the effect of leaching behavior of couple nickel cobalt
TRANSCRIPT
The Effect of Leaching Behavior of Couple Nickel – Cobalt Laterite Ore Deposits, Kabaena
Island, Southeast Sulawesi : A Future Prospect of Ni-Co Alkaline Rechargeable Batteries
Ali Reza¹* Rosmalia Dita Nugraheni¹
¹Study Program of Geological Engineering, Faculty of Earth Technology and Energy,
Universitas Trisakti, Jl. Kyai Tapa No.1, Grogol, Jakarta Barat, 1140
ABSTRACT
The increasing demand of nickel makes Indonesia
has received much attention for nickel- laterite ore
deposits. It is because complex geological features
and geographic condition support the development
of nickel laterite. Nickel laterite is commonly
found associate with cobalt that possibly enriched
from the intense leaching of the mafic/ ultramafic
protolith in the regional complex of Southeast
Sulawesi.
In order to fulfil the commodity demand of this
metal exploration needs to be carried out. This
study aimed to decipher the role of intense
chemical weathering and element transport of
Nickel and Cobalt from lateritic deposits. The Ni-
Co enrichment within nickel laterite deposits
presents as a promising resource for further
technology development of Ni-Co alkaline
rechargeable batteries, with regards to its safety,
capacity and environment impact. In order to
accommodate the needs of Ni-Co as electrode
component for batteries, several methods were
carried out to achieve the objectives, such as field
mapping and laboratory analyses comprising of
grain size, petrography and XRF analyses. There
were 81 representative samples were collected
from various bedrocks, saprock and limonitic
zones. The geochemical data of major elements
from XRF analysis comprises of Fe2O3, Cr2O3,
Al2O3, MgO, CaO and SiO2, while trace elements
consist of Ni, Cr and Co. Bulk samples for XRF
were collected from drilling. In order to know the
distribution of Co and Ni, the IDW modelling was
carried out using Surpac software. The results
show that Nickel laterite in Kabaena, Southeast
Sulawesi is derived from ultramafic rocks. This
ultramafic rocks exposed in association with
obducted ophiolite complexes in accretionary belts
of east and southeast Sulawesi. The active tectonic
setting has promoted weathering process and
erosion. Moreover, Southeast Sulawesi which is
situated in equatorial latitude with alternating
warm and humid tropical climate prone to
experience supergene enrichment of Ni and Co.
The enrichment process is also supported by local
landscape that also controls the distribution of ore-
bearing Ni minerals within lateritic regolith.
The vertical profile of laterite deposit from top to
bottom is consisted of iron cap, limonite, saprolite
zone saprock zone and bedrock. The richest Ni
grade range from 1.2 - 2.2 wt% and suspected
occurred when oxide-rich regoliths were uplifted
and Ni leached downwards to concentrate in neo-
formed silicate in the saprolite. On the contrary,
the riches Co concentration ranges from 0,1 – 0,16
wt % and observed within limonitic zone. Most of
Co are incorporated into Fe- hydroxide minerals as
well as secondary clays found in limonitic zone,
such as geothite, hematite and smectite. For IDW
modelling, several value of Ni- cut off grade were
mapped and compared with the distribution model
of cobalt. At cut-off grade of 1.8% nickel and
0.07% Cobalt
INTRODUCTION
This research on The Effect of Leaching Behavior
of Couple Nickel - Cobalt Laterite Ore Deposits is
to obtain geochemical data on laterite nickel
deposits on the island of West Kabaena, Southeast
Sulawesi. The problems studied are related to
petrology, geomorphology, geochemistry which
are also processed into ore deposit modeling with a
predetermined cut-off grade.
This paper presents a discussion of petrology and
the quantity of the main elements in laterite nickel
deposits and their relationship with ore bearing
minerals and how the effects of the elemental
enrichment process in geochemistry lead to
differentiation of laterite profiles on the island of
Kabaena, Southeast Sulawesi. The research is
located in IUP PT Timah Investasi Mineral on
Kabaena Island, Bombana Regency, Southeast
Sulawesi Province with a research area of 300
hectares. Located on the geological map sheet
Kolaka, Sulawesi by T.O Simandjuntak, Surono
and Sukido (1993).
REGIONAL GEOLOGY
Regionally the research area is in the mandala of
East Sulawesi which is characterized by ultramafic,
mafic, and Metaporhic rocks. basalt, metamorphed
mafic and magnetite, thought to be Cretaceous,
these rocks are the host of nickel mineralization and
its associations. Metaporhic rocks of the
Pompangeo complex consist of various types of
schist and debris sediments as well as serpentinite
and glaucofan schists. These rocks are thought to
have formed in the Benioff subduction strip at the
end of the Early Cretaceous to the Paleogene
(Simanjuntak, 1980, 1986). The ultramafic rocks
and the rocks of the Pompangeo Complex are
related by tectonic contact.
Structure
The collision of the continental strip with Ophiolite
which caused the disclosure of the ultramafic
complex in the study area, the collision occurred
after the youngest rock on the continental chip and
ophiolite, but not younger than the cretaceous era -
early Oligocene, while the youngest rock on the
southeastern Sulawesi continental shelf was an
oligocene carbonate rock. The possible location of
the collision between the continental strip and the
ophiolite occurred at a location that is not at its
present location. Surono drr (1997). Due to oblique
collisions which caused large continental pieces of
sula proud to split into smaller parts and scatter over
the eastern and southeastern parts of Sulawesi along
with the exposed ultramafic complex.
There is a local structure in the research area,
Sungkup faults on Kabaena Island. This fault is
trending almost west-east covering the Ultramafik
Complex over the Pompangeo Complex and the
Metamorphic Kabaena sediments, thought to have
occurred in the Mesozoic era.
Mineralization
The mineralization found in this area is: laterite -
nickel. Nickel laterites are often found in the
investigation area, especially the P. Kabaena area
which is included in the District. Bombana (T.O.
Simandjuntak, et al, 1994)
METHODS
Field geological mapping on Kabaena island was
conducted during early to late august 2020 to
characterize each formations from two observation
locations composed by 13 outcrop stations. The
sampling method were used to observe the profile
section from each outcrop stations. There 81
samples collected from all lithologies and analyzed
in the laboratory with XRF analysis and
petrography analysis to determine mineral and rock
type and geochemical behavior of nickel laterite
deposit.
Figure 2. Map of Outcrop Stations
Figure 1. Geological Map Of Sulawesi (Hall and Wilson, 2000)
RESULTS
Geomorphology
The classification of landscapes (geomorphology)
in this research area refers to the van Zuidam
classification (1983), which is divided into 2 (two)
geomorophological units (Figure 2.), the structural
corrugated hilly morphological unit and the
structural sloping hilly geomorphological unit. In
the slope analysis based on topographic maps using
ArcGis software, the slope classification is divided
into 4 groups (Figure 3), namely 0-8%, 9-15%, 16-
25%, and 26-45%. The landscape in the study area
has a higher elevation in the eastern part with an
elevation of 45m-60m and in the western part it has
a lower elevation with an elevation of 35-40m.
Figure 4 Slope Map of Research Area
Nickel laterite profile and geochemical behavior
In general, the exposed rocks in the research area
are laterite products from the ultramafic complex
with profiles starting from the top, namely Iron
Cap, Red Limonite, Yellow Limonite, Saprolite,
Saprock and Bedrock (Figure 6). Rock outcrops can
be observed on the mine peel walls. Ultramafic rock
as a source rock in fresh condition is found on river
walls
Figure 5 Nickel Laterit Profil in research area (LP 1) with a model laterit profil (M. Ellias,2002)
Ferricrete
The hardening of regolith is noticeable from the
part of the section sampled at LP 1,8,12 up to the
terrane surface, highlighting the apical zone of
ferricrete or laterite residue. In regard to the
geochemical signature, this zone represents the
most enriched in immobile elements. with the
highest Fe oxi-hydroxides account for 45-58% at
LP 8 and 12. Co is also increased by 5 times.
Nevertheless, the most outstanding enrichment is
that shown by Cr attaining 2.3 wt.% on elemental
basis. Furthermore, Ni grades at this zone are rather
low (in the order of 0.5 wt.%)
Limonit
The limonite profile in the study area is at the top
of the profile below the top soil. In general, it can
be divided into two based on color appearance,
namely Red limonite and yellow limonite. In
Figure 3. Geomorphology Map of Research Area (Van Zuidam, 1983)
general, limonite has a silt-clay grain size. Red
limonite is megascopically distinguished by its red
appearance. Oxidizing features are also often found
in iron-rich minerals such as hematite, goethite and
chromium. In yellow limonite, iron-rich minerals
are less common.
The limonite zone in a laterite nickel deposit profile
generally contains elements that are insoluble by
water, the compounds are non-mobile which are
relatively high which allows them to be insoluble
by water in the weathering process. From the results
of chemical analysis based on core data, chemical
content parameters of Fe2O3, SiO2, MgO and Ni
are used. The content of Fe2O3 compounds
contained in the limonite zone has a relatively
higher percentage of content between the saprolite
and bedrock zones with 35-45% Fe2O3 content,
inversely proportional to the elemental content of
MgO, in the limonite zone the MgO content has a
lower percentage. Ni content is also relatively less
with an average level (0.7-1.2%). The highest
enrichment process is at Co with levels 0.05-0.3%.
Geochemical analysis using Ternary Weathering
Diagram of nickel laterit shows that this source rock
is a lithiophorite profil. (Figure 6)
Saprolit
In the saprolite profile in the eastern part of the
study which has a higher elevation, it has a layered
appearance between medium sand and
conglomerate sand. It has a greenish brown color
with the appearance of conglomerates (fragment
size 0.5-5cm medium sand matrix) monomic
fragments with different degrees of weathering and
oxidized subrounded grain shape, poor sorting,
poor compactness open packing. In this profile,
many silica boxwork textures are found. In the
western part of the study area with a lower elevation
saprolites have rougher physical properties with
larger fragments measuring 5-15cm.
In the petrography analysis of sandstone samples
from laterite profiles, the dominant mineral is clay
minerals with an abundance of 43% and then filled
with 30% volcanic glass, 10% quartz, 8% opaque
minerals, 5% Feldspar and 4% ortho pyroxene.
(Figure 7)
Saprolite zone in a laterite nickel deposit profile
generally contains elements that are soluble by
water, the compounds are relatively high in mobile
properties which allow them to be easily dissolved
by water in the weathering process. Ni has the
highest enrichment in the saprolite zone with levels
of 1.3-2.1%, Fe2O3 levels have lower levels than
limonite and fericrete zones with levels of 14-20%
as well as Cr2O3 0.6-1.4%, SiO2 37-45%. Cao and
MgO in the saprolite zone had higher levels than the
limonite zone, namely 0.6-1.4% CrO and 14-17.5%
MgO. Co in the saprolite zone has lower levels,
namely 0.01-0.03%
Figure 8 Limonit samples plot on ternary diagram of nickel laterite
Figure 6 Limonit samples plot on ternary diagram of nickel laterite
Figure 7 Thin section of sandstone from saprolit profil (LP 1)
Saprock
Saprock zones with a lower level of Ultramafic
weathering, so that it still leaves a hard original rock
component. At the boundary between fragments /
fragment fractures, there is the mineral garnierite to
fill the muscular space. The presence of the mineral
garnierite will increase the nickel content because
garnierite contains more nickel than saprolite itself.
The fragments in the saprock zone have gravel to
lump sizes of 5-50cm in size.
Figure 9 Thin section of Fragmet from saprock profil (LP 8)
The fragments in saprock are greenish in color with
a size of 5-50cm, poor sorting, sub-angular grain
shape, medium cohesiveness, the main mineral is
garnierite. Petrography analysis (Figure 9) on the
fragments showed serpentine fragments with
different degrees of weathering.
The saprock zone in the laterite nickel deposit
profile on the island of Kabaena has a Ni content of
1.2-2.27%. This high level shows physical
characteristics in the form of the presence of nickel-
bearing garnierite minerals. Minerals carrying iron
are relatively less with 11-17% Fe2O3, 0.84-1.2%
Cr2O3. while MgO has levels of 20-28% and SiO2
ranges from 35-55%. The cobalt content is also
relatively very low 0.02-0.03%.
Bedrock
The bedrock zone in a laterite profile generally
contains chemical elements which are inherited
from the source rock. The source rock in the study
area is a complex of ultramafic rock. Megascopic
appearance (Figure 10,11), This rock has a black-
green color (mafic) with a faneric, holocrystalline
texture, euhedral crystal shape and consists of a
dominant mineral composition of pyroxene and
appears to be mica minerals, in some parts it
appears to have been serpentinized with a soapy
feel. In the petrography observation (Figure 12),
there was the appearance of dominant serpentine
minerals by 80% and clino-pyroxene minerals by
20%. This parent rock is a serpentinized peridotite.
In the geochemical data analysis, Ni content ranged
from 0.2-0.8% with 10-25% Fe203, 2-4% Al2O3,
and 0.5-1% Cr2O3. MgO as an immobile element
is at the highest level in this laterite profile ranging
from 18-33% and Cao 0.5-1.5%. Geochemical
analysis using Ternary Weathering Diagram of
Mafic Rock shows that this source rock is in Un-
altered (Un-Wethered) condition. (Figure 12)
Figure 11 Ultramafic Outcrop at Lp 10 as a bedrock in nickel laterite deposit in Kabaena Island
Figure 10 Ultramafic Outcrop at Lp 10 as a bedrock in nickel laterite deposit in Kabaena Island
Figure 12 Ternary Weathering Diagram of Mafic Rock (after Nesbitt and Wilson, 1992)
Figure 13 Geochemical Ni-Co-Cr2O3-Cao analysis
Figure 104 Geochemical Fe2O3-SiO2-Al2O3 analysis
Modelling
Modeling of laterite nickel deposits was carried
out using Surpac 6.3 software and using the IDW
method for estimation. Modeling is conduct using
over 180 drillhole data (figure 14). Based on the
geological modeling of the Limonite and Saprolite
profiles, it can be seen that the formation of laterite
deposits is strongly influenced by topography and
slope(figure 15). In areas with steeper slopes,
laterite profiles are more actively formed, and in
relatively sloping areas a limonite profile is
dominantly formed.
Figure 115 Borehole Map of research area
Figure 126 Geology model of limonit and saprolit area
carried out using IDW method
Nickel ore modeling was carried out with cut-off
grades 1.2, 1.5 and 1.8 (figure 16,17,18). The
distribution of nickel ore was dominant in the
saprolite profile. Meanwhile, cobalt modeling with
a cut-off grade of 0.07 (Figure 19) appears to be
predominantly scattered in the limonite profile
Figure 137 Ni block modelling , Cutoff grade 1.2%
Figure 148 Ni block modelling , Cutoff grade 1.5%
Figure 15 Co block modelling , Cutoff grade 0.7%
ACKNOWLEDGEMENTS
The authors want to express their thanks to all the
family in geological department Trisakti
Univeristy and PT. Timah Investasi Mineral which
have given attention and support the author to
conduct geological field Research. Special thanks
to Mrs. Rosmalia Dita and Mr. Budi Wijaya whom
always provided moral support to finish the study
activity.
CONCLUSION
The geological study of the study area comprised
of geomorphological analysis where the study area
is the Exhibited Structural area with various
slopes. The stratigraphic analysis in the research
area which is an ultramafic rock complex in the
form of peridotite is formed by the presence of
large tectonic activity in the form of obduction of
the oceanic plate against the Sulawesi mandala,
thus exposing ultra mafic rocks on the island of
Kabaena. Due to the presence of ultramafic rocks
and the occurrence of the laterization process, the
island of Kabaena has the potential for interesting
laterite nickel deposits.
Geochemical analysis of laterite nickel deposits
shows that there are different characterizations in
each laterite nickel deposit profile, this happens
because of the supergene enrichment process
which is influenced by the mobility of each
element associated with the mineral ore bearing.
The potential for nickel elements associated with
garnierite minerals is in the saprolite and saprock
profiles (1.2-2.2%), while the highest potential for
the presence of cobalt is in the limonite profile
(0.5-3%). In the analysis of nickel deposit
modeling based on drill point data, it can be seen
that the distribution of laterite nickel deposits is
strongly influenced by topography which has an
impact on the laterization process.
REFERENCES
Ibrahim, M. A., Rustandi, U., Suryana, A., 2014,
Penyelidikan Bitumen Padat Daerah Pulau
Kabaena Kabupaten Bombana, Provinsi Sulawesi
Tenggara. Proceedings Geological Resource
Center.
Simandjuntak, T.O., Surono, and Sukido, 1993,
Geological Map sheet of Kolaka, Sulawesi,
1:250.000, Geological Research and Development
Centre, Bandung.
Streckeisen, A. L., 1976, Classification of The
Common Igneous Rocks by Means of Their
Chemical Composition: A Provisional Attempt.
Neues Jahrbuch fur Mineralogie, Monatshefte,
1976, H.l, 1-15.
Gabriel Aragão Rodrigues Soares., Nely Palermo,
Fernando Roberto Mendes Pires, 2018,
Geochemical and mineralogical characterization of
a section through the nickeliferous laterite in
Fazenda da Roseta, Liberdade, Minas Gerais,
Brazil, Universidade do Estado do Rio de Janeiro.
Charles R. M. Butt., Dominique Cluze., 2013,
Nickel Laterite Ore Deposits: Weathered
Serpentinites, ELEMENTS, VOL. 9, PP. 123–128
Manuel Muñoz, Marc Ulrich, Michel Cathelineau,
Olivier Mathon , Weathering processes and crystal
chemistry of Ni-bearing minerals in saprock
horizons of New Caledonia ophiolite. Gexplo
(2018).,https://doi.org/10.1016/j.gexplo.2018.12.0
07
Armstrong F. Sompotan, 2012, Struktur Geologi
Sulawesi, Institut Teknologi Bandung
Hall, R. & Wilson, M. E. J., 2000, Neogene sutures
in eastern Indonesia. Journal of Asian Earth
Sciences
M. Elias.,2000, Nickel laterite deposits – geological
overview, resources and exploitation., Mick Elias
Associates, CSA Australia
C. R. M. BUTT, R. C. MORRIS, 2005., Ore-
Forming Processes Related to Lateritic Weathering,
©2005 Society of Economic Geologists, Inc.
Economic Geology 100th Anniversary Volume pp.
681–722
A. Isjudarto., 2013, PENGARUH MORFOLOGI LOKAL TERHADAP PEMBENTUKAN NIKEL LATERIT, SEMINAR NASIONAL ke 8 Tahun 2013 : Rekayasa Teknologi Industri dan Informasi