Laterite Samples Research Articles

Macromechanics, microstructure and particle contact model of artificially cemented laterite

In this paper, the research is based on iron hydroxide colloids that combine loose kaolin clay media to form artificial laterite samples. A method and device for the preparation of colloids have been developed. The compressive strength test method is used to explore the regularity and mechanism of free iron oxides which in the process of the formation and strength increase of laterite structure. X-ray diffraction (XRD), scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR) were used to study the mineral composition of the laterite, the cementation of microscopic aggregates of the particles, and the changes in the internal porosity of the laterite. The results show that the free iron oxide can improve the macro-mechanical properties of laterite. The iron morphology has a tendency to change from colloid to hematite and goethite. It is found that the free iron oxide aggregated in the space or on the surface of clay particles. Distribution; gel particles were found to fill the pores of laterite particles or aggregates by nuclear magnetic resonance experiments, indicating that the changes in the mechanical strength of laterite are mainly due to the content of free iron oxide, the formation of free iron oxide, the connection of cementing iron and the distribution of iron. Based on the SEM results, a contact model of laterite particles that can reflect the macro-mechanical failure behavior of soil samples is established.

Effect of Alkali Seepage Erosion on Physical and Mechanical Properties of Laterite

Using a modified permeameter, laterite samples that were corroded and permeated by alkaline solutions at different concentrations for varying amounts of time were subjected to triaxial compression tests, chemical composition analysis, particle composition tests, and microstructure analysis. The results showed that the strength parameters c, φ, and K of the laterite samples that were corroded by alkaline‐solution permeation were reduced with increasing corrosion time and alkaline‐solution concentration. The alkaline‐solution corrosion had a minor effect on the strength parameters n and Rf. The contents of Al2O3 and Fe2O3 in the laterite fluctuated and decreased with increasing alkaline‐solution concentration and corrosion time. There were no distinct patterns in the relationships between the SiO2 content and the increases in the alkaline‐solution concentration and corrosion time. Due to the corrosion during the alkaline‐solution permeation, the content of clay particles increased with increasing time and concentration of the alkaline solution. After the permeation with the alkaline solution, the soil particles became smaller and were arranged in an ordered state. The analysis suggested that the permeation effect of the alkaline solution changed the chemical composition of the laterite and the connecting strength of the soil particles, resulting in changes in its physical and mechanical properties.

Restricted Effect of Two Plant Root Systems on the Crack Expansion of China Yunnan Laterite under Dry-wet Cycle

In order to research the restricted effect of hedera nepalensis root systems and heteropogon contortus root systems on the crack expansion of Yunnan laterite under dry-wet cycle, this paper prepares Yunnan laterite with certain moisture content, and makes the compacted samples of pure laterite and composite soil mixed with root systems by adopting hedera nepalensis root systems and heteropogon contortus root systems respectively, and then simulates the dry-wet cycle of laterite in engineering (i.e., rainfalls and evaporations), measures the crack width of samples experiencing different cycles, and makes statistical analysis on the average maximum crack width of samples in all groups by adopting the method of indoor spraying and natural drying. The result indicates that, 10% and 20% mixed hedera nepalensis root systems can exert obvious restrictions on the crack expansion of Yunnan laterite after dry-wet cycle, while 30% mixed hedera nepalensis root systems and 10% mixed heteropogon contortus root systems can also restrict the crack expansion of Yunnan laterite, but the restricted effect is weaker. As for 20% and 30% mixed heteropogon contortus root systems, composite soil samples will disintegrate after the 2nd dry-wet cycle.

Model of the Evolution of the Modulus of Elasticity E, As A Function of the Bearing Capacity Index ICBR of Gravelly Laterites. Case of the Banka Locality (Westcameroon)

The objective of this study is to model the evolution of the values of the modulus of elasticity E as a function of the bearing capacity index ICBR of Banka lateritic gravel, with the aim of reducing the cost and time of laboratory tests for the determination of the modulus of elasticity and the CBR index. Geotechnical identification tests were carried out on 18 laterite samples taken from the Banfeko, Bakoye and Ketcho sites in the Banka locality. ICBR values ranged from 31 to 51.92 and E-modulus values ranged from 80 MPa to 165 MPa. The resulting model is polynomial for all sites of the form: E = a* ICBR 5 + b* ICBR 4 + c* ICBR 3 + d* ICBR 2 + e* ICBR +f This model has the highest degree of interdependence of value 1.

SUGARCANE STRAW ASH EFFECTS ON LIME STABILIZED LATERITIC SOIL FOR STRUCTURAL WORKS

The research examined the appropriateness of sugarcane straw ash (SSA) as a modifier in lime stabilized lateritic soil with a view of improving the Geotechnical considerations of the soil structures. Elementary and Geotechnical investigations were performed on the lime stabilized soil samples and also when varying percentages of SSA were introduced. The elementary tests incorporated the moisture content, specific gravity, molecule size examination, and Atterberg's limits, while the Geotechnical were: compaction, California Bearing Ratio (CBR), and unconfined compression test. The lateritic samples were stabilized with 7% optimum of lime by weight, while SSA contents were gradually introduced at optimum lime up to 12.5% bulk of the soil. The addition of the SSA to the lime stabilized lateritic soil diminished the plastic indices from 25.09 to 21.98%, 24.76 to 21.09% and 19.43 to 15.37%; increased the unsoaked CBR values from 6 to 12%, 6 to 10% and 8 to 10 % and the unconfined compressive strengths from 88.10 to 126.13 kPa, 73.8 to 114.1 kPa and 52.17 to 127.85 kPa for tests A, B and C respectively. Concluding, the expansion of sugarcane straw debris improved the Geotechnical considerations of the lime stabilized lateritic soil tests for structural works.

Evaluation of selectivity of sequential extraction procedure applied to REE speciation in laterite

Rare earth elements (REE) speciation in laterites are commonly estimated from sequential extraction procedure (SEP). In this study, the selectivity of a 5-steps SEP protocol was evaluated on individual synthetic Ce-material and applied to a well-characterized lateritic profile developing over a granite bedrock (Madagascar). The synthetic Ce-materials are representative of laterite minerals: Ce-doped oxyhydroxides and kaolinite, cerianite, Ce-rhabdophane and Ce-bastnäsite. The morphology, specific surface area, Ce sorption concentrations were thoroughly characterized prior to SEP. X-Ray absorption spectroscopy on synthetic material indicates that Ce(III) dominates apart for cerianite and Mn-oxide. The evaluation of the 5-steps SEP scheme shows that reagent selectivity is generally good, but the use of hydroxylamine hydrochloride is strongly discouraged. First, distinction between Ce sorbed at the surface of Mn- and amorphous or crystalline Fe-oxyhydroxides remains ambiguous. Second, Ce-rhabdophane (phosphate) and Ce-bastnäsite (carbonate) dissolve partially with this reagent. These experimental results combined with previous mineralogical and geochemical characterization were fundamental to interpret SEP results in the laterite profile from Madagascar. In the three laterite samples from the A-, B- and C-horizons, it is proposed that REE mainly distribute in authigenic phosphates and Fe- and (Mn-)oxyhydroxides. In the oxidized B-horizon, there is a significant LREE/HREE and Ce(IV)/Ce(III) fractionation between laterite minerals. While LREE-Ce is mainly concentrated in phosphates (alunite-jarosite supergroup), it is proposed that HREE and Ce(IV) uptake is dominated by oxyhydroxides. In the A- and C-horizons, the LREE and HREE speciations are similar, indicating no significant LREE/HREE fractionation in laterite minerals and organic matter. In all horizons, the REE ion exchangeable is negligible, although kaolinite is a main mineral of the A- and B-horizons.

Effects of chemical solutions on the hydromechanical behavior of a laterite/bentonite mixture used as an engineered barrier

Compacted laterite and bentonite, as well as a mixture of the two, are strongly impermeable and can effectively prevent the migration and diffusion of contaminants. This study explored the feasibility of employing a laterite/bentonite mixture as a vertical barrier in landfills, tailings ponds, or sites contaminated by heavy metals. Permeability tests using chemical solutions of different concentrations and compression tests were performed on mixed bentonite/laterite samples with different dry densities and mixing ratios. The permeability and consolidation characteristics were verified using scanning electron microscopy. The hydraulic conductivity of the laterite samples decreased with increased dry density, and the hydraulic conductivity of the mixed-soil samples decreased with increased bentonite content. Adding bentonite significantly improved seepage control performance. The hydraulic conductivity of the pure laterite was 4.7 × 10−7 cm/s, whereas that of the laterite sample mixed with 20% bentonite was 1.6 × 10−8 cm/s. The compacted laterite with a dry density of 1.5 g/cm3 was demonstrated to satisfy the permeability specifications to serve as a landfill seepage control system. When the concentration of the heavy metal or salt solutions increased, the laterite flocculation increased, and the hydraulic conductivity decreased. The laterite in the mixed soil samples substantially affected these characteristics, particularly decreasing the hydraulic conductivity. As the concentration of the chemical solutions increased, the yield stress of the compacted samples and the compression index decreased, and the compression performance improved. These findings indicate that chemical solutions significantly affect the hydromechanical behavior of a laterite/bentonite mixture used as an engineered barrier.

Compressive strength and water absorption of cement stabilized earth brick mixed with locust bean pod extract

This study presents the experimental investigation carried out on the compressive strength and water absorption properties of lateritic blocks stabilized with cement and locust bean pod extract. Tests were carried out in which different sample batches of cement blocks (0.1, 0.2, 0.3, 0.4 and 0.5kg) were moulded and different sample batches of locust bean pod extract blocks (50, 100, 133, 150 and 200g/litre) were moulded and with both cement and locust bean pod moulded too. The compressive strength of the lateritic block samples were tested at 28 days. The results indicated that the cement with locust bean pod extract significantly increase the compressive strength of the lateritic block samples. This compressive strength increases as the amount of cement and locust bean pod extract was increased. This is a validation of the high possibilities of both cement locust bean pod extract being utilized as a binder in the production of blocks for low housing construction in developing areas of Nigeria.Â

Efficacy of Class C Fly Ash as a Stabilizer for Marginal Residual Soil

Two laterites samples known for their deficiency in road construction were used to assess the efficacy of Class C fly ash in improving their engineering properties. The two samples were taken from Danbare and Dausayi localities within Kano Metropolis and the fly ash was sourced from the Nigerian Coal Corporation, Enugu. Preliminary tests on the two samples confirmed their deficiency for use in road construction. The processed fly ash was blended with the laterite samples at 0, 3, 6, 9, 12, 15 and 18%. Hence, the treated soil samples were tested for plasticity, compaction and strength properties. Results obtained revealed reduction in plasticity properties as the fly ash contents increased. Similarly, Maximum Dry Density (MDD) decreased as the fly ash content increased while the Optimum Moisture Content (OMC) of the treated soils increased for the two samples. Peak CBR values of 16 and 35% were obtained at 9 and 15% fly ash contents for samples 1 and 2, respectively. The unconfined compression tests showed considerable improvement in strength properties higher than the values of the natural soils. The peak 7 days strength of 630 and 1410 kN/m2 were observed at 12% and 15% fly ash content for samples 1 and 2, respectively.

Effects of Low-Density Polyethylene (LDPE) Strips on Some Engineering Properties of Cement-Stabilized Lateritic Soils

The study investigated the compaction and strength characteristics of lateritic soils stabilized with 3% cement and waste sachet water-proof (low-density polyethylene, LDPE) strips. Three (3) lateritic samples collected from Ugwuoba, Nawfia, and Okpuno in Enugu and Anambra states of Nigeria were used in the study. Index properties tests on the samples show that they fall within class A-2-6(1) and A-2-4(0) based on the American Association of State Highway and Transportation Officials (AASHTO) and SM/SC based on Unified Soil Classification System (USCS). LDPE strips were varied at 0, 0.25, 0.5, 0.75, 1, 1.5, and 2% based on the dry unit weight of the soil. Results of unconfined compressive strength (UCS) tests show significant improvement in the strength of the soils at 2 % LDPE strips. Statistical analysis also shows that a significant relationship exists between the percentage of LDPE strips, compactive effort, and maximum dry unit weight (MDUW)/optimum moisture content (OMC), UCS of the soils. The tensile and flexural strength of lateritic soil stabilized with 3% cement can be improved optimally by the addition of 2% of low-cost LDPE strips of aspect ratio (AR) of 10 mm  10 mm.

Evaluation of Strength Properties of Subgrade Materials Stabilized with Bio-Enzyme

In the recent studies many chemical have been emerged and used as stabilizing agent. One of such chemical (Bio-enzyme) was used in this study as a stabilizing agent. Bio-enzyme is prepared locally from fermented vegetable and fruits waste. These products are natural, nontoxic, non-corrosive, nonflammable liquid and environmentally harmless. In this research, Bio-enzyme was prepared and used in varying proportion to stabilize laterite samples collected from different locations. Detailed laboratory experiments (Classification tests and CBR) were conducted to evaluate the effects of Bio-enzyme at varying dosage after 24 hours of curing of specimens. The percentage passing through sieve No. 200(75 micron) was less than 35%., according to ASHTO and clause 6201 of Federal Ministry of Works and Housing (F.M.W & H) Specification Requirements, sample A is (A-2-5), sample B is (A-2-4) while sample C is classified as A-2-6 and they are silty or clayed gravel and sand. Sample A is a good subgrade, subbase or base materials based on highest CBR values (at 20% bio-enzyme dosage, Sample A (102.50%) and sample B (69.40%) & at 10% sample C (33.2%). Sample B can also be used as subgrade or subbase materials where light traffic is considered and sample C is suitable as filling materials as evident in their CBR value. It has been observed that Bio-enzyme treated soil shows significant improvement in terms of the dry density and CBR value. Presence of Bio-enzyme in the soil samples led to increase in the C.B.R by 10-20% as compared to the control). However, it is recommended that assumption should not be made that Bio-enzyme is considered suitable for all type of soil and long term effect of it should also be examined.

Evaluation of Strength Properties of Subgrade Materials Stabilized with Bio-Enzyme

In the recent studies many chemical have been emerged and used as stabilizing agent. One of such chemical (Bio-enzyme) was used in this study as a stabilizing agent. Bio-enzyme is prepared locally from fermented vegetable and fruits waste. These products are natural, nontoxic, non-corrosive, nonflammable liquid and environmentally harmless. In this research, Bio-enzyme was prepared and used in varying proportion to stabilize laterite samples collected from different locations. Detailed laboratory experiments (Classification tests and CBR) were conducted to evaluate the effects of Bio-enzyme at varying dosage after 24 hours of curing of specimens. The percentage passing through sieve No. 200(75 micron) was less than 35%., according to ASHTO and clause 6201 of Federal Ministry of Works and Housing (F.M.W & H) Specification Requirements, sample A is (A-2-5), sample B is (A-2-4) while sample C is classified as A-2-6 and they are silty or clayed gravel and sand. Sample A is a good subgrade, subbase or base materials based on highest CBR values (at 20% bio-enzyme dosage, Sample A (102.50%) and sample B (69.40%) & at 10% sample C (33.2%). Sample B can also be used as subgrade or subbase materials where light traffic is considered and sample C is suitable as filling materials as evident in their CBR value. It has been observed that Bio-enzyme treated soil shows significant improvement in terms of the dry density and CBR value. Presence of Bio-enzyme in the soil samples led to increase in the C.B.R by 10-20% as compared to the control). However, it is recommended that assumption should not be made that Bio-enzyme is considered suitable for all type of soil and long term effect of it should also be examined.

Trace and REE geochemistry of bauxite deposit of Darai–Daldali plateau, Kabirdham district, Chhattisgarh, India

The Darai–Daldali plateau preserves well developed laterite type bauxite deposits as a result of in-situ weathering of basaltic rocks (Deccan Traps). The bauxite ore is essentially composed of gibbsite and boehmite in subordinate amount, along with anatase and brookite as accessory minerals. Kaolinite, goethite, hematite, ilmenite, gibbsite and brookite are found in lateritic bauxite and laterite samples in variable amounts. SiO2–Al2O3–Fe2O3 diagram illustrates strong bauxitization resulting from desilication in the early stage. The disilication was followed by bauxitization and deferruginization at late stages as a result of reducing and oxidizing conditions, respectively, due to fluctuating water table, which is evidently supported by A–L–F plot. Progressive loss/gain in FMTE, LILE, HFSE and REE during bauxitization process of basalt through lateritic bauxite facies is observed. La/Y varying from 1.17 to 4.11 suggests prevalence of alkaline conditions. Positive Eu/Eu* anomaly in these samples is suggestive of colloidal precipitation of gibbsite from pore water of lateritic residuum. Mass increase of Ce in laterite samples further supports to its sorption on goethite and hematite mineral phases.

Influence of hydrated lime and bitumen on different lateritic soil samples: case study of Sheda-Abuja, Nigeria

This research was performed so as to appraise strength and properties of lateritic soils enriched with hydrated lime and bitumen as construction materials. Soil samplings S1, S2, S3, S4, and S5 was collected from Dualization of Sheda - Abaji, Abuja, F.C.T, Ni-geria and augment with 0, 3, 6, 9, and 12% of hydrated lime and bitumen. Laboratory tests like Consistency (Atterberg limit), California Bearing Ratio (C.B.R), compaction and sieve scrutiny were done on the soil sampling. The study exposed that construc-tive effects were gotten via the addition of hydrated lime and bitumen in order to augment the strength of weak soils. All the 5 samplings have C.B.R values of 48.0% with hydrated lime as additives, whereas bitumen additive is 40.60%. Introduction of addi-tives enriched the soil samplings from weak materials to an excellent base material with C.B.R values above 40%. Hence, aug-mentation of lateritic soil samplings from the studied locality could be perform efficiently by using lime. Â

Assessment of Quality of Some Laterites in Northeastern Nigeria by Multivariate Analysis of their Geotechnical Index Properties

The index properties of lateritic soils derived from sandstone, limestone, gneiss, granite, basalt, and migmatite in northeastern Nigeria were assessed for selecting the type with the best engineering potentials. The laboratory test results indicate that the tested samples comprised predominantly sand-sized particles (58–88%), with clay fraction (2–12%) of low to moderate plasticity (liquid limit, LL 35–49 and plasticity index, PI 12–24). Other geotechnical properties are as follows: natural water content (Wn), specific gravity (SG) 2.51–2.68, maximum dry density (MDD) 1.69–2.05 mg/m3, and unconfined compressive strength (UCS) 20–43 kPa. Principal component analysis reveals three significant factors. The first factor has loadings from clay, LL, PI, Wn, and SG, indicating impacts that are mineralogical and particulate constituent related. The second has loadings from gravel, MDD, and UCS and indicates textural influence, while the third factor has loadings from silt and sand, thus, reveals textural impact. The analysis of variance result reveals a significant difference in dataset, while cluster analysis indicates three different sample clusters, with a granite laterite sample representing the central object of the first cluster and sandstone and limestone laterite samples representing central objects of the second and third clusters, respectively. Comparatively, the second cluster samples would likely perform best in engineering projects having recorded comparatively the least clay content, lower plasticity, highest SG, MDD, and UCS. Thus, a combination of index properties and multivariate analysis proves a useful tool in the geotechnical prospecting for lateritic soils.

Dissolution optimization and kinetics of nickel and cobalt from iron‐rich laterite ore, using sulfuric acid at atmospheric pressure

AbstractMore than 70% of the world's nickel reserves are found in laterite ores. In this research, a laterite ore sample, containing Ni, Co, and Fe, was employed to study the recovery of nickel and cobalt. Thus, the effect of calcination, acid concentration, percent solids, and stirring rate on nickel and cobalt recoveries from an iron‐rich laterite sample was investigated. Optimization with response surface methodology and kinetic studies were performed. The calcination of the sample prior to leaching at 500°C for 2 h provided condition for better nickel and cobalt dissolutions. At optimal conditions, the concentration of sulfuric acid, solid‐to‐liquid ratio, stirring speed, temperature, and time test were equal to 5 M, 0.1, 370 rpm, 90°C, and 2 h, respectively. The highest recoveries of nickel and cobalt were 65.9% and 63.1%, respectively. Solids content had a negative effect on Ni and Co recovery, whereas acid concentration was positively affected. Addition of 10% (w/v) NaCl in the presence of 5 M acid concentration, 60°C, 370 rpm, and leaching time of 2 h increased the nickel and cobalt recoveries, 15.3% and 21.4%, respectively. The high dependence of process on temperature indicates chemical control; the activation energies Ea = 59.54 and Ea = 45.74 kJ/mol, respectively, for nickel and cobalt, were also consistent with this conclusion.

OPTIMUM PERFORMANCE OF STABILIZED EDE LATERITE AS AN ALTERNATIVE CONSTRUCTION MATERIAL

Laterite samples from Ede area with particle components of 19.7% clay, 32.8% silt and 47.5% sand was stabilized with combined cement, lime and bitumen and test for Compressive strength, Linear Shrinkage, Permeability and Water Absorption. The stabilizers were mixed with laterite soil in different ratios and percentage. The laterite carried 90% which is constant while the three stabilizers shared the remaining 10% in varying form. After 28 days of curing, laterite stabilizer with 90% of laterite, 8% of cement, 1% lime and 1% bitumen (LCLB1) possessed compressive strength of 2.01N/mm2. It Water Absorption Capacity was 3.05%. LCLB4 stabilizer (90% laterite, 6% cement, 2% lime and 2% bitumen) has the same compressive strength with LCLB1 stabilizer but with a high Water Absorption Capacity of 4.2%. The stabilizer of 90% laterite, 3.33% cement, 3.33% lime and 3.33% of bitumen (LCLB8) has the lowest compressive strength of 0.74N/mm2 and the highest Water Absorption Capacity of 5.39%. The results shows that LCLB1 stabilizer is a better stabilizer for strength and blocks made from laterite stabilized with it stand a good alternative to sand Crete blocks in building constructions. The combination of these stabilizers in order to determine a most economical volume combination for optimum performance is highly possible and economical.

Use of Alternative Binder: Influence of Latex Content on Physical and Mechanical Properties of Laterite Stabilized with Raw Rubber Latex

Raw rubber Latex contents, from 0% to 30% were used to stabilize lateritic samples to provide an alternative to cement stabilization. These samples were submitted to physical tests (water resistance test, absorption test) and mechanical tests (dry compressive strength test). The results indicate that samples made of latex content less than 15% dissolve completely into water. So it was impossible to make sample with these contents. Samples with 15% of raw rubber content or more are steady after water resistance test. The absorption rate of these samples decreases as the latex content increases. It goes from 14.45% for the samples at 15% to 5.87% for those at 30%. Therefore, the compressive strength test indicates that the resistance increases from 0.37 MPa for samples without latex to 3.15 MPa for those at 30% of latex content. Also, the rheological study shows that the samples pass from a brittle behaviour to a plastic behaviour when the latex content increases. The behaviour of the sample according to these different tests shows that this material can be used in several activity areas, such as construction, road building and sports area.

Performance analysis of cement-stabilised laterite for road construction in the tropics

Unstabilised laterite has been reported to be an unsuitable base course material under tropical environmental conditions. This research considered the suitability of three cement types for laterite stabilisation to achieve optimal performance as a base course material. Cement samples investigated were Dangote 3X, Supaset and Powermax. A-5(4) and A-5(12) lateritic soil samples classified according to the American Association of State Highway and Transportation Officials classification are commonly found in tropical regions. Performances were considered at different cement–laterite proportions, varying from 2 to 14%. The parameters calculated included maximum dry density (M DD), California bearing ratio (C BR), unconfined compressive strength (U CS), hydraulic conductivity k and optimum moisture content (O MC). The A-5(12) laterite sample was found to contain 45·7% silicon dioxide (SiO2) and 32·56% aluminium oxide (Al2O3), while the A-5(4) laterite sample had 44·24% silicon dioxide and 30·35% aluminium oxide. The results also indicate that M DD, C BR and U CS increased as the cement content increased, while O MC reduced as the cement content increased for all three cement types. The hydraulic conductivity analysis indicates that the hydraulic conductivity reduced as the cement content increased. In general, results from this investigation appear to indicate that Supaset cement is the most suitable for achieving optimal strength and hydraulic performance for laterite samples under tropical environmental conditions.

Study on Sc-bearing Lateritic Ni deposits in Ultramafic Rock from Sulawesi: A New Paradigm in Indonesia Metal Mining Industry

Scandium (Sc) and its compounds are used in many modern-technology applications such as in optical, electronic, aeronautical, and fuel-cell industries. However, Sc occurrence were only limited in a very specific area with limited deposit and little attention has been paid to the genesis of Sc-bearing deposits in the world. 6 (six) bedrock samples and 15 (fifteen) lateritic samples (saprolite to limonite) were collected and studied to investigate the distribution of Sc grades in lateritic Ni deposits and identify Sc-bearing minerals in laterites from ultramafic rocks in West Blok, East Block and Petea prospect in Soroako, South Sulawesi, Indonesia. The study suggests that scandium is enriched in limonite layer in weathering profile. In general, pyroxene bearing rich bedrock (harzburgite in composition) will contain higher Sc content in their weathering product. It is suggested that the Sc are associated with the occurrence of iron oxide from pyroxene. However, as the occurrence of Sc is very limited, the most promising result was shown by East Block profile in which the enrichment of Sc is also supported by enrichment of NiO content. Sc will be viable as by-product of nickel laterite.