon.

- Wrought iron contains less than 0.2% carbon.It is a tough, malleable product, not as fusibleas pig iron. It has a very small amount of car-bon, a few tenths of a percent. If honed to anedge, it loses quickly. Wrought iron is char-acterized, especially in old samples, by thepresence of fine ‘stringers’ or filaments of slagentrapped in the metal. Wrought iron does notrust quickly when used outdoors. It has largelybeen replaced by mild steel for “wrought iron”gates and blacksmithing. Mild steel does nothave the same corrosion resistance but ischeaper and more widely available.

- Alloy steels contain varying amounts of car-bon as well as other metals, such as chro-mium, vanadium, molybdenum, nickel, tung-sten. They are used for structural purposes.Recent developments in ferrous metallurgyhave produced a growing range of micro alloysteels, also termed ‘HSLA’ or high-strength,low alloy steels, containing tiny additions suchas titanium to produce high strengths and of-ten spectacular toughness at minimal cost.

- Iron (III) oxides are used in the production ofmagnetic storage media in computers. They

Figure 1. Various kinds of iron minerals

Hematite (Fe O )2 3

Magnetite (Fe O )3 4

Limonite (FeOOH)

Pyrite (FeSO )2

Siderite (FeCO )3

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are often mixed with other compounds, andretain their magnetic properties in solution.

3.3. Indonesia Iron Minerals, Potency,Resources and Characteristic

The amount of Indonesia iron ore resources reachesup to 76 million tons, which is relatively low com-pared to world iron resources and potency whichare recorded as 800 billion tons and 150 billiontons, respectively. In addition, China has iron re-sources as much as 240 million tons. About 90 %of world iron resources comes from iron deposit,called cherty banded iron formation. The sedimentphysically appears as a thin to moderate layercontaining iron oxides, carbonates and silicatesmaterial with chert or jasper. The deposit genesisis related to sedimentation process with under seavolcanism at the era of Pre-Cambrian. The depositformed is found in the area of geological physi-ographic craton. The economical value of depositin Banded Iron Formation is in the range of 25 -35% Fe. Geological survey shows that Indonesiais in magmatic arc leading to the absence ofBanded Iron Formation type. The Indonesian iron

potency is shown in Figure 2.

Iron ore resources and deposits in Indonesia, canbe grouped as iron sand, lateritic iron ore and pri-mary iron ore (Ministry of Industry of the Republicof Indonesia, 2007). The data can be seen onTables 1, 2, and 3.

Figure 3 shows the total amount of each type ofiron minerals summarized from Tables 1, 2, and 3.

However, there are also differences in number com-paring to version of iron mineral resources and re-serves (Setiawan, et.al., 2004;Tambang Megazine,2007), that can be seen in Table 4 and Table 5.

Primary iron ore is found spread out in the area ofSouth Kalimantan, West Kalimantan, Belitung,Nanggroe Aceh Darussalam, Lampung, and Papua.Lateritic iron ore is mostly found at SouthKalimantan, South-East Sulawesi, and NorthMaluku. Iron sand is found, spread out at SouthJava seashore, scattered from Sukabumi toCianjur, Tasikmalaya, Cilacap, Purworejo andended at Lumajang.

Figure 2. Map of iron minerals potential in Indonesia (Directorate of Mineral ResourcesInventory, 2004)

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Table 2. The main lateritic iron deposits in Indonesia

FeRank Province Location Ore (ton) Metal Content Remarks

(%)

1 South Kota Baru 485,219,700 229,088,807 39 - 55 -Kalimantan (Batulicin)

2 South Luwu (Nuha) 371,500,000 182,035,000 49 -Sulawesi

3 West Irian Raja Ampat 287,198,000 94,408,206.02 30 – 43.95 -Jaya (West Waigeo)

4 North Central 203,380,000 62,125,050 - saprolite &Maluku Halmahera limonite

(Mada,Patani Gebe,South Obi)

Table 1. The main iron sand deposits in Indonesia

Rank Province Location Ore (ton) MetalFe

RemarksContent(%)

1 East Nusa Ende 57,134,358 8,570,153.70 15 Titanium isTenggara (Nangapanda) gangue mineral

2 D.I. Kulonprogo, 36,193,173 20,895,397.07 50.7 - 59 -Yogyakarta Bantul

3 North Bolaang 31,400,000 18,208,860 57.99 9.85 % TiO2Sulawesi Mongondow

4 West Java Sukabumi 16,463,154 8,102,028.18 57 -(Ciemas,Jampang Kulon)

5 West Java Cianjur, 7,369,151.69 4,232,103.81 57.43 12.73 TiO2(Sindangbarang,Cidaun)

6 Bengkulu South 3,231,063 1,492,562.95 61.50 coastalBengkulu sediment

that containtitanium

7 Nanggroe Banda Aceh 2,897,114 1,593,412.70 55 sandAceh sedimentDarussalam in the form

of magnetite &ilmenite

8 South Takalar (South 2,865,000 1,146,000 40 coastalSulawesi Galesong) sediment

9 West Java Tasikmalaya 2,357,390 1,323,203.01 57 -(Cipatujah,Karangnunggal)

10 Bengkulu North Bengkulu 1,000,000 350,000 35 Fe2O3(South Muko-Muko)

TOTAL 160,910,403.7 65,913,721.42

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Table 2. Continues ...


(%)5 Southeast Kendari 167,030,930 46,285,565.95 - saprolite &

Sulawesi (Lasolo) limonite6 Papua Jayapura (West 19,310,000 8,457,780 30- 43.95 -

Waigeo)7 Papua Jayapura 17,920,000 5,786,000 17.9 – 45.1 saprolite &

(Senggi) limonite whichthe content ofNi, Co are1.06 – 1.65 %,0.05 – 0.13respectively

8 Papua Jayapura (East 3,503,000 1,124,463 32.1 -Sentani)

9 Lampung East Lampung 2,415,437 421,460.88 43 max -10 Southeast Konawe 1,500,000 735,000 40 -

Sulawesi (Asera)TOTAL 1,558,977,067 630,467,333.4

Table 3. The main primary iron ore deposits in Indonesia


(%)1 West Ketapang, 280,000,000 159,600,000 40- 75 iron oxide

Kalimantan Kendawangan2 West Pasaman 25,590,594 - Unknown -

Sumatera3 East Kutai 18,000,000 9,900,000 56 -

Kalimantan4 North North 17,500,000 5,250,000 30 hematite

Sulawesi Minahasa5 Lampung South Lampung 5,625,000 3,220,312,50 55.05 – 59.47 -

(Sukarame)6 South Balangan 5,126,400 3,140,386.56 54 – 62.66 -

Kalimantan (Awayan)7 Lampung South Lampung 5,060,500 3,035,641 43 - 66 -

(Tanjung Bintang)8 South Tanah Laut 2,478,200 1,444,970.28 40 - 70 iron oxide;

Kalimantan (Palaihari) Cr & Nirecorded atsome places

9 South Musi Rawas 1,600,000 1,131,840 70.74 iron oxideSumatera

10 West Solok 1,583,348 938,450.36 59.27 magnetite,Sumatera hematite in

associationwith Cu

TOTAL 362,564,042 187,661,601

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Table 5. Iron ore potency in Indonesia

Iron ore type Resources (ton) Reserves (ton)ore metal ore metal

Primary iron ore 76.147.311 35.432.196 - -Lateritic iron ore 1.151.369.714 502.317.988 215.160.000 8.193.580Iron sand 89.632.359 45.040.808 28.417.600 15.063.748

Source: NSDM, Directorate of Mineral Resources Inventory, 2003

lateritic iron ore; 1,558,977,067

tons (75%)

iron sand; 160,910,404 tons

(8%)primary iron ore;

362,564,042 tons (17%)

Figure 3. Iron minerals availability inIndonesia (modified from theMinistry of Industry of the Repub-lic of Indonesia, 2007)

Table 4. Iron ore potency and resources in Indonesia

Iron ore type Location Deposits Fe(%)(thousand ton)

Primary iron ore South Kalimantan 11,675,000 43.30 – 66.04(high Fe content, West Kalimantan 1,000,000 55.00suitable for lump ore) Belitung 7,400,000 62.25

Lampung 5,243,000 42.50 – 63.50West Sumatera 1,600,000 -Sub Total 25,478,000

Lateritic iron ore South Kalimantan 565,233,000 38.00 – 59.00(containing Ni Central Sulawesi 375,200,000 -and Cr) Papua (Irian) 123,410,000 -

Sub Total 1,058,600,000Iron sand West Java 3.097.000 38,00 – 58,32(utilized as cement Central Java 86.267.000 59,00raw material, Yogyakarta 30.668.000 59,00containing titanium East Java 15.979.000 51,29 – 51,51

Sub Total 163.311.000Total 1.247.389.000

Source: Directorate of Mineral Resources, Bandung, 2004

3.3.1. Iron Sand Characteristic

Generally, Indonesian iron sand contains high ti-tanium oxide (TiO2), which is undesirable to theexisting iron making process. Titanium as a ganguemineral has an effect on weakening the steelstrength, and corrosion problem to the furnace wall.However, titanium can be separated during smelt-ing as titanium slag to produce steel. Nowadays,titanium minerals are identified as rutile,leukoksine, and ilmenite. Since magnetite andtitanomagnetite are available in iron sand, it canbe eliminated apart from silica and alumina, usingtheir ferromagnetism characteristics.

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Generally, the iron content can reach up to 58%Fe, but TiO2 content is approximately 12%. Be-ing processed as a raw material in iron-steel in-dustries as research did, titanomagnetite-con-tained iron sand became favorable in such of in-dustries. In addition, titanomagnetite contained ironsand would be prospective economically since itproduces ferrotitanium and the high-priced titaniumwhite powder as by product. International tradingrequires iron sand mineral containing ilmenite 34-40% TiO2 and 98 % TiO2-contained rutile. Ilmenite andrutile are used in pigment industry. Meanwhile,titanium itself is used in military aircraft industry.

3.3.2. Lateritic Iron Ore Characteristic

Lateritic iron deposit was formed by chemical pro-cess through ultra base rock weathering process.Yet, the existing sediment has not contributed tocommercial steel industries. The amount ofIndonesia’s lateritic iron ore potency is 1,151,369,714tons, and resource is 215,160,000 tons (Setiawan,et.al., 2004).

Nowadays, lateritic iron ore is known as nickelmine’s iron cap. This type of iron mineral has lowiron content; consequently it has not been utilizedyet as raw material for steel industries. Regardingiron scarce resulted from China high demand ofresources, PT Krakatau Steel has to search localraw material, which is droved to collaborate withPT. Antam and PT. Sebuku Alam cooperating inlateritic iron mining. This collaboration proposesto process iron as nickel processing’s by prod-uct. Lateritic nickel resources potency and reservesof PT. Antam Tbk. are approximately 240 milliontons and 21.6 million tons respectively as shownin Table 6 (Annual Antam Report, 2003).

3.3.3. Primary Iron Ore Characteristic

This type of iron ore is well-known as primary irondeposit; a result of metamorphoses contact withintrusion rocks. Indonesia’s primary iron ore po-tency is about 76 million tons. However, it has notbeen utilized yet, leads to import raw materialdependence (Setiawan, et.al., 2004).

Table 6. Antam’ s reserves & resources, December 2001

Location Reserves Resourcesm wmt Ni % m wmt Ni %

Saprolite :Pomalaa 2.21 2.34 0.87 2.37Gebe 3.14 2.27 2.91 2.60Halmahera-Buli 22.72 2.47 96.68 2.40Gee 4.36 2.25 - -Obi - - 6.11 2.37Bahubulu - - 19.33 2.50Total Saprolite 32.43 2.42 125.27 2.40

Limonite:Pomalaa - - - -Gebe 3.54 1.47 4.18 1.68Halmahera-Buli 15.15 1.45 122.27 1.40Gee 2.28 1.51 - -Obi - - 25.25 1.51Bahubulu - - 58.50 1.50Total Limonite 20.97 1.46 210.20 1.40

Gag Island (JV–BHP-B) - - 240.0(dmt) 1.36Weda Bay (JV-Strand) - - 204.00 1.37

Antam’s Nickel Tenements as per October 2002:

Antam (KP) JV(CoW) Total

16 2 18152,116 ha 133,636 ha 285,752 ha

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3.4. The Prospects of Indonesia IronMinerals

3.4.1 Primary Iron Ore

Since primary iron ore contains metallic iron insignificant amount, it is ready to process in steelindustries which consume almost 98% of total ironore produced.

Raw material for steel making is still imported dueto some reasons:1. Iron sand is not suitable for existing blast fur-

nace process, but it has an opportunity to beprocessed by New Zealand (Ausmelt process),or by direct melting process.

2. High potential lateritic iron ore can be dividedinto two groups: lump ore and fines/clay ore;its utilization is still ongoing research eventhough its exploitation has already started.

3. Primary iron ore has been beneficiated usingblast furnace process (Lampung small blastfurnace), however the potential and resourceare low.

Iron ore is the source of primary iron for the world’siron and steel industries. It is therefore essentialfor the production of steel, which in turn is essen-tial to maintain a strong industrial base. Iron ore ismined in about 50 countries. The seven largest ofthese producing countries account for about three-quarters of total world production. Australia andBrazil together dominate the world’s iron ore exports,each having about one-third of world total exports.

In order to increase the beneficiation of iron oreresources, formerly in the first year of its indepen-dence, Indonesian government planned to developiron and steel industries in collaboration with for-eign countries such as West Germany, Russia(Soviet Union), UNIDO. Team works had beenformed comprising of government institution, re-search and development institutes, and universi-ties to do research in iron ore utilization.

The utilization of iron in Indonesia can be describedfrom the iron consumption per capita which is lowerthan other developing countries. Indonesia’s steelconsumption is about 26 kg per capita (http://members.bumn.go.id/ptkrakatausteel/news.html?news_id=16870, 2007).

Since the current Indonesia steel industries statedthat the ability of steel industrial production is stilldepend on imported iron ore, the potency of ironminerals has to be developed. This leads to de-velop local raw material, forbid exported high gradeiron ore, set up technology suitable for the localresources, and replace imported raw material forsteel making by PT Krakatau Steel. PT. KrakatauSteel’s long term business plan in supply rawmaterial is shown at Figure 4.

According to Setiawan et.al. (2004), national crudesteel capacity is 6.5 million tons per year whichrequires 8 million tons per year of raw materials,including steel scrap and sponge iron. The pro-duction of sponge iron has capacity of 2.3 milliontons per year.

Figure 4. PT. Krakatau Steel long term business plan (material planning)

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If it is assumed that steel scrap takes 10 % insteel making’s raw material and steelmaking in-dustries are running at full capacity, it can be cal-culated that sponge iron requirement will be 5.85million tons per year (90% x 6.5 mill. tons/year).Thus, the sponge iron shortage for crude steelmaking will be 3.55 million tons per year.

To meet national crude steel capacity (6.5 mill.tons/year) and national sponge iron productioncapacity (2.3 mill. tons/year) that needs 4.5 mil-lion tons of primary iron ore (hematite or magne-tite) (Setiawan, et.al., 2004), so the amount of pri-mary iron ore that should be supplied to cover thesponge iron shortage will be 6.94 million tons peryear. By using the data given by the Ministry ofIndustry, the exploitation activities can be esti-mated for 52 years (362,564,042 tons/6,940,000tons per year).

Indonesia lies at rank 37 of major steel producingcountries in 2005 and 2006 (http://www.worldsteel.org/?action=story pages&id=23&subId=195,2007). It gives a signal that the ironmineral resources potency has not been empow-ered yet. The position of each country is shown inTable 7.

The condition of world’s steel supply and demandgives Indonesia an opportunity to vivid and improvenational steel industries, because the major steelproducing countries are also tremendous steelconsuming countries, as depicted in Figures 5 and6. (http://www.worldsteel.org/?action= storypages&id=23&subId=199, 2007).

The national steel production is seemed to beunsatisfactory because Indonesia still lacks ofsteel products in the market, thus affecting thesupply and demand condition. This condition isshown in Figure 7 (http://www.wartaekonomi.com/indikator.asp?aid=7211 &cid=25,2007).

To forecast the future prospect of steel industriesbusiness, all preceding data and economic indi-cators should be considered such as inflation,average economic growth, etc.

With the inflation assumption of 6.0 - 7.5 in 2006,the economic growth 5.8 %, steel productiongrowth 5 % and steel consumption rate 6 %, ahypothetical prediction of future national steel in-dustries’ business can be presented in Table 8and Figure 8.

Table 7. Major steel-producing countries,2005 and 2006

Country2006 2005

rank mmt rank mmt

China 1 422.7 1 355.8Japan 2 116.2 2 112.5United States 3 98.6 3 94.9Russia 4 70.8 4 66.1South Korea 5 48.5 5 47.8Germany 6 47.2 6 44.5India 7 44.0 7 40.9Ukraine 8 40.9 8 38.6Italy 9 31.6 10 29.3Brazil 10 30.9 9 31.6Turkey 11 23.3 11 21.0Taiwan, China 12 20.2 13 18.9France 13 19.9 12 19.5Spain 14 18.4 14 17.8Mexico 15 16.3 15 16.2Canada 16 15.4 16 15.3United Kingdom 17 13.9 17 13.2Belgium 18 11.6 18 10.4Poland 19 10.0 21 8.3Iran 20 9.8 20 9.4South Africa 21 9.7 19 9.5Australia 22 7.9 22 7.8Austria 23 7.1 23 7.0Czech Republic 24 6.9 26 6.2Netherlands 25 6.4 24 6.9Romania 26 6.3 25 6.3Egypt 27 6.0 28 5.6Argentina 28 5.5 29 5.4Sweden 29 5.5 27 5.7Malaysia 30 5.5 30 5.3Thailand 31 5.4 31 5.2Slovakia 32 5.1 34 4.5Finland 33 5.1 33 4.7Venezuela 34 4.9 32 4.9Kazakhstan 35 4.2 35 4.5Saudi Arabia 36 4.0 36 4.2Indonesia 37 3.8 37 3.7Luxembourg 38 2.8 39 2.2Greece 39 2.4 38 2.3Byelorussia 40 2.3 40 2.0Bulgaria 41 2.1 41 2.0Hungary 42 2.1 42 2.0Others 23.3 21.9

World 1,244.2 1,141.9

Source: International Iron and Steel Institute

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In addition, based on Indonesia crude steel ca-pacity ( 6.5 million tons per year), the future usedcapacity can be predicted, taken from the steelproduction per year divided by national crude steelcapacity. As shown in Figure 9.

Figure 9. shows that in 2020, the used capacity ofnational crude steel production would approxi-mately reach the utilized capacity of national crudesteel production. The assumption is based on theconstant capacity of national crude steel produc-tion, and no vigorous investment or expansionson national steel industries in the next 18 years.

Developing steel industries, new factory or addingcapacity in the future depends on many aspectsincluding resources, availability of the energy, fa-cilities, man power, and policy. Resources wouldrelate to technology which is suitable to ore types.The waste will be an important concern since itwould be constructed close to public domain. Thesupporting facilities play an important role, suchas transportation, energy, waste, etc. In addition,iron ore business is still attractive since the riskof the business is quite low and earning beforeinterests and taxes (EBIT) is quite high relative tothe others as shown in Figure 10.

However, the national primary iron ore reserveshave not been processed intensively, because theresources are available in scattered area amongthe land of Indonesia (Tambang Magazine, 2007).

3.4.2 Iron Sand

Recently, iron sand in Indonesia is used for ce-ment industries. In 1999, it reached 544,000 tonsand finally decreased to 245,409 tons in 2003(Table 9). The decreasing volume is likely as animpact of copper slag substitution, i.e. Gresikcopper smelter’s by product which acquired theirconcentrates from PT. Freeport and PT. NewmontNusa Tenggara.

Cilacap iron sand had been mined since 1971 andexported to Japan until 1978. This leads to its lowerresources.

The plan to explore iron sand in Yogyakarta wasbegun in 1971 by PT Aneka Tambang in collabo-ration with Directorate of Geology. The study hadbeen accomplished by Davy McKee to produceiron and steel, similar to technology to processiron sand in New Zealand. In 1981, a team workhad been formed to study in preparing pellet from

China; 30.9%

European Union; 17.1%NAFTA;

14.5%

Other Asia; 14.0%

Other Europe; 3.0%CIS; 4.7%

Japan; 6.7%

Others; 9.0%

Figure 6. The composition of steelconsumed by countries, 2006

Figure 7. Indonesia steel production andconsumption (modified fromwww.wartaekonomi.com)

NAFTA; 10.5%

Others; 7.2%

Japan; 9.3%

CIS; 9.6%

Other Asia; 10.5%

European Union; 15.9%

China; 34.0%Other

Europe; 2.9%

Figure 5. The composition of steel pro-duced by major steel producercountries, 2006

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Table 8. Future prediction of Indonesia steel (ton)

Year Production Consumption Steel Sponge Iron Steel Scrap Primary IronShortage Requirement Requirement Ore Requirement

2001 2,160,000 3,250,000 1,090,000 2,392,615 265,846 4,681,204.012002 2,270,000 3,560,000 1,290,000 2,514,462 279,385 4,919,598.662003 2,040,000 3,180,000 1,140,000 2,259,692 251,077 4,421,137.122004 2,410,000 4,200,000 1,790,000 2,669,538 296,615 5,223,010.032005 3,120,000 4,300,000 1,180,000 3,456,000 384,000 6,761,739.132006 3,276,000 4,558,00 1,282,000 3,628,800 403,200 7,099,826.092007 3,439,800 4,831,480 1,391,680 3,810,240 423,360 7,454,817.392008 3,611,790 5,121,369 1,509,579 4,000,752 444,528 7,827,558.262009 3,792,380 5,428,651 1,636,271 4,200,790 466,754 8,218,936.172010 3,981,998 5,754,370 1,772,372 4,410,829 490,092 8,629,882.982011 4,181,098 6,099,632 1,918,534 4,631,371 514,597 9,061,377.132012 4,390,153 6,465,610 2,075,457 4,862,939 540,327 9,514,445.992013 4,609,661 6,853,547 2,243,886 5,106,086 567,343 9,990,168.292014 4,840,144 7,264,760 2,424,615 5,361,390 595,710 10,489,676.702015 5,082,151 7,700,645 2,618,494 5,629,460 625,496 11,014,160.542016 5,336,259 8,162,684 2,826,425 5,910,933 656,770 11,564,868.562017 5,603,072 8,652,445 3,049,373 6,206,479 689,609 12,143,111.992018 5,883,225 9,171,592 3,288,366 6,516,803 724,089 12,750,267.592019 6,177,387 9,721,887 3,544,500 6,842,644 760,294 13,387,780.972020 6,486,256 10,305,200 3,818,944 7,184,776 798,308 14,057,170.022021 6,810,569 10,923,512 4,112,944 7,544,015 838,224 14,760,028.522022 7,151,097 11,578,923 4,427,826 7,921,215 880,135 15,498,029.952023 7,508,652 12,273,658 4,765,006 8,317,276 924,142 16,272,931.442024 7,884,085 13,010,078 5,125,993 8,733,140 970,349 17,086,578.022025 8,278,289 13,790,683 5,512,394 9,169,797 1,018,866 17,940,906.92

2,000,0004,000,0006,000,0008,000,000

10,000,00012,000,00014,000,00016,000,000

18,000,00020,000,000

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production consumption steel shortage

sponge iron requirement steel scrap requirement primary iron ore requirement

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Figure 8. Prediction of future Indonesian steel industries future prediction

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33.2334.92

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48.0050.4052.9255.5758.34

61.2664.3267.5470.92

74.4678.1982.10

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Figure 9. Prediction of national steel industries used capacity

Figure 10. EBIT margin (%) vs risk (annual price votality) forsome energy and mineral industries

iron concentrate to use as raw material for PTKrakatau Steel.

In 1991, a feasibility study of Kutoarjo iron sandhad been accomplished, collaboration with Aus-

tralia using Ausmelt Technology. For small scaleindustries, it is expected that iron minerals couldbe processed to yield up to 300,000 tons of pigiron per year from 600,0000 tons of iron sand con-centrate.

Table 9. Sale and production of iron sand (ton)

1999 2000 2001 2002 2003

Production 584,428 489,126 469,377 378,587 245,409Sales 496,202 403,099 439,326 340,459 108,555

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Table 10. Estimation of Cement Productionand Iron Sand Consumption

Year Cement Iron

Production SandConsumption

2007 37,000,000 1,110,0002008 39,960,000 1,198,8002009 43,156,800 1,294,7042010 46,609,344 1,398,2802011 50,338,092 1,510,1432012 54,365,139 1,630,9542013 58,714,350 1,761,4302014 63,411,498 1,902,3452015 68,484,418 2,054,5332016 73,963,171 2,218,8952017 79,880,225 2,396,4072018 86,270,643 2,588,1192019 93,172,294 2,795,1692020 100,626,078 3,018,7822021 108,676,164 3,260,2852022 117,370,257 3,521,1082023 126,759,878 3,802,7962024 136,900,668 4,107,0202025 147,852,721 4,435,582

By assuming the annual growth of cement pro-duction is 8 % (optimistic vision), and iron sandconsumption is 3 %, by ignoring the effect of cop-per slag substitution then the projection of ironsand consumption for cement industries is shownTable 10, Figure 11 and 12.

Based on the prediction, it seemed that the ironsand utilization in cement industries is very low,so it is more profitable to be used by iron sand-

steel making industries. However, the iron con-tent in iron sand is low (45 - 48 %) and needsupgrading (63 % minimum) to meet the require-ment for iron-steel making industries (Setiawan,et.al., 2004). This problem can be solved by theapplication of direct reduction smelter process ofNZ-Steel.

3.4.3. Lateritic Iron Ore

Lateritic iron ore (as limonite) is known as nickelmines over layer or overburden. This type of ironmineral has low iron content; consequently it hasnot been utilized yet as raw material for steel in-dustries. However, in the future development plan,due to the escalating nickel price in the globalmarket, both of PT. INCO and PT. Antam Tbk willimplement hydrometallurgy process for the limo-nite ore which is lower cost in energy as well ascapable to treat lower content of nickel in the ore.In addition, limonite is seemed to be high in po-tency since it can be used for coal liquefactioncatalyst.

The limonite is mined about 10 million tons perannum as an overburden of the nickel ore. It con-tains 40 – 50 wt% of moisture but the contentdoes not change even in the dry season or therainy season (Agency for the Assessment andApplication of Technology, 2002).

Soroako limonite is classified at PT. INCO as fol-lows:1. Medium grade limonite (MGL): nickel up to

1.6 % and iron over 30 %.2. High grade limonite (HGL): nickel up to 1.6 %

and iron over 45 %.3. Overburden (OB): nickel up to 1.6 % and iron

up to 30 %

Figure 11. Projection of national cementproduction in Indonesia

Figure 12. Projection of national iron sandconsumption for cement indus-tries in Indonesia

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These limonite have 1 wt% of nickel, and it wasfound that Soroako limonite have superior cata-lytic activity than other limonite found in Australia.Figure 13 gives a sketch of limonite layers onnickel deposit in Soroako, South Sulawesi, theother hand Table 11 shows the characteristics ofthe Soroako limonite catalyst.

Catalytic activity of iron compounds, such as py-rite, limonite, laterite, red mud, and iron sand, havebeen studied for a long time (Pratt, et al., 1982)and all of them have been used in many coal liq-uefaction process. Recent studies showed thatlimonite from Soroako Indonesia exhibits superiorin catalytic activity and are likely candidate as asuitable catalyst (Kaneko, et.al., 2002).

However, limonite is also as a potential source ofnickel and steel industries. As a consequenceother iron based compounds should be taken intoaccount, for example iron sand and red mud. It isknown that, iron sand is used in cement industry.Only red mud has not been utilized properly. Un-fortunately, in terms of catalytic activity red mudis the lowest compared to other iron compounds,leading to lower oil yield. Therefore it is importantto develop a new method in order to improve cata-lytic activity of red mud. PT Antam is constructingbauxite processing plant with capacity of 300,000tons, and about 300,000 ton red mud would beyielded as by product.

According to coal liquefaction commercializationroad map, initiated by Research and DevelopmentCentre for Mineral and Coal Technology (tekMIRA),the limonite resources requirement can be seenat Figure 14.

The potencies of Indonesia lateritic iron ore arenot merely rely on limonite availability but also onother types of lateritic iron ore such as saprolite,pyrite, and peridotite.

Research and Development Centre for Mineral andCoal Technology (tekMIRA) has finished their re-search on the possibility of improving the iron con-tent and eliminating the impurities of Pomalaa lat-eritic iron ore. The final result was restricted tothe impurities content (SiO2, Al2O3) which werestill high (above 3 %) (Aziz, et.al., 2006). Lateriticiron ore has been processed by PT. Antam Tbk inthe form of saprolite and limonite as shown in Fig-ure 15 (PT. Antam Annual Report in 2004).

It is predicted that up to 2025, the limonite re-quirement for coal liquefaction can not be compa-rable to the need of iron mineral as raw materialfor steel industry (Figure 16). In addition, the com-petitive of limonite uses in the future is suggestedby the nickel production since limonite presentswith saprolite.

Figure 13. Limonite layers on nickel deposit in Soroako, South Sulawesi

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Tabel 11. Metal Composition of Soroako Limonite Catalyst

Metal composition (wt% dry) Activity (wt% daf)*Limonite Total Fe Si Al Ni Co Cr Oil yield ∆ H2

SprpakoHGL 45.4 0.60 7.08 0.88 0.02 1.38 47.2 4.7MGL 45.5 0.78 5.95 1.33 0.09 1.16 49.7 4.9OB 41.4 1.68 6.06 1.65 0.08 1.45 43.9 4.3Yandi Yellow 55.6 2.32 1.41 <0.01 <0.01 42.8 4.8

* Liquefaction of Banko coal: 12MPa H2, 450°C, 2h, cart, 1 wt% daf, S/Fe=2.0

Figure 14. The projection of Indonesia limonite consumption for coalliquefaction

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Figure 15. Sales and production of ferronickel and saprolite nickel ore, PT. Antam Tbk, 2004

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4. CONCLUSION

1. Indonesia has great iron mineral resources,comprising primary iron ore, 17 %, iron sand,8 %, and lateritic iron ore, 75 %

2. Current condit ion of iron mineralsbeneficiations are directed to:a. cement industries, using iron sand as raw

material.b. coal liquefaction project, using lateritic iron

ore, especially limonite as catalyst.

In the future, the limonite will not be used asraw material for steel industries. Nickel indus-tries would have possibly improved limoniteas nickel source which in turn, produce ironoxide as their by product (so far, iron oxidehas not been researched as coal liquefactioncatalyst intensively).

Meanwhile, primary iron ore (hematite, mag-netite) have not been empowered yet, due tothe scattered area of the resources locations.

In addition, there is a constraint in empower-ing national iron low iron content (45 – 48 %),whereas the iron content requirement for iron-steel making industries prerequisite is 63 %minimum.

3. To improve national iron mineral resources,subsequent research on adding value to na-tional lateritic iron ore reserves is still neededto support national iron-steel industries moreprofitable and promising as well as coal lique-faction industry.

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Figure 16. Prediction of iron minerals consumption

5. SUGGESTION

Indonesia should optimize the primary iron orepotency although it is scattered at amount of re-gions because dependences on imported iron oremust be eliminated. Having 362,564,042 tons ofprimary iron ore deposits, it can be predicted thatexploitation will operate in 52 years.

Research on coal liquefaction catalyst should bedone immediately related to the use of red mud(bauxite processing’s by product at Tayan, WestKalimantan), and iron oxide (residue of limonitebased-nickel extraction) through hydrometallurgi-cal process. Since iron oxide residues are asso-ciated with waste, it will be disposed to the seaby nickel industries.

REFERENCES

Agency for The Assessment and Application ofTechnology, New Energy and Industrial Tech-nology Development Organization, 2002. Fea-sibility Study on Direct Liquefaction of BankoCoal in Indonesia.

Anonymous, 2007. Konsumsi Baja Nasional BakalNaik Tahun Depan, http://members.bumn.go.id/ptkrakatausteel/news.html?news_id=16870,accessed on September 18, 2007.

Anonymous, Major Steel-Producing Countriesh t tp : / /www.wor lds tee l .o rg /?ac t i on=storypages&id=23&subId=195, accessed onSeptember 17, 2007.

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Anonymous, Steel Production and Consumption:Geographic Distribution, 2006. http://www.worldsteel.org/?action= storypages&id=23&subId=199, accessed on September 17,2007.

Anonymous, Industri Baja: Defisit Mengancam,h t t p : / / w w w . w a r t a e k o n o m i . c o m /indikator.asp?aid=7211&cid=25, 2007. ac-cessed on September 18, 2007.

Azis, M., Pramusanto, Nuryadi, S., Yuhelda, D.,Dessy, A., Soma, S., 2006. Pengolahan Min-eral Besi Laterit, Pomalaa, Bandung: Researchand Development Centre for Mineral and CoalTechnology.

Kaneko T., et.al. 2002. “Highly Active LimoniteCatalysts for Direct Coal Liquefaction”, Fuel81, 1541-1549.

Ministry of Industry of the Republic of IndonesiaDirectorate of Metal Industri Directorate Gen-eral of Metal, Machine, Textile, and Common,

2007. Focus Group Discussion:Pengembangan Industri Baja Hulu BerbasisSumber Daya Mineral.

Pramusanto, 2006. Mewujudkan Industri Besi danBaja dengan Mengutamakan Bahan BakuLokal, Orasi Pengukuhan Profesor Riset,Bandung: Puslitbang Teknologi Mineral danBatubara, ISBN: 979-8641-59-2.

Pratt, K.,C. and Christoverson, V., 1982. Hydro-genation of a model hydrogen-donor systemusing activated red mud catalyst, Fuel 61, 460.

Setiawan, B., Bambang Pardianto, Dwi NugrohoSunuhadi, 2004. Mineral dan Batubara:Peluang Pemanfaatan Bijih Besi di Indonesia,Mining & Energy Vol. 2.

Tambang Magazine, 2007. April Edition, MerahPutih Mengerek Pasar.

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TEST OF REMOVAL OF IRON MINERALS FROMKAOLIN USING HGMS

Lili TahliR&D Centre for Mineral and Coal Technology

Jalan Jenderal Sudirman 623, ph. 022-6030483, fax. 022-6003373, Bandung 40211

Received : 29 August 2007, first revision : 07 May 2008, second revision : 24 June 2008,accepted : June 2008

ABSTRACT

Kaolin from Nagreg contains iron mineral particles approximately 0.58 % Fe that cause a grey color ofthe material . An effort to reduce iron content can be made by applying beneficiation test, usingHGMS (High Gradient Magnetic Separator), so the kaolin may become white color and can reach thestandard quality for paper industries.

A HGMS beneficiation test was conducted at magnetic field strength of 5,000 Gauss. The experi-ments were carried out using variable flow rates of 1, 1.5, 2, 2.5, 3 and 3.5 liter per minute and slurrydensity of 2.5, 5, 7.5, 10, 12.5 and 15 % solid.

The results of experiments show that the optimum condition with flow rate of 2.5 liters/minute gave thequality of kaolin concentrate with iron content of 0.29 %Fe.

Keywords: kaolin, iron, HGMS, beneficiation, magnetic separation

1. INTRODUCTION

Kaolin is an industrial earth material used as fillerand whitener in paper industries, and also is usedas based material for cosmetic industries. In ce-ramic industries, kaolin is used for refinement thesurface of ceramic, and in electronics industrieskaolin is used as an insulator material.

In Indonesia, kaolin deposit spreads in Sumatera,Java, Borneo, Celebes and West side of NusaTenggara. In West Java, Kaolin presents among otherin Sukabumi, Tasikmalaya and Nagreg (Figure 1).Kaolin Nagreg contains iron of 0.58% Fe, causeda grey color to the kaolin. In order to improve thequality of kaolin for paper industries, the iron con-tent should be removed. The specification of ironcontent in kaolin for paper industries must be nearzero (Kogel 2006).

Kaolin deposit in earth performs as clay minerals.Its genesis was due to transportation and sedi-ment processes in long times to perform the fine

structure deposit of clay mineral, with specificmineral compositions.Kaolin minerals have chemi-cal composition of Al2Si2O5(OH)4 that consists ofseveral elements to perform its structure(Wikipedia, 2007) . Kaolin has many kind of qual-ity, depend on the size of fine fraction performsand the chemical elements content.

The type of kaolin considered in ceramic and pa-per industries should have low iron content.Theexistence of iron in kaolin causes grey to pinkcolor of kaolin. The paper industries require kaolinwith iron content as low as possible to give a whitecolor product.

Kaolin has an ultra fine particle size less than 400mesh. The specific characteristics of fine size andsticky mud of kaolin,make it possible to be usedas a filler materials in paper and presents goodquality of paper product kaolin is also used as abasic element for ceramic industries and cosmetic,which presents good quality and well performs ofskin surface (smooth and soft).

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19Test of Removal of Iron Minerals from Kaolin using HGMS ... Lili Tahli

In general, kaolin with less white color is due to highcontent of iron minerals filling its structure. Thereare some kinds of minerals like pyrite, limonite,chalcopyrite, forming as a very thin film coating atthe surface of kaolin (Lawver and Hopstok,1985;Wikipedia 2007). Separation process of iron par-ticle minerals using decantation process or othergravitational processes were not working suffi-ciently, because the size of iron materials are veryfine, caused static electrical force on particles,and tend to stick each others. Another possiblebeneficiation process to separate the iron particlesis by using a HGMS (High Gradient MagneticSeparator) appliance. The principle operation ofHGMS is a combination process between decan-tation and magnetic separation.

The aim of this laboratory work is to test the pos-sibility of reducing iron content in kaolin as low aspossible by using HGMS appliance.

2. METHODS

2.1. Separation Method

Kaolin of Nagreg containts 0,5% Fe. In generalminerals content of iron particle can be pulled outby magnetic field with a certain magnetic strengthto yield very low iron element as pollutant.

The beneficiation test of kaolin was conductedusing HGMS appliance. Separation process wasoperated at magnetic field of 5,000 Gauss at dif-ferent feed rates and slurry densities to get anoptimum result of separation.

In a preliminary work, kaolin was roughly purifiedby decantation method to eliminate quartz andother coarse particles from kaolin. The gravitationalmethod based on the different specific gravity withthe contaminant that is quartz and other coarse

KABUPATEN PURWAKARTA

KABUPATEN SUBANG

KABUPATEN SUMEDANG

KABUPATEN GARUT

KABUPATEN GARUT

KABUPATEN CIANJUR

KABUPATEN CIANJUR

KOTA BANDUNG

ke Purwakarta

CikalongwetanCipeundeuy

Cirata

CipatatPadalarang

Rajamandala

CisaruaLembang

Cimahi

Maribaya

Cinunuk

Dayeuhkolot

Cililin

BatujajarSaguling

SindangkertaSoreang

Banjaran

Ciparay

Majalaya Cijapati

Nagreg

Cicalengka

ke CirebonCileunyi

Rancaekek

Cikancung

ke G

arut

ke Tasik

Ibun

Pacet

Kertasari

Pangalengan

Gambung

Pasirjambu

S. Cileunca

S. Patenggang

Ciwidey

Gununghalu

Rongga

Figure 1. The location of Kaolin Deposit in Nagreg, Kabupaten Bandung

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particles have higher level of specific gravity com-pared to kaolin. To observe the HGMS separationresults, the iron contants in the feed and productwere analyzed.

Iron mineral in kaolin presents by weathering pro-cess of main rocks. There are some kinds of ironminerals of pyrite, limonite and chalcopyrite, thatfound in an ultra fine particles and difficult to sepa-rate because sticky each other in slurry. To sepa-rate those particles, it should be made in the formof slurry at certain density by adding more waterand using continuous stirrer, so each particle min-eral become disperse easily in the form of singlefree particles in water. The slurry was flew downthrough the cell of “canister” by magnetic force.The iron particle can be pulled out from kaolin andtrapped on induction lattices canister to allow theclean kaolin flows down as concentrated kaolin.

The flowsheet of kaolin beneficiation test is shownin Figure 2:

flow rate. The stream flows down passing through“canister” having diameter of 3½ inch with volumeof 866 cm3. The magnetic field intensity at “canis-ter” was 5,000 Gauss. The HGMS equipment canbe seen in Figure 3.

RAW MATERIALS OF KAOLIN

SIEVE AND CHEMICAL ANALYSIS

FINAL CONCENTRATE

DECANTATION

SEPARATION WITH HGMS

CHEMICAL ANALYSIS OF RESULTS

Figure 2. The flow work of present kaolinbeneficiation tests

2.2. Equipment

The HGMS equipment used has strength of mag-netic field on “canister”. The equipment has a coni-cal tube at the topside. Kaolin was stirred withwater in a certain slurry density, with a certain

3. EXPERIMENTAL RESULT

3.1. Raw Material Analysis

Observation of raw material of kaolin was takenby using sizing and chemical analysis. Sieve analy-sis was conducted to observe the size composi-tion of raw material whether larger or smaller than400 mesh. The fraction size smaller than 400 meshwas used as feed in to HGMS. Chemical analysiswas conducted to observe the iron content of bothfraction size. The results are shown in Table 1.

The iron grade of fraction -400 mesh obtained fromsieve analysis was used as basic data for recov-ery calculation.

3.2. Decantation

Decantation test was conducted to the kaolin rawmaterial prior to be processed with HGMS. First,kaolin was mixed with water using continuous stir-rer. The kaolin slurry was then poured through asieve of 400 mesh in opening size, to get fractionsize of -400 mesh. The weight of fraction size +400mesh was measured and calculated. For furtherexperiments, the slurry of fraction size of -400 mesh

Figure 3. HGMS (High Gradient MagneticSeparator) equipment

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3.3. HGMS Experimentation

Beneficiation test using HGMS was conducted withvariable flow rates of 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5liter per minute, and slurry density of 2.5, 5, 7.5,10, 12.5 and 15 % solid.

Feed of kaolin having size of -400 mesh mixedwith water in a certain volume. The slurry densitywas set in fixed value of 10% solid, while feed ratewas varied. The results can be seen in Table 3.

Table 4 shows the beneficiation test results withvariable slurry density. While the flow rate wastaken in fixed value of 2.5 L/min.

Table 1. Size Analysis 400 mesh and Chemical Analysis

NO SIZE WEIGHT Fe GRADE Fe(mesh) (gram) (%) (%) DISTRIBUTION

1 + 400 50.10 10.02 0.13 1.30 Reject2 - 400 449.90 89.98 0.63 56.69 use as feed HGMS

TOTAL 500.00 100.00 0.58 57.99

Table 2. Fraction Size of Decantation tests

NO FRACTION WEIGHTSIZE (mesh) (%)

1 + 400 10.052 - 400 89.95 (calculated)

TOTAL 100.00

was used as raw material for HGMS. To get ap-propriate slurry density needed for experiments,the quantity of water was calculated and added.The result of decantation is shown in Table 2.

Table 4. Result of Experiments (Slurry Density Variation)

Slurry Feed Kaolin MagneticNO density Concentrate Material

(% solid) (gram) (% Fe) (gram) (% Fe) (gram) (% Fe)

1 2.5 250 0.63 207.77 0.25 42.23 2.502 5 250 0.63 207.83 0.26 42.17 2.463 7.5 250 0.63 209.84 0.27 41.65 2.424 10 250 0.63 210.76 0.36 39.24 2.085 12.5 250 0.63 216.04 0.48 33.96 1.586 15 250 0.63 223.26 0.62 26.74 0.71

Table 3. Result of Experiments (Flow Rate Variation)

Feeding Feed Kaolin MagneticNO Flow Rate Concentrate Material

(l/minute) (gram) (% Fe) (gram) (% Fe) (gram) (% Fe)

1 1.00 250 0.63 208.62 0.24 41.38 2.592 1.50 250 0.63 208.68 0.25 41.32 2.553 2.00 250 0.63 208.75 0.28 41.25 2.404 2.50 250 0.63 208.93 0.29 41.07 2.365 3.00 250 0.63 210.76 0.52 39.24 1.226 3.50 250 0.63 215.84 0.67 34.16 0.38

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4. DISCUSION

4.1 Raw Material

The results of sieve and chemical analysis of ka-olin as shown in Tables 1 indicates that only asmall part (10.02%) of raw material had fractionsize of +400 mesh to be rejected. Another partwas fine size of -400 mesh, that was 89.98%.However, this fine material contained higher partof iron grade (0.63%), designating the kaolin be-comes grey color, so it should be removed to givewhite color.

4.2. Decantation

To abtain raw material of kaolin smaller than 400mesh, it should be mixed with water using me-chanical stirrer and then applying decantationtests. The kaolin slurry was then screened usingsieve of 400 mesh. The fraction size of +400 meshwas weighed. The rest fraction of -400 mesh wascalculated, to measure the quantity of water to beadded as needed by HGMS experiment. There isno significant different in weight fraction of -400mesh between size analysis and decantation, thatwas 10.02% and 10.05% respectively.

4.3. HGMS Experiment with Different FlowRate

The results of experiment using HGMS with mag-netic intensity of 5,000 Gauss, flow rates of 1.0,1.5, 2.0, 2.5, 3.0 and 3.5 L/min, were presented inTable 3, and graphically illustrated in Figure 4.

Figure 4 shows that increasing flow rate yieldedhigher iron content of kaolin concentrate. In theearly experiments, with flow rate of 1 to 2.5 L/min,the increasing flow rate gave a small effect to iron inkaolin concentrate, 0.24 to 0.29 % Fe. The graphic

line was nearly flat, and the iron content only in-creased 0.05%, while the flow rate increased 2.5times. However, with more increasing flow rate upto 3.5 L/min caused more increasing iron contentin kaolin concentrate up to 0.52 and 0.67% Fe.The higher flow rate caused more iron far-off dis-tance of “canister”, and flows together with kaolin,therefore the iron content in kaolin concentrateincreases. From Figure 4, it indicates that theability of HGMS to resist the iron content is onlyup to the flow rate of 2.5 L/min. So, the optimumvalue of flow rate is 2.5 L/min. Similar results arealso found by Fontes (1992), using different flow-ing of suspension, during HGMS process. At theslower flow velocity, almost all the clays are re-tained in the canister, so, the iron content in ka-olin concentrate become lower than on the highvelocity. Nevertheless, it is evidence that the lowerflow rate , the lower iron content in kaolin. The opti-mum value of flow rate of 2.5 liters/minute is decidedbased on the capacity of raw materials processed.

4.4. HGMS Experiment with Different SlurryDensity

The experiment with variable slurry density (2.5,5, 7.5, 10, 12.5 and 15 % solid) was operated withmagnetic intensity of 5,000 Gauss. The flow ratewas taken in fix value of 2.5 L/min. The resultscan be seen in Table 4, and graphically illustratedin Figure 5:

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1

1 1.5 2 2.5 3 3.5 Flow rate (l/minute)

Kaolin concentrate Trend line %

Fe

Figure 4. Effect of flow rate to kaolinconcentrate

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

2.5 5 7.5 10 12.5 15 Solid (%)

(%Fe

)

Kaolin concentrate

Trend line

Figure 5. Effect of slurry density to kaolinconcentrate

In Figure 5 it can be seen the influence of slurrydensity to the iron content of kaolin concentrate.In the beginning of experiments, with slurry den-sity of 2.5, 5.0 and 7.5 % solid, the increasingslurry density only gave a small effect on increas-ing iron in kaolin concentrate, those were 0.25,0.26 and 0.27 % Fe. However, increasing slurry

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density up to 10 % solid caused increasing ironcontent in kaolin concentrate up to 0.36 % Fe.The highest density up to 15 % solid, presentsthe highest iron content in kaolin concentrate upto 0.62 % solid. It indicates that the ability ofHGMS to trap iron was optimum at applied den-sity of 7.5 % solid. The higher slurry density causedthe more iron unable to catch by “canister”, andpassing through to kaolin concentrate, so kaolinconcentrate can not reduce the iron content.Fontes(1992) also found that at low slurry den-sity, the iron particles retained easier on canister,exhibited a good separation and yielding a goodquality of kaolin concentrate. It is recommendedto use low slurry density during HGMS process.

5. CONCLUSION

– Result of sieve and chemical analysis for ka-olin raw material indicates that kaolin fractionof - 400 mesh counted 89.98 % weight andthe iron content of 0.63 % Fe.

– Result of beneficiation tests with variable offlow rate indicates that the optimum value was2.5 L/min, in which the iron content of kaolinconcentrate reached 0.29 % Fe.

– Result of testing with variable slurry densitygave the optimum value of 7.5 % solid, in whichthe iron content of kaolin concentrate was re-duced to reach 0.27% Fe.

– The iron mineral content in kaolin concentratehas not met the iron grade required by paperindustry.

ACKNOWLEDGMENT

Many thanks pointing to all friends in processing,metallurgy and chemical laboratories who hadassisted during the test works throughout samplepreparations and setting the equipments. Specialthanks are also presenting to all research col-leagues which have giving many advise and sug-gestions.

REFERENCES

Fontes, M.P.F., 1992. Iron Oxide-Clay MineralAssociation in Brazilian Oxisols: A MagneticSeparation Study, Clays and Clay Minerals,Vol.40, No.2, p.175-179.

Kogel, J.E. (ed), 2006. Industrial Minerals andRocks, SME, American Institute of Mining,Metallurgical and Petroleum Engineers Inc,New York, pp.335-394.

Lawver, J.E. and Hopstock, D.M., 1985. Electro-static and Magnetic Separation, sme mineralprocessing handbook, Norman L. Weiss (ChiefEditor).

Wikipedia, 2007. Clay minerals, the free encyclope-dia, http://en.wilkipedia.org/wiki/Clay minerals

Wikipedia, 2006. High Gradient Magnetic Separa-tors, HGMS-HGMF, Metso Minerals (Sala) AB,SE-733 25 SALA , Sweden.www.metsominerals.com

Wikipedia 2007. Kaolinite, the free encyclopedia,http://en.wilkipedia.org/wiki/Kaolinite

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MAGNETIC SUSCEPTIBILITIES DISTRIBUTION ANDITS POSSIBLY GEOLOGICAL SIGNIFICANCE OF

SUBMERGED BELITUNG GRANITE

Dida Kusnida, P. Astjario and B. NirwanaMarine Geological Institute of Indonesia

Jalan Dr. Djundjunan 236, Bandung-41074 - Indonesiae-mail: [email protected]

Received : 29 January 2008, first revision : 02 May 2008, second revision : 20 May 2008,accepted : June 2008

ABSTRACT

An appraisal of the marine magnetic anomalies over the Belitung water provides information on thedistribution of the magnetic susceptibility values. The 0.001 to 0.003 cgs unit contour values charac-terize the zone of submerged Belitung granite coincides with the zone of less than 50 nT total mag-netic anomaly contour value. Susceptibilities distribution analyses reveal a strong correlation betweenmagnetic susceptibility and type of granites. The nature of submerged Belitung intrusive is suggestedto be granitic pluton of biotite-granite that is associated with cassiterite minerals.

Keywords: total magnetic anomaly, magnetic susceptibility, granite, Belitung, pluton

1. INTRODUCTION

Tin source in Indonesia is part of the South EastAsia Tin Belt that is the richest tin belt in the world.It extends from South China, Thailand, Myanmar,and Malaysia to Indonesia. Tin is formed as pri-mary deposits within granite and at the contactarea within metamorphic rocks that are usuallyassociated with tourmaline and tin quartz vein.According to Pamungkas (2006), two types of clas-sic veins have been mined in Bangka-Belitung Is-lands. Those are fissure veins and bedding veinsin which they are genetically derived from graniteintrusion of the Upper Triassic (± 222 M years ago).

To delineate petrographic and geochemical varia-tions of granitic plutons, previous authors (Tarlingand Hrouda, 1993; Ishihara et al., 2000) have usedmagnetic susceptibility measurements as the tool.Magnetic susceptibility of rocks is determined bytheir bulk chemistry and magnetic mineralogy, inwhich the bulk magnetic susceptibility is possiblycarried by ferromagnesian silicates (Gleizes et al.,

1993), or on ferromagnetic granites in which sus-ceptibility is carried mainly by magnetite (Ferré etal., 1999). Magnetic susceptibility measurementshave also been widely used as lithologic indicatorin granitic rocks or in the broad discriminationbetween paramagnetic (ilmenite-type granites) andferromagnetic granitoids (magnetite-type granites),as mentioned by Sant’ovaia and Noronha, (2005).According to Aydin et al. (2007), based on petro-graphic observations and calculations of rockmajor element analyses within granite of Saruhan-Turkey, it indicates the presence of magnetite grains,where the zoning pattern of magnetic susceptibil-ity across the pluton is concentric and reverses.

The aim of the study is to delineate the intrusiverock bodies of submerged Belitung pluton havingsusceptibility and separated from the regionalanomalies of the extensive crystalline and sedi-mentary rocks on the basis of marine magneticdata. It is hoped that the study provides a betterunderstanding of the study area with a consider-able interest for scientific and economic purposes.

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25Magnetic Susceptibilities Distribution and Its Possibly Geological ... Dida Kusnida, et. al.

2. GEOLOGICAL SETTING

Belitung Island (Figure 1) lies between 107°35' -108°18' E and between 02°30' - 03°15' S. To thenorth, it is limited by the South China Sea, byJava Sea to the south, and by Karimata Strait tothe east. The Gaspar Strait separates Belitungand Bangka in the west. It is a residence of theBangka-Belitung Province of Indonesia which isalso includes several smaller islands that lie north-east of South Sumatra Province. Physiographically,Belitung is part of the Sunda Shelf and occurs asa tin belt that extends from Malaysia, Riau Islands,Bangka, and Tujuh Islands. In addition, the mor-phology of Belitung Island is wavy hills and plains.

According to Gafoer et al. (1992), the Bangka-Belitung islands consist of several rock formationssuch as metamorphic rocks (schist and gneiss)of pre-Carboniferous as the oldest rocks. The Cre-taceous-Triassic granites and granodiorites intru-

sive occur as sources of tin. The Triassic sedi-mentary rocks consist of intercalation betweenmetamorphosed sandstones and mudstones withlimestone lenses and quartzite. The Quaternarydeposits that consist of carbonaceous sediments,reefs, calcarenites, mud and Quaternary alluvium(sands and pebbles) are deposited unconformablyon the older rocks.

On the basis of marine seismic reflection recordsand cores in Gaspar Strait, Batchelor and Bowden(1985) indicate four groups of sedimentary rocksthat were deposited since Miocene. Those areyoung alluvium that consists of Holocene sedimen-tary cover and Upper Pleistocene alluvium com-plex, transitional units that consist of marine sedi-ments of Upper Pleistocene and transitional unitof Middle Pleistocene, ancient sedimentary coverof Early-Upper Pleistocene and ancient alluviumplain facies interfingering with fan facies (graniteboulders) and Sunda Plain regolith that consists

Figure 1. Susceptibilities distribution map of submerged Belitung pluton Profiles A-B and C-dare produced in Figure 4

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of Pliocene colluvial deposits and fan materialsand Upper Miocene latosol, laterites and bauxitesderived from the weathering of granites and sedi-mentary rocks.

Batchelor and Bowden (1985) stated that the tindeposits in Belitung were initially sampled by ver-tical pits in areas where cassiterite could be rec-ognized in overburden. In later years, magnetom-eter surveys, followed by pits, then diamond drill-ing located the tin lodes were carried out. Miner-als present within tin ore in general are cassiter-ites while pyrites, quartz, zircons, ilmenites,plumbums, bismuths, arsenics, stibnite, chalcopy-rite, cuprites, xenotimes and monazites are nor-mally additional minerals.

3. METHOD

Data Acquisition and Database

To obtain geomagnetic data, the Marine Geomet-ric G.813 Proton Magnetometer sensor was hauledsome 100 meters behind the vessel. Recording ofobserved data with the precision of 0.1 nT wasperformed on the Soltec 3314 B-MF recorder. Di-urnal variation was measured and recorded usinga stationary ground Geometric G.866 and G.724Magnetometer that were operated on land duringthe cruise. Navigation in the study area was car-ried out by means of the Global Positioning Sys-tem (GPS). Marking of time and fixed point onrecorder was plotted using an Annotator device.

Database for this study is the total magneticanomaly map of Karimata Strait and surroundings(Figure 1). It was compiled and constructed byKusnida et al. (2003) from marine geomagneticdata acquired by Marine Geological Institute ofIndonesia since 1992 until 2003.

Data Correction

Magnetic field intensity measured at the observa-tion point is a resultant of various variables, whilein fact the aim of the geomagnetic survey is mainlyto measure magnetic induction of geological bodycausing anomaly underneath (Peters, 1989). In ageomagnetic survey, the corrections applied areusually diurnal variations. The diurnal correctioncontributes the highest influence in the results ofgeomagnetic measurement. The amount of diur-

nal variation can be observed by measuring mag-netic field intensity at the fixed observation pointat a certain reading interval. Assuming that diur-nal variation is a linear time function, then graphi-cally the amount of diurnal variation correction canbe determined during the measurement.

Technique

– Total Magnetic Anomaly Map

The total magnetic anomaly values were calcu-lated based on equation:

Ftot = Fobs - FIGRF ± Fvar ........................................... (1)

where:(Fobs) : observed total magnetic field(FIGRF) : theoretical earth magnetic field(Fvar) : diurnal magnetic field correction

The diurnal and earth’s field corrections have beenapplied to observed magnetic data, and then thetotal magnetic map, which is contoured, was con-structed. This total magnetic intensity anomalymap is considered to be free from extraneousmagnetic effect and primarily indicate the effectsof geological features underneath.

– Moving Average Filtering

A residual magnetic anomaly studied in this pa-per is referred to intrusive rock bodies that havesusceptibility and are separated from the regionalanomalies of the extensive crystalline and sedi-mentary rocks. Such sedimentary rocks also havemagnetic susceptibilities. Calculation to obtain aresidual magnetic anomaly is directed to deter-mine the susceptibility of causative sources un-derneath. Solution was emphasized on the basisof data filtering that indicates progressively effectof shallow anomaly bodies.

The residual anomaly differentiation by this methodis an indirect process namely the output of themoving average of a regional anomaly. The mov-ing average is a simple mathematical techniqueused primarily to eliminate aberrations and revealsthe real trend in a collections data points. In caseswhere a given waveform is cluttered with noise, orwhere a mean needs to be extracted from a peri-odic signal, a moving average filter may be ap-plied to achieve the desired result.

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According to Weimer (2003), moving average filterallows a great deal of flexibility in waveform filter-ing applications. It can be used as a low-pass fil-ter to attenuate the noise inherent in many typesof waveforms or as a high-pass filter to eliminatedrifting baseline from higher frequency signal.General equation for upward continuation is:

Hz(x,y,-h) = H(r)b(r) ∑= H(0)b + H(1)b + H( 2 )b + H( 5 )b + H ( 9 )b + ... +0 1 2 4

3

..................................................................... (2)

Hz (x, y, -h) : general formula of upward continua-

tion.h : height of upward continuation with

positive direction downwardH(r) : mean upward continuation value at

circle with radius of rb(r) : coefficient factor of circle with ra-

dius r

Susceptibility values distribution of the study areawas obtained by applying equation:

K = IH ............................................................ (3)

Where :k = susceptibility value (cgs unit)I = residual magnetic field intensity (nT)H = earth magnetic field (nT)

However, for detail concerning this technique, thereader is referred to Kusnida and Astawa (2003).

4. RESULTS

The total magnetic anomaly map of Karimata Strait(Figure 2) shows that this area consists of severaldistinct magnetic lineaments that reflect and cor-respond to rock units underneath and more or lessseem to be relate with magnetic province (Figure3) produced by Ben Avraham (1973). In general,except around Bangka-Belitung waters, it is char-acterized by a series of couples and shorts wave-lengths of highs and lows anomalies. The highanomalies in general are characterized by theamplitudes (200 - 400 nT) while the lows are char-acterized by the amplitudes (-200 - -500 nT). This

anomaly province also forms a shield that showsa general southwest - northeast trend crossingJava Sea, and swings to the north-northwest cross-ing Karimata Strait and into Riau Islands and Ma-laysia Peninsula as well. This total magneticanomaly province seems to correspond and ap-proximately parallel to the major structural ele-ments in this area, which is the Jurassic-Triassicmagmatic arc of Malaysia-Sumatra-SE Kalimantan(Soeria Atmadja et al., 1998).

Southern waters of Kalimantan and eastern JavaSea are characterized by relatively high-level withisolated total magnetic anomalies that have shortwavelengths, gradual and varied amplitudes of lessthan 200 nT. These small isolated anomalies pos-sibly relate to small near-surface magnetic bod-ies. In central Java Sea, they occur on both sidesof the Karimun Arch and probably indicate the pres-ence of dike along the faulted flanks of the arch(Ben Avraham, 1973). The gradually and almostno significance change in total magnetic anoma-lies characteristics in the Java Sea suggest thatthe arch composes of rock with very low magneticsusceptibility, possibly granite and implies thatthe igneous rocks are deep as proven by the evi-dent from the seismic profiles (Emery et al., 1972).

The Bangka-Belitung plutonic massive seems tobe clearly recognized by very broad low-positivemagnetic anomalies (less than 50 nT) or no mag-netic anomalies. This smooth magnetic provinceis the result of several different factors. It may bedue to the great depth of burial of magnetic base-ment or to a regional metamorphism that de-creased the magnetization of the basement rocks(Ben Avraham, 1973). Around the islands ofBangka and Belitung, smooth magnetic field isthe results of low-positive susceptibilities of wide-spread granitic basement. Susceptibilities distri-bution map (Figure 1) indicates that contour val-ues between 0.001 cgs unit and 0.003 cgs unitportray a magnetic bearing massive zone of theextension of submerge Belitung granite. In con-trast, the surrounding susceptibilities distributionwith contour values of <0.001 cgs unit and >0.003cgs unit portray a magnetic bearing basement ofregional magnetic anomalies. On the basis ofmagnetic susceptibilities distribution map men-tioned above, the Belitung magnetic high is delin-eated by susceptibilities values between 0.001 cgsunit and 0.003 cgs unit (Figure 4).

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Figure 2. Total magnetic anomaly map of Karimata Strait and surrounding. The submergedBangka-Belitung plutonic islands seem to be characterized by < 50 nT contourvalue indicated by dash line

Figure 3. Magnetic provinces over the Sunda Shelf (Ben Avraham, 1973). A typical magneticanomaly from each province is shown in the legend

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5. DISCUSSION

Magnetic anomalies are caused by all of largerplutonic bodies and other magnetic anomalies maypossibly be caused by granitic intrusive. Althougheach exposed intrusive bodies in Bangka-BelitungIslands have been known as granites, a distin-guishing in the magnetic properties is shown bythe variety of magnetic expression. A low-positiveof total magnetic anomaly less than 50 nT withthe susceptibility values range from 0.001 – 0.003cgs unit occurs immediately within the Belitungwaters, even tough hundreds of kilometers offshorethe island, the magnetic field is depressed.

Susceptibility measurements on hard samplesconfirm that the granites are magnetic and sus-ceptibility values vary from 0.001 to 0.05 cgs unitfor granite in the eastern Lachlan fold-Australia(Connelly, 1979). The granites have been groupedby chemical criteria into I-types which are purelyigneous origin and S-types which have been de-rived by partial melting of sedimentary rocks thatwas remained at depth as a large body and didnot move laterally for any great distance. How-ever, other study also indicates that all the gra-nitic plutons are geochemicaly classified ascalcalkaline I-type granitoids in volcanic arcs. Theyhave a susceptibility values of 0.001 to 0.03 cgsunit such as Abukuma granites in Japan that cor-respond to magnetite-series and/or ilmenite se-

ries granites (Atsushi and Tetsuichi, 2003) and0.03 – 0.06 cgs unit for Natuna granites (BenAvraham, 1973).

According to Aryanto et al. (2005), based on theirstudy in Kelumpang-Belitung Island, it indicatesthe granitic rocks type of the area is I-type of bi-otite-granite and is associated with cassiteriteminerals. Therefore, this concludes that the mag-netic properties of the Belitung waters can con-ceive because of the submersion of this granitetype. However, a width estimate, determined fromthe delineating the pluton, indicates that the sourceof the low-positive magnetic anomaly is deep be-low the sea. The 0.001 to 0.003 cgs unit suscep-tibilities value of the submerged Belitung graniticpluton is confirmed with the general I-type gran-ites in the world.

The most prominent positive magnetic features arelocated at the southwest corner and near the north-west boundary of the area of Figure 1. Schwartzand Surjono (1991), stated that the Pemali tindeposit of Bangka is located in a Triassic granitepluton, which is characterized by a decrease ofcompatible Ca, Mg, Ti, P and Zr in the sequence:medium to coarse-grained biotite granite,megacrystic medium-grained biotite granite, two-mica granite/muscovite granites. The tin mineral-ization is confined to the two-mica granite andconsists of disseminated cassiterite as well as

Figure 4. Profiles A-B (above) and C-D (below) show the range of susceptibilities values of theBelitung Pluton indicated by 0.001 - 0.003 cgs

Belitung Pluton

A B0.04 cgs

0.02

0.00

-0.02

0 50 100 150 200 250 333 Km300

0 50 100 150 200 250 333 Km300

C D0.02 cgs

0.00

-0.02

Belitung Pluton

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greisens-bordered veins. The highly evolved mus-covite granite is tin-barren and is distinguished fromthe two-mica granite by its low mica content andlow loss-on-ignition values.

6. CONCLUSION

Low-positive anomalies delineating submergedintrusive features occur around Belitung Island. Anelliptical low-positive anomaly is superimposed onan elongate, 0.001- 0.003 cgs unit magnetic sus-ceptibilities values. This submerged intrusive pos-sible economic interest, and the nature of this in-trusive is suggested to be granitic pluton of bi-otite-granite that is associated with cassiteriteminerals. This low-positive anomaly may representan intrusive similar to the granite with which thetin deposits are affiliated.

ACKNOWLEDGEMENTS

The authors wish to thanks T.A. Soeprapto fromMGI for kindly help during data processing andmagnetic map construction using the ER-Mapperand Global-Mapper software. We express ourthanks to our respective institution, Marine Geo-logical Institute of Indonesia. Our gratitude is alsodirected to various scientific teams who have spenttheir time during geomagnetic data acquisition.

REFERENCES

Aryanto, N.C.D., Nasrun, A.H Sianipar dan L.Sarmili, 2005. Granit Kelumpang sebagai gran-ite tipe-I di Pantai Teluk Balok, Belitung, JurnalGeologi Kelautan, vol. 3. no. 1.

Atsushi, K. and Tetsuichi, T., 2003. Geology andpetrography of the Abukuma granites in theFunehiki area, Fukushima Prefecture, NE Ja-pan., Journal of the Geological Society of Ja-pan, Vol.109, No.4(20030415), p. 234-251.

Aydin, A., E. C. Ferré and Z. Aslan, 2007. Themagnetic susceptibility of granitic rocks as aproxy for geochemical composition: Examplefrom the Saruhan granitoids, NE Turkey,Tectonophysics, vol. 441, p. 85-95.

Batchelor, R.A. and Bowden, P., 1985. Petroge-netic interpretation of granitoid rock series

using multicationic parameters. ChemicalGeology, 48, p. 43-55.

Ben Avraham, Z., 1973. Structural Framework ofthe Sunda Shelf and Vicinity, PhD Theses,Massachusetts Institute of Technology, 269 p.

Connelly, J.B., 1979. Interpretation of subsurfaceshape of granites in the eastern Lachlan foldbelt using aeromagnetic data, Bulletin of theAustralian Society of Exploration Geophysi-cists, 10(1), p. 92-95.

Emery, K. 0., Uchup, J. Sunderland, Uktolseja,H. L. and Young, E. M. 1972. Geological struc-ture and some water characteristics of the JavaSea and adjacent continental shelf. United Na-tions ECAFE, CCOP Techn. Bull. Vol. 6.

Ferré, E.C., Wilson, J. and Gleizes, G., 1999.Magnetic susceptibility and AMS of theBushveld alkaline granites, South Africa.Tectonophysics, 307, p. 113-133.

Gafoer, S., Amin, C and Satiogroho, 1992. Geo-logical Map of Indonesia, Palembang Sheet,Scale 1 : 1.000.000, Geol. Res. Dev. Centerof Indonesia.

Gleizes, G., Nédélec, A., Bouchez, J.L., A., A.and Rochette, P., 1993. Magnetic suscepti-bility of the Mont Louis - Andorra ilmenite -type granite (Pyrenees): a new tool for thepetrographic characterization and regionalmapping of zoned granite plutons. Journal ofGeophysical Research: Solid Earth, 98(B3),p. 4317-4331.

Ishihara, S., Hashimoto, M. and Machida, M.,2000. Magnetite/ilmenite series classificationand magnetic susceptibility of the mesozoic-cainozoic batholiths in Peru. Resource Geo-logy, 50, p. 123-129.

Kusnida, D., T. Azis dan A. Yuningsih, 2003, To-tal Magnetic Anomaly Map of Selat Karimataand Surroundings, Scale 1:1.000.000. MarineGeological Institute of Indonesia.

Kusnida, D. and I.N. Astawa, 2003. Weight Mov-ing Average Filtering Technique on Total Mag-netic Anomalies of the South-western offshoreof Kalimantan, Bull. of Mar. Geol., Vol. 18,no. 3.

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Pamungkas, P., 2006, Kajian PertambanganTimah Kita, World Press.Com.

Peters L.J., 1989. The Direct Approach to Mag-netic Interpretation and Its Practical Applica-tion, AAPG Treatise of Petroleum GeologyReprint Series.

Santovaia, H. and Noronha, F., 2005. Classifica-tion of Portuguese Hercynian granites basedon petrophysical characteristics, http://www.ucm.es./BUCM/compludoc/S/10704/02134497_1.htm

Schwartz, M. O. and Surjono, 1991. The Pemalitin deposit, Bangka, Indonesia, Mineralium De-

posita, Vol. 26., no.1.

Soeria Atmadja, R., Suparka, S., Abdullah, Ch.,Noeradi, D and Sutanto, 1998, Magmatism inwestern Indonesia, the trapping of the SumbaBlock and the gateways to the east ofSundaland., Journ. of Asian Earth Sciences.,Vol. 16, No. 1., p. 1 - 12.

Tarling, D.H. and Hrouda, F., 1993. The magneticanisotropy of rocks. Chapman & Hall, London,217 p.

Weimer, M.R., 2003. A closer look at the advancedCODAS moving average algorithm.htm.

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THE AVAILABILITY OF INDONESIAN OIL PRODUCTTHAT IS USED IN THE UPGRADED BROWN COAL

PROCESS

Iwan Rijwan, Bukin Daulay and Gandhi Kurnia HudayaR&D Centre for Mineral and Coal Technology

Jalan Jenderal Sudirman 623, ph. 022-6030483, fax. 022-6003373, Bandung 40211email : [email protected], [email protected], [email protected]

Received : 13 November 2007, first revision : 21 April 2008, second revision : 26 May 2008,accepted : June 2008

ABSTRACT

Indonesian coal has a potential to be a major future primary energy source due to its large resource,easy and low cost of exploitation, good quality and supported by appropriate infrastructure. However,more than 65% of the coal resources are categorized as LRC and this type of coal needs to beupgraded before it is used and transported for a long distance. One of the upgrading processes isUBC. Kerosene, LSWR and spray oils are used for UBC process as heating media, material forclosing coal pores and oil for briquette machine, respectively.

The specification and price of kerosene in Indonesia which is used for both household and industriesare controlled by PT PERTAMINA. However in the case of LSWR, PT PERTAMINA does not controlthe quality and the price. Therefore in the market there are different of qualities and prices of LSWR.All oil refineries belong to PT PERTAMINA produces LSWR and kerosene. They guarantee the con-tinuity of oil supply to customer. They recommend to utilize a heavy aromatic for kerosene substitu-tion and asphalt and decant oil to substitute LSWR. The oil will be transported to the UBC plant fromthe nearest oil refinery using lorries or tankers transportation agency that is recommended by PTPERTAMINA.

Keyword: UBC, kerosene, LSWR, spray oil, oils for UBC and oils substitute

1. INTRODUCTION

Several upgrading techniques have been success-fully developed around the world (Allardice andYoung, 2001; Favas and Jackson, 2003), howeverUBC process that was originally developed by KobeSteel Ltd. of Japan as a pretreatment for browncoal liquefaction process is one the most advancedsolutions of upgrading, due to its relatively simpleand mild process, indicated by its lower pressureand temperature. The benefit of coal upgradingincludes the increasing of value added to the coal,both for export and domestic markets, stabilizingof coal quality feed for power generation and otherindustries, increasing combustion efficiency andreduces CO2 emission.

In order to implement the UBC in coal industry,Indonesia in cooperation with JCOAL and KobeSteel Ltd. of Japan are developing a demonstra-tion plant in Satui, South Kalimantan with the pro-duction capacity of 600 tons/day or 1,000 tons/day feed. This demonstration project is startedsince April 2006 for engineering design and nowis conducting civil work and manufacturing the mainequipments. The operation of this plant is expectedto commence in 2008. After the demonstrationstage, it is expected to proceed the commercialstage with the plant capacity of 5,000 tons/day or1.7 million tons/year that will be operated in 2012.

The UBC process consists of the following fivesections, i.e. Fine Coal Handling, Slurry Dewa-

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33The Availability of Indonesian Oil Product Which is Used in ... Iwan Rijwan, et. al.

tering, Coal/Oil Separation, Oil Recovery andBriquetting, as shown in Figure 1.

A pilot plant scale in Palimanan, Cirebon with thecapacity of 5 tons/day has been established since2003. The UBC process can upgrade LRC intocoal of 6000 – 6800 kcal/kg (air dried basis/adb)heating value, mostly through moisture contentreduction technique from 20 – 40% in the feedcoals to be less than 5% in the dewatered prod-uct. The final product can be UBC powder, slurryor briquette, and it is very stable after the coal hasreached equilibrium conditions with minimum pol-lution of the waste water.

Small amount of low sulphur wax residue (LSWR)or asphalt is added to the UBC process to preventthe re-absorption of moisture. Besides that, theaddition of heavy LSWR or asphalt to the slurry iseffectively adsorbed many small pores of the LRC tomake it waterproof and to give the effect of prevent-ing self-heating caused by moisture rebound andwetting heat. The LSWR or asphalt was used asresidual oil in UBC process because they have highboiling point upper than 250°C in distillation curve,then when oil recovery process LSWR or asphaltstill inside coal pore not recovered with keroseneas recycle oil and will be acted as pores coatingagent to prevent moisture rebound into the coal.

Figure 1. Block flow diagram of UBC process

Raw Coal Fire CoalHandling

SlurryDewatering

Fine Coal

WasteWater

DewateredSlurry

Coal/OilSeparation

Oil Recovery Briquetting

Oil WetUBC

UBC(Fine)

UBC(Briquette)

Recycle OilUBC : Upgraded Brown Coal

Before Slurry Dewatering After Slurry Dewatering

CAPILLARY WATER

SURFACE WATER

Oil soaks into the pores, and asphalt is selectively adsorbed

Asphalt

Figure 2. Principle of the UBC process

Raw coal is crushed to generally under severalmm and mixed with Light oil (kerosene) to makeslurry. It is then sent to a shell & tube evaporatorto be heated and dewatered. The vapor, evapo-rated by the heat is compressed with a compres-sor, sent to the shell side of the evaporator andbecomes the heat source for dewatering, thusgreatly reducing the separating energy. Young coalsuch as brown coal has many small pores. Spon-taneous combustion is caused when these poresadsorb oxygen and gain heat. The heavy oil addedto the recycle oil is effectively adsorbed to thesepores to disable the active site of spontaneouscombustion, to make the coal waterproof and togive the effect of preventing self-heating causedby moisture rebound and wetting heat. Figure 2illustrates the process.

Light oil (kerosene) has been use as heating me-dia for slurry dewatering in UBC process. The kero-sene also has function as material for makingslurry, start up oil, make up oil and recycle oil.

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The kerosene was used in this process becausehave low boiling point at below 100oC and recov-ered 90% at 180oC, than we can recovered the oilas recycle oil at oil recovered process with pro-cess condition about 200oC. The kerosene alsocan be well mixing with coal to produce homog-enous slurry, so the slurry not easy to sedimenta-tion during the slurry dewatering process.

In addition, spray oil is used for briquette machineto produce briquette with a good shape. When thefine coal will be briquetted and put to double rollbriquette machine it needs oil (spray oil). We callspray oil because the oil was sprayed to the doubleroll briquette machine to make briquette smoothlyreleased. The kind of spray oil can be any kind ofresidual oil with no metal content to meet a goodenvironmental impact.

The actual kerosene, LSWR and spray oil specifi-cation on Indonesian industry standard should be

- To investigate the availability of kerosene andLSWR substitute as light oil and residual oil,respectively those are used for the UBCprocess.

2. METHODOLOGY

The methodology of this research is site surveyand study literature to investigate specification,production capacity and transportation method atkerosene, LSWR, briquette machine spray oil andthe substitution potential of those oil.

3. RESULTS AND EVALUATION

Based on the experience in UBC pilot plant op-eration, the estimation of light oil, residual oil andspray oil consumption for UBC demonstration andcommercial plants is shown in Table 1.

investigated to anticipate the quality, especiallydensity and the distillation character from somerefineries, because the facilities, operation condi-tion, and the raw of crude oil are different in eachrefinery. The actual specification of kerosene,LSWR and spray oil can influence the UBC pro-cess condition and UBC product.

The objectives of this study are:- To review the oil availability for UBC commer-

cial plant such as kerosene, LSWR and bri-quette machine spray oil to meet continuityoperation of UBC commercial plant;

- To investigate the price and specification ofkerosene, LSWR and briquette machine sprayoil to meet economic view point;

- To investigate the recommended transporta-tion method and delivery cost estimation ofkerosene, LSWR and briquette machine sprayoil from the refineries; and

3.1. Kerosene

Indonesia became a net petroleum importer on amonthly basis in July 2004. As a result, Indonesiabecame a net importer of fuel products for the en-tire year. Oil trade deficits reached 29 million bar-rels or almost 81,000 b/d in 2004. Full year officialstatistics for 2005 are likely to indicate a contin-ued trend toward net importer status. However,the GOI move in October 2005 to remove substan-tial subsidies for domestic fuels, raising averagefuel prices by an unweighted 126 percent, will pro-vide a strong balance to the continued decline indomestic production and stagnant refining capac-ity. Fuel consumption increased 8 percent in 2004to 64.7 million kiloliters (KL), up from 59.9 millionKL in 2003 and 57.8 million KL in 2002. The Go-vernment of Republic Indonesia (GOI) is project-ing 41.6 million kiloliters of domestic fuel consump-tion in 2006, a drop of 36 percent from 2004.

Table 1. Consumption of light, residual and spray oil for UBC demonstration and com-mercial plants

Plant Type Plant ConsumptionCapacity Light oil Residual oil Spray oil

Demonstration Plant 600 tons/day 3 tons/day 3 tons/day 3 tons/dayCommercial Plant 5,000 tons/day 25 tons/day 25 tons/day 25 tons/day

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Consumption in 2004 increased in each categoryof fuel except for kerosene and industrial dieseloil. A significant part of the increase likely resultedfrom the smuggling of subsidized fuel products toneighboring countries and domestic adulterationactivities. In 2004, fuel product imports increasedto 422,000 b/d from 292,000 in 2003.

The majority of domestic consumption is for trans-portation (46.7 percent), industry (24.6 percent),household use (18.2 percent) and electric power(10.5 percent). The transportation sector useslargely automotive diesel oil (ADO), while house-holds are the largest consumers of kerosene.

Pertamina controls the sale of gasoline and auto-motive diesel by direct ownership and franchise ofclose to 3,000 gasoline stations nationwide.Pertamina itself only owns 2% of the retail sta-tions. The private sector also sells kerosene. Theselling price of fuel oil on the domestic market,excluding industry fuels, is determined by the gov-ernment. Starting in 2005, the government beganto adjust prices for high grade automotive fuelsand industry fuels according to market prices.

In 2004, Indonesia’s production of petroleum-basedfuels and non-fuels from domestic refineriesdropped to just under 1 million b/d, largely due toa decreased supply of domestic crude. Most ofthe petroleum products refined in Indonesia aredestined for domestic consumption. Indonesia hasnine oil refineries, all owned and operated by stateoil and gas company Pertamina, with a combinedinstalled capacity of 1.06 million b/d. Accordingto government figures, on average Pertamina’srefineries operated at 95% of their combined ca-pacity of 1.056 million b/d in 2004.

Kerosene is a fuel oil of clear chromatic distillatetype. The usage of kerosene in general is for fuelsin household, although some industries utilizekerosene for a few equipments of its combustionprocess and as a raw material.

The industrial price of kerosene in 2007 is approxi-mately Rp. 5,000 to Rp. 6,000 as shown in Figure 3.

The quality (specification) of kerosene in the mar-ket, both for household and industry is the samealthough it is derived from different refineries as

Table 3. Oil refinery production (1000b/d)

Refinery Installed Crude ProcessedCapacity 2003 2004

Pangkalan Brandan 5 2.6 2.3Dumai 120 28.9 22.1Sungai Pakning 50 47 48.6Musi 133.7 113.3 107.4Cilacap 348 351.4 332.5Balikpapan 260 246.5 264.3Balongan 125 114.8 111.9Kasim 10 8.4 8.4Cepu 3.8 2.3 2.2

TOTAL 1.055.5 1,015.2 999.8

Table 2. Domestic fuel consumption (million liters)

Products 2000 2001 2002 2003 2004

Auto Diesel 21,735 23,014 24,213 25,636 26,488Gasoline 12,422 13,057 13,732 14,112 17,027Kerosene 12,455 12,279 11,678 12,262 11,846Fuel Oil 6,013 6,121 6,260 6,321 5,755IDO 1,451 1,420 1,360 1,403 1,093Avtur 744 n/a 553 124 2,438Avgas 5 n/a n/a 8 3

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can be seen in Table 4. The quality and the priceof the kerosene in the country are controlled bystate oil and gas company, PT PERTAMINA.

3.2. LSWR

LSWR is the bottom product of Indonesian oil re-fineries. The refineries that produce LSWR includeCilacap, Balikpapan, Dumai, Pangkalan Brandan,Sorong and Plaju. Currently, Indonesian oil refin-ery exports LSWR to Japan and Korea. In thosecountries, LSWR is processed to produce oils.Some Indonesian industries also use LSWR asfuel oil for boiler. Recently, the refineries also pro-cess LSWR to produce oils. Tables 5 and 6 showthe product specifications of LSWR from Plaju andCilacap refineries, respectively.

PT PERTAMINA does not provide LSWR price tothe public, because there is not standard price ofLSWR. The price of the LSWR can be negotiatedby a contract or purchase agreement. The Refin-

0

2000

4000

6000

8000

10000

1 2 3 4 5 6 7Month

Pri

ces,

Rp.

Figure 3. Trend of industrial keroseneprice in Indonesia in 2007

Table 5. Product specifications of LSWR from Plaju refinery

No PropertiesLimit Test Method

Min Max ASTM

1 Specific Gravity at 60/60 oF 0.8789 0.9309 D-12982 A.P.I Gravity, 60oF 20.5 29.5 D-12503 Pour Point, oF - 120 D-974 Conradson Carbon Residue, % wt. - 8.00 D-1895 Water Content, %vol. - 0.50 D-956 Ash Content, %wt. - 0.10 D-4827 Sulphur Content, %vol. - 0.20 D-15518 Flash Point PM CC, oF 166 - D-939 Viscosity Redwood I/140oF, sec. 100 350 By Conversion from D-445

Table 4. Specifications of kerosene

No PropertyLimit Test Method

Min Max ASTM Other

1 Octane grade 80.0 85.0 D-2699 -2 Specific gravity 60/60 F - 0,8262 D-4052 -

DISTILLATION : - - D-86 -• 10% vol. evap. To °C - 74 - -• 50% vol. evap. To °C 88 125 - -• 90% vol. evap. To °C - 180 - -

3 Smoke Point, MM 18 - D-1322 -4 Chart Value, mg/kg - 6.45 - IP-105 Flash Point, oF - 117 - IP-1706 Sulphur Content % mass - <0.015 D-1266 -7 Corrosion of copper sheet - No.1 D-130 -

(3 hour/500C)8 Color & Odour Marketable - - Organoleptic

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eries also do not control the quality of LSWR be-cause every refinery produces the different speci-fications of LSWR.

be seen in Table 6. The refineries are located inSumatera, Java, East Kalimantan and Papua ascan be seen in Figure 4. They produce a mix of oil

fuels (diesel, fuel oil and kerosene), liquefied naturalgas, secondary fuels (such as naphtha) and non-fuels (such as LSWR, asphalt and lubricants).

Pangkalan Brandan: This is small; aging refin-ery consists of a simple (primary) distillation unit,without a secondary processing unit. PangkalanBrandan has a processing capacity of 5,000 bar-rel/day.

Dumai: The refinery has a primary and a second-ary processing unit (Hydro Cracker) that producesliquid petroleum gas (LPG), naphtha, high vacuumgrade oil (HVGO) and green coke. Its processingcapacity is 120,000 barrel/day.

Sungai Pakning: Built at around 1957, the plantrefines heavy paraffin crude oil to produce dieseland paraffin and has a capacity of 50,000 barrel/day.

Plaju/Musi: The aged refinery was built by shellin 1930. It consists of both a primary and a sec-ondary processing unit. The secondary unit, a fuelcatalytic cracker unit (FCCU), processes up to135,000 barrel/day and was designed to producepolyetilene tetra amine (PTA) and polytam.Pertamina has proposed to convert the facility intoa petrochemical plant by 2008.

Cilacap: The Indonesia’s largest refinery. Cilacapis located in Central Java with 348,000 barrel/dayin capacity. Its products are premium fuel, kero-

Table 6. Product specifications of LSWR from Cilacap refinery

No PropertiesLimit Test Method

Min Max ASTM

1 Specific Grafity at 60/60 °F - 0.9174 D-12982 A.P.I Gravity, 60°F - 22.74 D-12503 Pour Point, oF - 105 D-974 Conradson Carbon Residue, % wt. - 4.20 D-1895 Water Content, %vol. - 0.10 D-956 Ash Content, %wt. - 0.008 D-4827 Sulphur Content, %vol. - 0.22 D-15518 Flash Point PM CC, °F 170 - D-939 Viscosity Redwood I/140°F, sec. - 166 By Conversion from D-445

3.3. Spray oil for briquette machine

Lube base oil can be used as briquette machinespray oil. Lube base oil is a hydrocarbon com-pound that is produced by a distillation process ofvacuum long residue at Lube Oil Complex I/II/III atIndonesian refinery processing Unit IV Cilacap.Lube base oil is used as material for making oflubricating oil. This material is blended and addedwith additive to be lube oil such as “mesran” andother brand name found in the market. There arefour types of the lube base oils namely HVI-60 orSN-150, HVI-95 or SN-200, HVI-160S or SN-500and HVI-650. That oil can be used as spray oil forbriquetting process; the different of each is onlythe viscosity of oil product. We can select thecheaper one to meet an economical view of UBCcommercial plant. Table 7 shows specificationsof the lube base oils.

Production Capacity of the lube base oil is asfollows:1. HVI-60 = 69,400 tons/year2. HVI-95 = 108,500 tons/year3. HVI-160s = 104,600 tons/year4. HVI-650 = 145,500 tons/year.

3.4. Transportation Method

Indonesia has nine oil refineries, all of the refiner-ies are belong to and operated by state oil andgas company PERTAMINA, with a combined in-stalled capacity of 1.06 million barrel/day as can

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Table 7. Product specifications of lube base oil

Properties Method HVI-60 HVI-95

Viscosity at 100°C sCt ASTM 0-445 4.4 - 4.9 6.7 - 7.4Viscosity index (min) ASTM 0-2270 95 95Flash Point PMCC, °C (m) ASTM D-93 204 210Pour Point, °C (max) ASTM D-97 -15 -9Total Acidity, mg KOH/g (max) ASTM D-974 0,05 0,05Ash Content, % wt (max) ASTM 0-482 0,01 0,01Color ASTM (max) ASTM 0-1500 1,5 2Cloud Test SMS-1694 no cloud no cloudAppearance Visual clear & blight clear & blight

Properties Method HVI-160S/160B HVI-650

Viscosity at 100°C. cSt ASTM 0-445 10.7 - 11.8 30.5 - 33.5Viscosity index (min) ASTM 0-2270 95 95Flash Point PMCC. °C (min) ASTM D-93 228 267Pour Point, °C (max) ASTM D-97 -9 -9Total Acidity, mg KOH/g (max) ASTM D-974 0,05 0,05Ash Content, % wt (max) ASTM 0-482 0,01 0,01Color ASTM (max) ASTM 0-1500 0,3 0,4Cloud Test SMS-1694 no cloud no cloudAppearance Visual clear & blight clear & blight

Notes:1. HVI = High Viscosity Index2. SN = Solvent Neutral3. BS = Bright Stock

Figure 4. Location of Indonesian oil refineries

INDONESIAN OILS REFINERY

KALIMANTAN

SUMATERA

DumaiBalikpapan

PangkalanBrandan

SULAWESI

PAPUA

Kasim

Cilacap

JAWA

Musi

BalonganCepu

Sungai Pakning

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sene, diesel, fuel oil, and naphtha.

Balikpapan: The Balikpapan refinery in EastKalimantan is more modern than that of Cilacapand Dumai, and consists of both a primary unitand secondary processing (Hydro Cracker) unit.The Plant has a refining capacity of 220,000 bar-rel/day. Bechtel upgraded the refinery in 1983. Dueto the facility design, the plant cannot processcrude from nearby domestic producers (Total,Chevron, Talisman and VICO).

Balongan: Indonesia’s newest state-owned refin-ery at Balongan in West Java has capacity to pro-cess 125,000 barrel/day of domestic crude. It hastwo production units: the crude distillation unit(CDU) and the residue catalytic cracking unit(RCCU). The RCCU, one of the world’s largest,has a processing capacity of 83,000 barrel/day.

Kasim: This is a small refinery located in Papuaand has only a simple primary distillation unit. Itsmain products are premium fuels, diesel and kero-sene.

Pertamina’s Downstream Directorate is respon-sible for the distribution of fuel products to end-users from 174 storage depots throughout Indo-nesia. The Directorate has established eight re-gional representative offices to market the prod-ucts. Fuel products are transported via an elabo-rate pipeline network and by tank trucks, rail tankwagons, tank vessels and barges.

Oil that will be used for UBC plant will be trans-ported from oil refinery by lorries or tankers. Incase of the UBC plant in Satui, South Kalimantanthe oil will be transported from Balikpapan oil re-finery. If the UBC plant located in Pendopo, SouthSumatera, the oil will be transported from Plaju oilrefinery.

In case of LSWR, PT PERTAMINA storages theresidue in twelve tanks with each capacity of70,000 barrel. LSWR is sent to a port by pipe linewith a diameter of 10 inch for about 1 KM in lengththat equipped by steam trace.

According to the safety regulation and also theavailability of infrastructure in oil refinery, LSWRcan only be loaded to tanker. The LSWR will beloaded through pipe line by loading arm to thetanker with LSWR flow rate of 800m3/h and mini-mum capacity of tanker is 200,000 barrel. Afterloading the LSWR, the pipes and pumps are

cleaned (flushing) by automotive diesel oil (ADO)of 75 m3. Inventory LSWR in the pipe line is about70 m3, therefore the total of ADO generated is145 m3. This oil is also loaded to the tanker and itis mixed with LSWR.

3.5 Kerosene and LSWR Substitution

(1) Heavy Aromatic (Kerosene Substitution)Heavy Aromatic is produced by PTPERTAMINA’s Paraxylene refinery in Cilacap.It was constructed in 1988 and began opera-tion after its inauguration by the President onDecember 20, 1990. The total capacity of thisrefinery is 590,000 tons/year with the range ofproduction: paraxylene, benzene, LPG,raffinate, heavy aromatic, and fuel gas/excess.The price of heavy aromatic will be negotiatedwith PT PERTAMINA. Product specificationof heavy product from some refinery belong toPT PERTAMINA is shown in Table 8. Heavyaromatic was suggested by PT PERTAMINAResearch and Laboratory Services due to simi-larity of physical characteristic of heavy aro-matic and small different in the specific grav-ity with kerosene. Another reason is abundantproduct of heavy aromatic, which until now notutilize yet so we can get the product withcheap price. The price of oil which used atUBC process will affect to the economic viewof UBC commercialization. However, weshould be tested at UBC laboratory scale toconfirm the effect of that oil to UBC product.

(2) Asphalt (LSWR substitution)Asphalt can be used as LSWR substitutionbecause it has a similarity in the physical prop-erties and specific gravity of that oil. Anotherreason is availability of asphalt transportationinfra structure. Regarding to infra structure inPERTAMINA refinery the LSWR should betransported by used tanker with minimum ca-pacity of 200,000 barrel. In another hand, as-phalt can be transported to the site by usinglorry with minimum capacity of 5000 liter. Thecharacteristic of asphalt that is produced byIndonesian oil refinery UP IV Cilacap fromsemisolid asphallic oil cure is non metallicdissolve in CS2 (carbon disulphide). The char-acteristic of asphalt is water proofing and ad-hesive.

Indonesian refinery has produced asphalt forlong time and guarantees the continuity of sup-ply. Production capacity of asphalt from oil

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refinery UP IV Cilacap is 650,000 tons/year.There are two grades of asphalt that producedby oil refinery UP IV, they are asphalt pen-etration 60/70 and 80/100. Product specifica-tion of asphalt penetration 60/70 and 80/100can be seen in Table 9 and 10, respectively.

Table 8. Product specification of heavy aromatic

No Analysis Method Result

1 Spec. Gravity 15.5/15.5 °C D-4052 0.9091 - 0.92552 Flash Point °C D-93 136 - 1443 Distilation D-850

IBP °C 168 - 174FBP °C 330 - 335

4 Composition % wt UOP-744C9 Aromate 48.18CIO Aromate 22.38C10 + Aromate 29.44

5 Colour ASTM 0.4

(3) Decant Oil (LSWR substitution)Another recommendation to substitute LSWRis decant oil, because it has similarity in physi-cal properties with LSWR. Same as heavyaromatic the decant oil product not utilize yetso we can have that oil with more cheap price

Table 9. Product specification of asphalt penetration 60/70

No ParameterSpecification

Min Max

1 Penetration 25°C 100 g 5 second, mm 60 792 Softening Point 48 583 Flash Point (Cleveland Open Cup), °C 200 -4 Loss weight 163 °C, 5 hour, wt% - 0,45 Dissolve in C S2 or CCL4, wt% 99 -6 Ductility 25 °C, 5 cm per minute, cm 100 -7 Penetration after percentage weight

loss towards the real weight, % 75 -8 Weight density 25/25 °C 1 -

Table 10. Product specification of asphalt penetration 80/100

No ParameterSpecification

Min Max

1 Penetration 25°C 100 g 5 second, mm 80 992 Softening Point (Ring & Ball), °C 46 543 Flash Point (Cleveland Open Cup), °C 225 -4 Loss weight 163 °C, 5 hour, wt% - 0,45 Dissolve in CS2 or CCL4, wt% 99 -6 Ductility 25 °C, 5 cm per minute, cm 100 -7 Penetration after percentage weight

loss towards the real weight, % 75 -8 Weight density 25/25 °C 1 -

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compared to LSWR or asphalt. Decant oil isone of the product derived from distillationsfrom crude oil at oil refinery in Balongan.

In Average, the production capacity of decantoil from oil refinery in Balongan is 500,000 tons/year. Table 11 shows the product specifica-tions of decant oil from oil refinery in Balongan.

Table 11. Product specification of decant oilfrom Balongan’s oil refinery

No Parameter Specifi-cation

1 Specific Gravity at 60/60, °F 0.98342 API Gravity 7.83 Pour Point, °C -1.54 Vickositas at 50 °C, cSt 14.415 Flsh Point PMMC, °C 806 WW Content, % vol 0.357 Sulfur, % wt 0.128 Metal Content as Al + Si, ppm 353

4. CONCLUDING REMARKS

1. The quality and the price of kerosene in Indo-nesia are controlled by state oil and gas com-pany, PT PERTAMINA.

2. The price of the LSWR can be negotiated bya contract or purchase agreement. The Refin-eries also do not control the quality of LSWRbecause every refinery produces the differentspecifications of LSWR.

3. Lube base oil can be used as briquette ma-chine spray oil. Lube base oil is used as ma-terial for making lubricating oil. The quality oflube base oil is controlled by PT PERTAMINAand the price of the base oil can be negoti-ated by a contract or purchase agreement.

4. Oil that will be used for UBC plant will be trans-ported from oil refinery by lorries or tankers. Incase of the UBC plant in Satui, SouthKalimantan the oil will be transported fromBalikpapan oil refinery. If the UBC plant lo-cated in Pendopo, South Sumatera, the oilwill be transported from Plaju oil refinery.

5. Heavy aromatic oil is recommended to sub-stitute kerosene, and asphalt or decant oil tosubstitute LSWR, because of their similarproperties.

REFERENCES

Allardice, D. J. and Young, B. C., 2001. Utiliza-tion of low rank coals, 18th Annual Interna-tional Pittsburgh Coal Conference.

Centre of Geology Resources, 2007. IndonesiaCoal Resources, Agency of Geology, Minis-try of Energy and Mineral Resources.

Favas, G. and Jackson, W. R. 2003, Hydrother-mal dewatering of lower rank coals: Effects ofprocess, Fuel, vol. 82, p. 53–57 (2003).

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PETROGRAPHIC ANALYSES OF COAL DEPOSITSFROM CIGUDEG AND BOJONGMANIK AREAS WITH

REGARD TO THEIR UTILISATION

Binarko Santoso and Nining Sudini NingrumR&D Centre for Mineral and Coal TechnologyJalan Jenderal Sudirman 623 Bandung 40211

Ph. 022-6030483, fax. 022-6003373, e-mail: [email protected]

Received : 04 December 2006, first revision : 04 February 2008, second revision : 29 April 2008,accepted : June 2008

ABSTRACT

Geological setting of the Cigudeg and Bojongmanik areas gives rise to the coal characteristics, par-ticularly due to the depositional environment and stratigraphic aspect. Those characteristics includelithotype, type and rank of the coals. The coals formed under wet-swamp condition to result in brighterlithotype and vitrinite-rich coal. By contrast, the coals formed under dry-swamp condition to result induller lithotype and inertinite-rich coal. The Cigudeg coals contain clay minerals and quartz, whilst theBojongmanik coals contain pyrite and calcite. These minerals are beneficial to interpret depositionalenvironment of the coals. Ranks of the Bojongmanik coals are somewhat higher (lignite-subbitumi-nous C-B) that those of the Cigudeg coals (lignite-subbituminous B) according to the ASTM classifi-cation. These higher ranks are due to the thicker overburden on the Bojongmanik coals in terms ofstratigraphic aspect.

Regarding those petrographic characteristics, both coals are suitable for fuel of direct combustion forthe small-scale and home industries that are available in the surrounding areas. Therefore, the coalscan economically cope with the demand of those industries.

Keywords: petrographic analyses, Cigudeg coals, Bojongmanik coals, utilisation

1. INTRODUCTION

Coal deposits are found in many locations in JavaIsland that are distributed from western to easternpart of the island. Resources of the coals are ap-proximately 14,210,000 tons (Hadiyanto, 2006).Most of the coals are located in Banten, and somehave been mined since the Japanese occupationin 1940s, particularly in Bayah Coalfield in south-ern Banten (Sigit, 1980). Unfortunately, researchon coal petrography is rarely carried out in Indo-nesia due to lack of the apparatus facilities andcapability of the human resources. Few coal pe-trologists have been researching for coal in thiscountry since late 1980s, particularly in determiningtype and rank of coal with respect to its utilisation.In addition, some overseas enterprises for oil and

gas exploration have also tried to conduct it since1985, particularly in observing exinite macerals asoil-source rocks (Santoso and Ningrum, 2003).

Cigudeg (Bogor Regency, West Java) andBojongmanik (Lebak Regency, Banten) areas wereselected for the studied areas, because both ar-eas significantly contain six coal seams that weregeologically investigated by Siswoyo and Thayib(1976), Martodjojo (1984), Jusmady (1987) andSantoso and Ningrum (2003). However, these in-vestigations were not supported by coal petrogra-phy and accordingly, the presented data were notcomplete, especially in association with the coalgeological issues. Besides, type and rank of thecoals is unknown that are significant to utilise.

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43Petrographic Analyses of Coal Deposits ... Binarko Santoso and Nining Sudini Ningrum

Regarding the lack of data of coal petrography,attempts have been conducted to contribute andcomplete coal references particularly its utilisationfor small-scale and home industries as fuel of di-rect combustion where the coal is urgently requiredby the industries around the studied areas.

The aims of this study are to obtain an understand-ing of the aspects as follows:

- Analysing type and rank of the Late MioceneCigudeg and Bojongmanik coals of theBojongmanik Formation by making maceralanalyses and reflectance measurements,

- Examiningrelation of type and rank to geologi-cal setting, and

- Examining the implication of the petrographicdata with regard to the utilisation of the coals.

2. METHODS

Thirty coal samples studied were collected fromLate Miocene coals of the Cigudeg (elevensamples) and the Bojongmanik (nineteen samples)areas according to the procedure of the StandardsAssociation of Australia (1964). These sampleswere then examined in reflected white light andreflected ultraviolet light excitation in the labora-tory of coal petrography, Research and Develop-ment Centre for Mineral and Coal Technology,Bandung. Maceral analyses were determined inoil immersion in reflected plane polarised light ata magnification of x500 (Standards Association ofAustralia, 1986). The exinite group of maceralswas accurately studied using ultraviolet light exci-tation at a magnification of x500. An orthoplan mi-croscope fitted with a Leitz Vario-Orthomat cam-era was used for all photography.

Reflectance measurements were conducted us-ing a Leitz Ortholux microscope fitted with a LeitzMPV 1 microphotometer. The microphotometerwas calibrated against synthetic garnet standardsof 0.917% and 1.726% reflectance and a syntheticspinel of 0.413% reflectance (Standards Associa-tion of Australia, 1981).

Normal point count techniques were applied formaceral analysis. The maceral analysis is basedon counting of 500 points using the Swift Auto-matic Point Counter attached to the microscope.The maceral data are calculated as follows:

- mineral matter counted : % vitrinite + liptinite+ inertinite + mineral matter = 100

- mineral matter free basis : % vitrinite + liptinite+ inertinite = 100

After completion of the analysis, maceral group ormineral was expressed as a percentage of the totalpoints recorded. Each point could be examined inreflected white light and fluorescence mode.

Photomicrographs of macerals and mineral mat-ter in the coals were obtained using the Leitz Vario-Orthomat camera.

Reflectance measurements were made on vitrinite,because it undergoes changes consistently withrank Vitrinite shows some inherent variability inreflectance according to type. It is the most abun-dant maceral in most coals and occurs as rela-tively large particles, thereby enabling easy mea-surement. The Standards recommend taking 100measurements to obtain a precise mean value.The result of the measurements is called the meanmaximum vitrinite reflectance.

3. GEOLOGICAL SETTING

Tectonically, Western Java region points the tran-sition between frontal subduction beneathSumatera to the west (Tapponier et al., 1982;Martodjojo, 1989; Keetley et al., 1997). This re-gion has continuously been active since rifting inthe Eocene. The rifting was probably related tothe collision between India and Asia and resultedin a significant influx of coarse clastic sediments.The Oligocene-Recent history is more dominatedby subduction-related volcanism and limestonedeposition. Java Island consists of Seribu Carbon-ate Platform in the north, Rangkasbitung sedimen-tary sub-basin and Bayah High in the south.

The sediments in Banten and West Java comprisenon-marine/continental sedimentary sequencesand marginal marine and marine sedimentary se-quences. Generally, the Tertiary coals are not welldistributed in Java as mentioned by Koesoemadinata,1978). Terrestrial pre-transgressive sedimentationoccurred in West Java only, particularly in south-ern part of Banten and West Java, and resulted incoal deposition within the Bayah (Palaeogene) andBojongmanik (Neogene) Formations. According toRusmana et al. (1982) and Sujatmiko and Santoso

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(1985), Late Miocene Bojongmanik Formationcomprises alternation of sandstone and claystone,limestone and tuff. This formation is divided intothree members, which are Claystone Member withcoal interbed, Limestone Member and SandstoneMember with coal interbed. The formation havinga thickness of 600-800 metres was deposited inshallow neritic-brackish environment in Cigudegand Bojongmanik areas where the sea developedto the west (Darman and Sidi, 2000; Figure 1).Coal deposits are widely distributed in both areasinclude six seams know as seams A to F withinthe Claystone Member (Jusmady, 1987; Figures2 and 3). Thicknesses of the Cigudeg coals vary

BOJONGMANIK CIGUDEG

from 0.2 m to 0.4 m, whilst the Bojongmanik coalsare from 0.15 m to 1.9 m. The Bojongmanik For-mation conformably covers Middle Miocene BaduiFormation at the Bojongmanik area. The BaduiFormation consists mainly of reef limestones.

Structurally, both areas have folding and faultingat the Middle Miocene deposits. The folding haswest-east direction, whilst the faulting, mainlyhorizontal fault, has southwest-northeast direction.In line with the forming of these structures, daciteand andesite intrusions occurred in the easternpart of the Cigudeg area. However, these intru-sions had no contact to the coal seams.

Figure 1. The studied areas at Cigudeg and Bojongmanik (Darman and Sidi, 2000)

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Claystone

Seam A, 0.20 m

Sandstone, claystone

Seam B, 0.20 - 0.24 m

Seam C, 0.24 m

Seam D, 0.20 - 0.40 m

Seam E, 0.20 - 0.30 m

Seam F, 0.20 - 0.30 m

Conglomeratic sandstone, claystone

Claystone

Sandstone

Claystone

Sandstone

Figure 2. The Cigudeg coal seams (not toscale).

Figure 3. The Bojongmanik coal seams(Jusmady, 1987; not to scale)

Claystone

Seam A, 1.00 m

Claystone, sandstone

Seam B, 0.4 m

Claystone, tuff, conglomeratic sandstone

Seam C,1.50 - 2.20 m

Claystone

Seam D, 0.15 - 0.30 mClaystone, tuff, sandstone, limestone

Seam E, 0.50 m

Claystone

Seam F, 0.60 m

Claystone

4. RESULTS AND DISCUSSION

4.1. Results

Megascopically, the Cigudeg and Bojongmanikcoals are dominated by brighter lithotypes, par-ticularly for the Bojongmanik coals (Tables 1 and2). In the Bojongmanik coals, most of the coalseams are bright lithotype with the exception ofseams B and D. Whilst in the Cigudeg coals, thelower seams (D,E and F) are brighter lithotype andthe upper ones (A, B and C) are duller lithotype.

Microscopically, both of the coals are absolutelydominated by vitrinite over inertinite, exinite andmineral matter (Figures 4, 5, 6 and 7).Vitrinitecontent is higher in the lower Cigudeg coals (D, Eand F) than those of the upper ones (A, B and C);whilst in the Bojongmanik coals, its content is highin seams C, E and F.Inertinite content shows rela-tively high in the upper seams (A and B) of theCigudeg coals and seam D of the Bojongmanikcoals.The rest are relatively low in both coals.Exinite content is relatively low in both coals.

Table 1. Cigudeg coals

COAL LITHOTYPE MACERAL (%) MINERAL Rvmax RANKSEAMS (%) V E I (%) (%) Australia ASTM

A 60 DB, 40 DB 69.1 5.6 12.8 12.5 0.2470-0.3255 Brown coal LigniteB 50 BD, 50 DB 67.9 7.6 11.7 12.8 0.2909-0.3376 Brown coal LigniteC 100 DB 79.0 2.6 6.4 12.0 0.2804 Brown coal LigniteD 70 BB, 30 BD 80.1 3.2 7.1 9.6 0.3439-0.3915 Brown coal Lignite-

Subbituminous BE 50 BD, 50 DB 81.9 5.7 7.5 4.9 0.2955-0.3516 Brown coal LigniteF 70 BB, 30 BD 86.6 3.0 5.1 5.3 0.3559-0.3948 Brown coal Lignite-

Subbituminous BNotes: D-dull, DB-dull banded, BD-banded, BB-bright banded, V-vitrinite, E-exinite,

I-inertinite, ASTM-American Standard for Testing Materials

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Table 2. Bojongmanik coals

COAL LITHOTYPE MACERAL (%) MINERAL Rvmax RANKSEAMS (%) V E I (%) (%) Australia ASTM

A 100 B 68.2 10.1 15.7 6.0 0.3721-0.3756 Brown coal Subbituminous CB 50 B, 50 D 55.3 1.1 5.0 38.6 0.3106-0.3312 Brown coal LigniteC 100 B 84.6 3.8 5.1 6.5 0.3721-0.3918 Brown coal Subbituminous C-BD 75 D, 25 B 49.2 2.6 24.1 16.1 0.3027-0.3165 Brown coal LigniteE 100 B 78.0 2.8 5.9 13.3 0.3623-0.3789 Brown coal Subbituminous CF 100 B 74.2 3.4 8.4 14 0.3795 Brown coal Subbituminous B

Notes: D-dull, DB-dull banded, BD-banded, BB-bright banded, B-bright, V-vitrinite, E-exinite,I-inertinite, ASTM-American Standard for Testing Materials

Figure 6. Resinite (black, rounded) associ-ated with telovitrinite (grey),Rvmax=0.36%, field width=0.34mm. Seam D of Cigudeg coals

Figure 4. Vitrinite (grey) and exinite(black), Rvmax=0.65%, fieldwidth=0.28 mm. Seam C ofBojongmanik coals.

Figure 5. As for Figure 4, but in fluores-cence mode

Figure 7. As for Figure 6, but in fluores-cence mode.

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Mineral matter content is mostly high in bothcoals, extremely in seam B of the Bojongmanikcoals that is 38.6% of pyrite and trace calcite.

Vitrinite reflectances of the Cigudeg and Bojongmanikcoals vary from 0.24% to 0.39%. All the coals areranked as brown coal according to the Australianclassification or lignite to subbituminous B(ASTM). Based on the ASTM classification, therank of the Bojongmanik coals is somewhat higherthan that of the Cigudeg coals.

In summary, the vitrinite, inertinite and exinite con-tents of the Cigudeg and Bojongmanik coals aresystematically related to one to another. Theinertinite and exinite contents decrease with in-creases in vitrinite content.Ranks of the coals arerelatively the same, which are brown coal (Austra-lian classification) or lignite to subbituminous C-B(ASTM).

4.2. Discussion

The coal seams of the Bojongmanik Formationare found in the Cigudeg area (eastern part) andthe Bojongmanik area (western part). The Cigudegcoals are associated with thin claystone and sand-stone, whilst the Bojongmanik coals are associ-ated with thick claystone, shale and sandstone.The coals were deposited in shallow neritic-brack-ish environment. The sea developed to the westdue to the presence of thick limestone of theBojongmanik Formation. To the east, its lithologyis dominated by fluvial deposits. The Cigudeg coalshave thicknesses of 0.2-0.4 m, whilst theBojongmanik coals have thicknesses of 0.15-1.9 m.As shown in Tables 1 and 2, lithotypes of theCigudeg coals (eastern part of the studied area)are duller than those of the Bojongmanik coals(western part). This indicates that the Cigudegcoals were formed under dry-swamp. Otherwise,the Bojongmanik coals were deposited in wetswamp due to marine intrusion into the swamp.This is supported by the presence of pyrite andcalcite in the Bojongmanik coals rather than inthe Cigudeg coals that are dominated by clay min-erals and quartz.

Macerals of both coals are dominated by vitriniteover inertinite and exinite.This is indicative of for-est type vegetation in humid tropical zone, with-out significant dry events throughout. Vitrinite-richcoals, particularly in the Bojongmanik coals, havehigh content of mineral matter present as discretedirt bands, due to rapid subsidence (Cook, 1975;

Shibaoka and Smyth, 1975).

Ranks of the coals range from lignite to subbitumi-nous B in which the Bojongmanik coals are some-what higher than the Cigudeg coals due to thickeroverburden on the Bojongmanik coals. This is alsosupported by the calorific value of the Bojongmanikcoals that are relatively higher than that of theCigudeg coals (Santoso and Ningrum, 2003).

According to the type (vitrinite-rich, 49.2-86.6%)and rank (lignite-subbituminous B), the coals arein common suited for direct combustion.However,high moisture contents (18.3-26.3%, air-dried ba-sis; Santoso and Ningrum, 2003) and spontane-ous combustion will cause problems that gener-ally occur in lower rank coal. The vitrinite-rich coalsare suited for preparation in combustion, becausethey are easily ground through to the finer frac-tion. These coals are generally tougher than themore inertinite-rich coals. Resources of the coalsin the studied areas are approximately 14 milliontons (Hadiyanto, 2006). These resources are ex-pected to cope with the coal demand in the areas.Some of the coals have been exploited and utilisedby lime and brick combustion in the surroundingareas. The main utilisation will be for small-scaleand home industries, which are available in thestudied areas with strong demand of the coals.

5. CLOSING REMARKS

The Cigudeg and Bojongmanik coals of theBojongmanik Formation were deposited undershallow neritic-brackish environment where marinedeveloped from east to west. The coals are muchthicker to the west, where the Cigudeg coals (east)are between 0.2 and 0.4 m, whilst the Bojongmanikcoals (west) range from 0.15 to 1.9 m. This envi-ronment caused differences on lithotype, maceraland mineral composition. The Cigudeg coals aredominated by duller lithotypes (dull-banded,banded). On the contrary, the Bojongmanik coalsare dominated by brighter lithotypes (bright).Inertinite contents are somewhat higher in theCigudeg coals than those of the Bojongmanikcoals. Pyrite is dominant in the Bojongmanik coals,whilst clay minerals and quartz are dominant inthe Cigudeg coals.Ranks of the Bojongmanik coalsare higher than those of the Cigudeg coals be-cause of thicker overburden. Both coals arecategorised as low-rank coals due to their lowranks as lignite to subbituminous C and their highmoisture contents.

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According to characteristics of both coals and ur-gent requirement demanded by the small-scaleand home industries around the studied areas, thecoals can be utilised as fuel of direct combustion.Besides their appropriate characteristics, re-sources of the coals can support its demand thatcan be used for relatively long time.

REFERENCES

Cook, A.C., 1975. The spatial and temporal varia-tion of the type and rank of Australian coals.In:Cook, A.C. (editor), Australian black coal-itsoccurrence, mining, preparation and use,Wollongong.

Darman, H. and Sidi, F.H., 2000. An outline of thegeology of Indonesia. Indonesian Associationof Geologists, Jakarta.

Hadiyanto, 2006. Anatomi sumber daya batubaraserta asumsi pemanfaatan untuk PLTU di Indo-nesia. Seminar Nasional Batubara Indonesia.Jakarta.

Jusmady, 1987. Geologi dan endapan batubaradaerah Cimuli-Bojongmanik, KabupatenLebak, Jawa Barat. Thesis. Jurusan TeknikGeologi, Institut Teknologi Bandung, Bandung(tidak dipublikasikan).

Keetley, J.T., Cooper, G.T., Hill, K.C., Kusumabrata,Y., O’Sullivan, P.B. and Saefudin, I.I., 1997.The structural development of the Honje High,Bayah High and adjacent offshore areas, WestJava, Indonesia. In: Howes, J.V.C. and Noble,R.A. (eds.), Proceedings of an international con-ference on petroleum systems of SE Asia andAustralasia. Indonesian Petroleum Association.

Koesoemadinata, R.P., 1978. Sedimentary frame-work of Tertiary coal basins of Indonesia. 3rd

Regional Conference on Geology and MineralResources of SE Asia. Bangkok, Thailand.

Martodjojo, S., 1984. Evolusi Cekungan Bogor.Disertasi Doktor. Jurusan Geologi ITB,Bandung (tidak dipublikasikan).

Martodjojo, S., 1989. Stratigraphic and tectonicbehaviour of the back-arc basin in West Java,Indonesia. Proceedings of 6thregional confer-

ence on geology, mineral, hydrocarbon re-sources, SE Asia (Geoasea VI), Special Pub-lication 106.

Rusmana, E., Suwitidirdjo and Suharsono, 1982.Peta geologi lembar Serang, Jawa Barat.Pusat Penelitian dan Pengembangan Geologi,Bandung.

Santoso, B. and Ningrum, N.S., 2003. Karakteristikbatubara Bojongmanik berdasarkan analisismegaskopis, petrografis dan proksimatnya.Prosiding Kolokium Energi dan Sumber DayaMineral 2003. Puslitbang Teknologi Mineral danBatubara, Bandung.

Shibaoka, M. and Smyth, M., 1975. Coal petrol-ogy and the formation of coal seams in someAustralian sedimentary basins. EconomicGeology 70.

Sigit, S., 1980. Coal development in Indonesia,past performance and future prospects. In:Mangunwijaya, A.S. and Hasan, O. (eds.),Coal Technology. Proceedings of Seminar onCoal Technology and the Indonesian needs.Jakarta.

Siswoyo dan Thayeb, E., 1976. FormasiBojongmanik-suatu satuan litostratigrafi diJawa Barat. Lemigas, Jakarta.

Standards Association of Australia, 1964. Aus-tralian standard code of recommended prac-tice for taking samples from coal seams insitu, AS CK 5. Australia.

Standards Association of Australia, 1981. Micro-scopical determination of the reflectance ofcoal macerals. AS 2486.

Standards Association of Australia, 1986. Coalmaceral analysis. AS 2856.

Sujatmiko and Santoso, S., 1985. Peta geologilembar Leuwidamar, Jawa Barat. PusatPenelitian dan Pengembangan Geologi,Bandung.

Tapponier, P., Peltzer, G., Le Dain, A.Y. andArmijo, R., 1982. Propagating extrusion tec-tonics in Asia: new insights from simple ex-periments with plasticine. Geology, vol. 10.

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A detailed Guide for Authors is available upon re-quest. The authors are kindly asked to consultthis guide. Please note the following notations.

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References. References cited within text start withauthor’s name, followed by publication date in pa-rentheses. The reference list should be ranged inalphabetical order.

1. Book by one and/or more authors

Munitz, M. K., 1974. The Mystery of Existence :An Essay in Philosophical Cosmology, NewYork UP, New York.

Marsden, J., 1992. The Che-mistry of Gold, EllisHarwood, New York.

Danielson, D. F. et al. 1980. Reading English forStudents of English as a Second Language,2nd ed., NJ Prentice, Englewood Cliffs .

2. Edited book and book with introduction,preface, foreword, afterword

Eliot, G., 1961. The Mill on the Floss. Ed. GordonS. Haight, Boston: Houghton.

Barret, M. (ed), 1979. Women and Writing, By Vir-ginia Woolf, Harcourt, New York.

Eble, K., 1964. Introduction, The Awakening, ByKate Chopin, Putnam’s, New York, v – xiv.

3. Periodicals

– Continuous pagination journal

Webb, A. D., 1984. The Science of Making Wine,American Scientist, No. 71, pp. 360 – 7.

– Independent pagination journal

Bianchi, E. C., 1985. Christianity and Violence,Natural Forum, No.63.4, pp. 16 – 7.

– Weekly or biweekly periodical

'A live and well : The Red Brigades are Back' ,Time27 Feb. 1984, no. 46.

4. Speeches

Durant, W. and Durant, A., 1974. Can DemocracySurvive?” Commencement Address Occi-dental College Los Angeles, 8 June.

5. Government Publications

California. Dept. of Alcohol and Drug Programs1980. A Directory of Community Servicesfor Alcohol Abuse and Alcoholism in Cali-fornia, Sacramento : The Department of Al-cohol and Drug Programs, .

Republic of Indonesia, Ministry of Mines andEnergy. Directorate General of Mines. Di-rectorate of Coal 1997, Prodcim-1 1990 -1996, Ministry of Mines and Energy, Jakarta.

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