the hwange coal deposit - fossil fuel · hwange sandstone black shale and coal group upper hwange...

THE HWANGE COAL DEPOSIT

INTRODUCTION

¥ The economic development of a Nation is directlyproportional to the production and utilisation ofenergy, particularly electricity.

¥ Like the rest of the SADC countries, Zimbabwe hasgreat potential for growth.

¥ Endowed with huge fossil fuel resources of world classquality, Zimbabwe fossil fuel remains and will for along time be a major source of energy to the Nationand the region.

2

INTRODUCTION (CONT.)

¥ For a period spanning almost 110 years, the Hwangecoal deposit has been the sole source of coal in theCountry.

¥ Coal from this fossil fuel deposit played a vital role inboth world wars by supplying the needs of the BritishGovernment/Army.

¥ The role of this coal deposit has remained key inSouthern Africa. Thermal power generation inZimbabwe is based at Hwange.

3

“DISCOVERY” OF THE HWANGE COAL DEPOSIT

4

EXPLORATION HISTORY

¥ Exploration activity commenced withthe arrival in Hwange of Albert Giese, aGerman geologist, in 1892.

¥ He registered the first claims in 1893which he sold to Mashonaland Agency.

¥ In 1895 he pegged 400 sq miles onbehalf of Mashonaland Agency.

¥ Wankie Rhodesia subsequentlyacquired the claims and sank 15exploratory shafts.

5

¥ The Main incline shaft of what became No.1 Colliery was completed in 1902.

6 EXPLORATION HISTORY (CONT.)

LOCATION

¥ The Hwange Town is situated in the north-westerncorner of Zimbabwe (see map below)

¥ Hwange Coal Basin is bounded by longitudes 260 15’and 260 30’ east and latitudes 180 20’ and 180 30’south (see map below)

7

LOCATION (CONT.)8

HWANGE

ACCESSIBILITY

¥ Hwange Town is situated 335km and 100km by roadfrom Bulawayo and Victoria Falls, respectively.

¥ The Bulawayo to Victoria Falls Railway Line passesthrough Hwange Town.

¥ Victoria Falls Airport is approximately 80km away andHwange town itself has a surfaced airstrip.

9

KAROO BASINS IN ZIMBABWE10

Upper Sengwa Basin

Gwayi Basin

Mlibizi Basin

Lower Sengwa Basin

REGIONAL GEOLOGY

¥ The Hwange Coal Basin is a western extension of theMulibizi intra-basin (the latter is part of ZambeziBasin).

¥ It bifurcates into Entuba-Lukosi to the South andHwange and Western Areas coalfields to the North.

11

HWANGE CONCESSION AND SURROUNDING COALFIELDS

12

MID ZAMBEZI BASIN COALFIELDS & COAL

OCCURENCES13

REGIONAL CORRELATION

¥ The coal measures within the Mid-Zambezi Basin arecorrelatable (see Schematic below).

¥ In all coalfields the basal seam is the only viable one(known by local names e.g Bira Seam and HwangeMain Seam for Lubimbi and Hwange, respectively).

14

15

MOLTENO

BEAUFORT

ECCA

DWYKA

LOWER KAROO IN THE MID-ZAMBEZI BASIN (ZIMBABWE)

LUBIMBI LUSULU BUSI - SENGWA KAONGA SANYATI

UPPER KAROO

Tillite

Lower Hwange Sandstone

Black Shale and Coal Group

Upper Hwange Sandstone

Madumabisa Mudstones

Sidaga Mudstone

Hankano Beds

Clay -Ranch

Formation

Ridge Sandstone

Tshale Formation

Waterfall Sandstone

Bira Coal Measures

Lubimbi Glacials

Upper Sandstone

Upper Coal-ShaleCentral

Sandstone

Lower Coal-Shale

Lower Sandstone

Deweras Wacke

Tillites and

Varvites

K0

K1

K2

K4

K5T

K5R

K5C

K5H

K5d+e

K5c

K5b

+

K5a

K5d

K5c

K5b

+

K5a

Schematic columnar sections of key areas and their lithostratigraphic correlation (Adopted from J. Lepper)

HWANGE

not to scale

16

GEOLOGICAL MAP OF HWANGE COALFIELD

GEOLOGICAL PROCEDURES

¥ Geological mapping (surface andunderground)

¥ Diamond core drilling

¥ Database processing for seammodelling and resource / reserve andquality computation

17

GEOLOGICAL SAMPLING AND DATABASE

¥ Diamond core drilling executed on standard 300m grid

¥ Coal horizon samples taken at 1.0 m intervals incarbonaceous mudstones and 0.5m intervals in thecommercial coal horizon

¥ Samples analysed for moisture, ash, volatiles,phosphorus, sulphur and swelling index

18

DRILLHOLE DATABASE

a) Sample Analysis

Data resides in the “raw table”and

Comprises:

¥ Borehole number

¥ Sample id

¥ Depth range (from– to--)

¥ Analyses – ash, volatile, phos, and sulph

19

DRILLHOLE DATABASE (CONT.)

b) Lithology

Data resides the “geology table” and comprises ten “fields” as follows:

Hole id Sample id

Depth from Depth to

Colour Grain Size

Jointing Weathering

Rock type Description

20

Height above footwall (m)

Sample Length (m)

Moisture (%) Ash (%)

Volatile (%)

Phosphorus (%) Sulphur (%)

Swelling Index

0.53 0.53 1.7 14.5 23.6 0.042 2.13 1.01.03 0.50 1.5 10.3 24.4 0.014 2.04 1.01.53 0.50 1.9 13.6 22.1 0.009 2.08 1.02.03 0.50 1.2 12.4 24.6 0.013 1.62 1.02.53 0.50 1.4 12.1 22.7 0.009 1.44 1.03.03 0.50 0.9 21.6 20.8 0.020 3.12 0.53.53 0.50 1.4 17.4 20.8 0.010 1.72 1.04.03 0.50 1.0 17.5 21.3 0.015 1.38 1.04.53 0.50 1.2 24.1 17.9 0.023 1.67 0.55.03 0.50 1.4 15.7 18.7 0.057 1.19 0.55.53 0.50 1.1 25.5 18.2 0.055 2.70 0.06.03 0.50 1.3 19.3 18.3 0.053 0.90 0.56.53 0.50 1.3 22.9 18.1 0.230 1.33 0.57.03 0.50 0.9 26.4 19.0 0.211 1.11 07.53 0.50 1.5 28.5 16.3 0.040 0.50 08.03 0.50 1.2 37.4 14.2 0.024 0.38 08.53 0.50 1.8 26.2 16.5 0.024 0.36 09.03 0.50 0.8 30.9 19.9 0.039 0.34 09.74 0.71 0.6 26.1 23.4 0.156 0.48 0

10.53 0.79 0.6 51.6 15.0 0.103 0.27 011.53 1.00 0.9 56.3 14.8 0.121 0.32 012.53 1.00 1.0 46.3 16.8 0.149 0.42 013.53 1.00 0.7 73.7 13.6 0.072 0.19 014.53 1.00 1.1 66.4 12.9 0.687 0.23 015.53 1.00 1.2 56.3 16.5 0.092 0.45 016.53 1.00 0.7 56.2 16.0 0.188 0.55 017.53 1.00 0.7 64.2 15.0 0.100 0.25 018.53 1.00 0.8 58.3 14.8 0.112 0.39 019.53 1.00 1.0 52.9 15.8 0.224 0.53 020.53 1.00 0.8 52.7 15.6 0.052 1.38 0

RAW ANALYSIS OF BH579521

TYPCIAL SEAM ATTRIBUTES (HWANGE SEAM)

¥ Vertical variation in physical and chemical parameters:

Ø Ash and phoshorus contents increase with distanceabove footwall

Ø Volatile and sulphur contents decrease with distanceabove footwall

¥ Vertical variation in maceral constitution:

Ø Reactive macerals (vitrinite) at seam base

Ø Inert macerals towards hangingwall.

22

COAL SEAM MODELLING (HWANGE COAL DEPOSIT)23

Compositing Diagram Moving Mean ASH from footwall

Moving Mean ASH from top of HCC

Moving Mean VM from footwall

Moving Mean VM from top of HCC

VM ASH23.5%

0 15% 24%

HCC

HPS

1 : HCC VM Cut - Off

2 : HCC ASH Cut - Off

3 :HPS ASH Cut - Off

1

2

3

Bor

ehol

e Tr

ace

HPS = Thermal CoalHCC = Coking Coal

HWANGE MAIN SEAM

CARBONACEOUS MUDSTONES

HPS (Thermal Coal)

MAX. 24% ASH

HCC (Coking Coal)

MAX. 15% ASH

MIN. 23.5% VOLATILES

FOOTWALL

INC

REA

SE IN

VO

LATI

LE &

SU

LPH

UR

CO

NTE

NT

INC

REA

SE IN

ASH

&

PHO

SPH

OR

US

CO

NTE

NT

24

THERMAL COAL

¥ The definition of thermal coal varies, depending onthe designs of the respective targeted Thermal PowerPlants:

Ø South Africa - Ash up to 35% and CV ranges from 21 to24 Mj/kg.

Ø Zimbabwe - Ash up to 25% and CV of 24 to 26 Mj/kg.

¥ Zimbabwe is under utilising its coal (discarding aswaste what could be Power Coal).

25

COKING COAL

¥ Cumulative Ash maximum of 15% and cumulativeVolatile minimum content of 23.5%.

¥ Swelling Index ranging from 1.5 to 8.0 (based on thestandard ash and volatile cut-offs).

¥ Reactive macerals range of 40% to 60% according tolocation and height above footwall.

¥ Typical specifications shown below.

26

TYPICAL METALLURGICAL COAL SPECIFICATIONS

A. CHEMICAL PROPERTIES (RESULTS ON AIR DRIED BASIS)

% COMPOSITION

Inherent Moisture 0.8

Ash 9.8

Volatile Matter 23.4

Fixed Carbon 64.0

Volatile Matter (daf) 26.3

Sulphur 1.3

Free Swelling Index 2.0

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Calorific Value = 29.8Mj/kg

TYPICAL METALLURGICAL COAL SPECIFICATIONS

B. ASH % COMPOSITIONSilica (SiO) 47.3

Alumina (Al2O

3) 35.5

Iron Oxide (Fe2O

3) 1.8

Titanium Oxide (TiO2) 1.2

Calcium (CaO) 2.7

Magnesium (MgO) 0.5

Sodium Oxide (Na2O) 0.9

Potassium Oxide (K2O) 1.0

Phosphorus Oxide, Sulphur trioxide etc

1.2

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High silica levels (>50%) lead to low furnace productivity. Ideally, maximum silica levels should be in the range 40%-45%.

PETROGRAPHIC PROPERTIES

C. MACERALS ANALYSIS % COMPOSITIONREACTIVESVitrinite % 34.1

Liptinite (Exinite)% 0.6

Reactive Semifusinite% 8

Total Reactives % 42.7

INERTSInert Semifusinite% 11.9

Micrinite% 0.9

Macrinite% 14.3

Inertodetrinite% 8.9

Fusinite + Secretinite% 16.1

Minerals(Calculated) % 5.2

Total Inerts % 57.3

29

PRODUCTION HISTORY

30

PRE-INDEPENDENCE

¥ Production commenced at No.1 Colliery in 1902.

¥ Coal was initially transported by ox wagon.

31

PRE-INDEPENDENCE (CONT.)

¥ Rail line from Bulawayo reached Hwange in 1903,enabling the Company to supply coal at agreedquantity, quality and price to mines, railways andindustry.

32

PRE-INDEPENDENCE (CONT.)

¥ Mining was essentially by the underground bord andpillar hand-got system.

¥ Opencast mining was intermittent and limited to smallpits to supplement underground mining operationsduring periods of increased coal demand.

¥ Increased demand led to the Company commissioningNo.2 and No.3 Collieries in 1927 and 1953,respectively.

33

PRE-INDEPENDENCE (CONT.)

¥ No.1 Colliery decommissioned in 1961 following thecommissioning of Kariba Hydro Power Plant.

¥ Regrettably a major disaster occurred at No.2 Shaft inJune 1972, and the shaft was closed.

¥ To make up for the lost coal production, No.4 Shaft wascommissioned in 1976.

34

POST- INDEPENDENCE

¥ Two major developments took place soon afterindependence:

a) Completion and commissioning of the 950MWHwange coal-powered station on the HwangeCoalfield; and

35

POST- INDEPENDENCE (CONT)

b) The commissioning of the MainOpencast Mine which employed the“Dragline with SupplementaryStripping Method” to supply the newThermal Plant with coal.

36

POST-INDEPENDENCE(CONT.)

¥ Subsequently the manual underground miningmethod was replaced initially by the semi-mechanisedmethod when the LHD replaced the shovel andwheelbarrow for coal tramming in the late 1990’s atthe No.3 Colliery.

37

POST-INDEPENDENCE(CONT.)

¥ A fully mechanised bord and pillar mining method wasadopted in 1998 by the introduction of a miningequipment suite comprising a Continuous Miner,three Shuttle Cars and a mechanical Roof bolter.

38

POST-INDEPENDENCE(CONT.)

¥ Production increased reaching a peak of 5.915 milliontonnes total coal per year in 1991.

¥ Since then and up to 2009 production has been on adownward trend due mainly to national economicchallenges.

¥ From 2010 production has been on an upturn due tovigorous re-capitalisation efforts (see graph below).

39

¥ Subsequently more shafts (collieries) were developed.

40PRE-INDEPENDENCE

(CONT.)

PRODUCTION HISTORY

-

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,00019

8019

8119

8219

8319

8419

8519

8619

8719

8819

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

9920

0020

0120

0220

0320

0420

0520

0620

0720

0820

0920

1020

11

ANN

UAL

TO

NN

AGE

(ton

nes)

YEAR

RAW COAL PRODUCTION 1980 - 2011

41

MINING TECHNIQUES

42

MINING METHODS

¥ Choice of methods depends on depth of coal from surface:

Ø Opencast strip mining 0 – 70m depth

Ø Underground bord and pillar > 70m and up to 360m

43

44

THE OPENCAST PROCESS FLOW

45

UNDERGROUND MINING OPERATIONS

ENABLERS

46

TRANSPORT

¥ Both rail and roadconnect the coalfield tomajor centres in thecountry. See map

47

ELECTRIC POWER

¥ The Hwange coaldeposit isconnected to theprimary powertransmissionsystem.

48

Chakari

WATER SUPPLY

¥ Coal mining requires large amounts of water, affectsnatural water systems and hence calls for a balance ofthe two systems.

¥ The coalfield draws its water from the Zambezi Riverby pipe line (44km long) and from deep boreholes(200m) located along the Deka Fault.

49

SKILLS & LABOUR

¥ Sound human skills base and high literacy rate in thework force. Generally peaceful workforce despitehaving labour laws skewed towards labour.

50

CHALLENGES

51

LOCATION IN RELATION TO MARKETS

¥ Coal deposit in theextreme west, whilemarket is in the easternpart of the country.

¥ Off-shore exports viaMozambique and SA (seeinset table for distances)

52

Centre Rail Distances (km)

Beira Maputo Durban Richards Bay

Gweru 869 967 1,764 1,684

Bulawayo 1,051 1,083 1,880 1,800

Hwange 1,389 1,421 2,218 2,138

Mutare 290 1,546 2,641 2,561

Beitbridge 1,333 745 1,598 1,518

Chicualacuala 1,300 536 1,879 1,799

CHALLENGES (CONT.)

¥ High ash and sulphur contents.

¥ Environmental concerns (sitting in main water basin).

¥ Skills flights are still a big challenge.

¥ Policies and practices on the coal exploitation, especiallyat the exploration stage, not yet very clear and veryexpensive.

¥ New Minerals and Environmental Acts underformulation.

53

CHALLENGES (CONT.)

¥ Coal Mining Policy Framework weak (skills, minedesign/practices and resource definition)

¥ Current procedure to exploit a new mining concessioninvolves the following 3 stages:

SG à EIA à Mine Site Plan

54

MARKETS

55

COAL MARKETS

¥ The Hwange coal deposit supplies approx. 80 – 85% ofthe Zimbabwean market with most of it coming fromthe Hwange Colliery Operations.

¥ The average distribution pattern by sector is as shownin the table below.

56

SECTOR MONTLY TONNAGE(tpm)

Industry 120,000

Agriculture 10,000

Mines 50,000

Power 200,000

TOTAL 380,000

COAL MARKETS (CONT.)

¥ Currently the Zimbabwean market is subdued againsta background of increasing new entrants into the coalmining industry. This scenario could lead to a demiseof the coal sector.

¥ External markets have to date been limited toCountries of the sub-region (Zambia, DRC & SouthAfrica).

57

COAL MARKETS (CONT.)

¥ Opportunities are available in the off-shore markets(India, China).

¥ Zimbabwe’s cost of production and transport ishowever not internationally bench-marked but it ishigher than regional benchmarks. This is largely aresult of the National Economic Challenges. Thesituation has to change positively if Zimbabwean coalis to be competitively placed on the InternationalMarket.

58

CONCLUSION

¥ The Hwange District is well endowed with a world classcoal deposit of thermal, industrial and coking coal.

¥ Exploitation of the deposit is supported by the requisiteinfrastructure.

¥ Due to the current subdued nature of the local marketagainst an increase in the number of coal producingcompanies HCCL is now looking at penetrating the off-shore markets.

¥ There is growing demand for coking coal internationally.

59

CONCLUSION (CONT.)

¥ Zimbabwe is landlocked and long distances to the seaports for export markets affect landed prices. RegionalRails are expensive and Governments need to resolvethis issue.

¥ The anticipated economic growth in Zimbabwe willincrease demand for energy thereby offeringopportunities in Power Generation.

60

THANK YOU