A New On-Line Method for Predicting Iron Ore Pellet Quality

The Abrasion Index (AI) describes fines generation from iron ore pellets, and is one of the most common indicators of pellet quality. In a typical pellet plant, dust is generated during the process and then captured. Can the dust be measured and used to predict AI? In this paper, the feasibility of using airborne dust measurements as an indicator of AI is investigated through laboratory tests and using data from a pellet plant. Bentonite clay, polyacrylamide and pregelled cornstarch contents, and induration temperature were adjusted to control the abrasion resistance of laboratory iron ore pellets. AI were observed to range from approximately 1% to 12%. Size distributions of the abrasion progeny were measured and used to estimate quantities of PM₁₀ (particulate matter with aerodynamic diameter less than 10 µm) produced during abrasion. A very good correlation between AI and PM₁₀ (R² = 0.90) was observed using the laboratory pellets. Similarly, a correlation was observed between AI and PM measured in the screening chimney at a straight-grate pelletization plant in Brazil, with an R² value of 0.65. Thus, the laboratory and industry data suggest that measuring dust generation from fired pellets may be an effective on-line measurement of pellet quality. The data also showed that particulate emissions from pelletization plants may be directly affected by AI.     

Iron Ore Pellet Dustiness Part I: Factors Affecting Dust Generation

Iron ore pellets abrade during handling and produce dust. This study was conducted to determine what factors affect pellet dustiness, and whether dustiness can be related to the abrasion index. Factors studied included bed depth within a straight grate furnace; pellet chemistry; firing temperature; coke breeze addition; and tumble index. Abrasion indices for all pellet samples ranged from 1.9–5.0% (20 samples) and from 7.1–27.5% (5 samples). Pellets were dropped in an enclosed tower, which enabled the collection of airborne particles generated during pellet breakdown. The quantity of airborne particles generated by each pellet type was 10–100 mg/kg-drop, or 50–500 mg/kg over five drops through the tower. Pellet dustiness was predominantly affected by pellet chemistry and by pellet firing temperature. Results showed a nearly 21% increase in dustiness for every percent decrease in firing temperature – this was based on a typical firing temperature of 1280°C. Pellet dustiness was regressed to the pellet abrasion index (for AI < 5%), which yielded a correlation coefficient of 0.22. These results show that, although AI is one of the best indicators of fired pellet quality and can indicate high levels of dust, it could not explain the dustiness of good quality pellets.

The second paper (Iron Ore Pellet Dustiness Part II) explains the relationship between AI and dust for good-quality pellets; and compares fines generation between pellets fired in Straight-Grate (Traveling Grate) and Grate-Kiln furnaces.     

Diffusion of hydrogen in iron

A mass spectrometer was used to study hydrogen diffusion and trapping phenomena in fullyannealed and slightly cold-worked pure iron specimens which were in contact with distilled water or dilute acidic Buffer solutions. In the case of fully-annealed iron and slightly coldworked iron, hydrogen can diffuse into iron only when the iron contacts water directly. This diffusion phenomenon of hydrogen increased markedly with temperature and was accelerated by abrasion and hydrogen ion concentration in dilute acid. Abrasion and hydrogen ions in a dilute acidic Buffer solution did not affect the diffusion coefficient of hydrogen,D, but increased the hydrogen concentration at the iron surface contacting water or Buffer solution,C _s . The permeability of hydrogen in fully-annealed iron in contact with distilled water and the diffusion coefficient of hydrogen in fully-annealed and slightly cold-worked iron for the temperature range 10° to 100°C were measured. Trapping parameters in the slightly cold-worked iron were calculated.     

Thermogravimetric Analysis and Kinetics on Reducing Low-Grade Manganese Dioxide Ore by Biomass

Nonisothermal thermogravimetric analysis (TGA) was applied to evaluate rice straw, sawdust, wheat stalk, maize straw, and bamboo to explore their potential for reduction of manganese dioxide ore. Results from the biomass pyrolysis experiments showed that wood-based biomass materials, such as sawdust and bamboo, could produce more reductive agents, while herb-based biomass materials, such as rice straw, wheat stalk, and maize straw, had lower reaction temperatures. The peak temperatures for biomass reduction tests were 20 K to 50 K (20 °C to 50 °C) higher compared with the pyrolysis tests, and a clear shoulder at around 523 K (250 °C) could be observed. The effects of heating rate, biomass/manganese dioxide ore ratio, and different components of biomass were also investigated. An independent parallel first-order reaction kinetic model was used to calculate the values of activation energy and frequency factor for biomass pyrolysis and reduction of manganese dioxide ore. For better understanding the reduction process, kinetic parameters of independent behavior of manganese dioxide ore were also calculated by simple mathematical treatment. Finally, the isokinetic temperature T _i and the rate constant k ₀ for reduction of manganese oxide ore by reductive volatiles of biomass were derived according to the Arrhenius equation, which were determined to be 603 K (330 °C) and 108.99 min^?1, respectively.     

Features of reduction of high-magnesia nickel ore of the serov deposit

Parameters of reducing the roasting of high-magnesia oxide nickel ore containing, wt %, 1.2 Ni, 0.026 Co, 17.0 Fe₂O₃, 4.0 Al₂O₃, 20.2 MgO, and 46.0 SiO₂ are evaluated. The degrees of reduction and metallization upon heating the ore with the reducing agent in the range t = 800−1250°C and the sizes of metallic inclusions forming in the course of the process are determined. To separate the phases, the magnetic separation of reducing products at H = 40 and 80 kA/m is used. The best characteristics are attained upon roasting the ore with a reducing agent and a sulfidizing agent at t = 1300°C. In this case, the magnetic fraction contains 7.1% Ni, while the nonmagnetic one contains 0.18% Ni.     

Upgrading Titanium Ore Through Selective Chlorination Using Calcium Chloride

To develop a simple and effective process for upgrading low-grade titanium ore (ilmenite, mainly FeTiO₃), a new selective chlorination process based on the use of calcium chloride (CaCl₂) as the chlorine source was investigated in this study. Titanium ore and a titanium ore/CaCl₂ mixture were placed in two separate crucibles inside a gas-tight quartz tube that was then positioned in a horizontal furnace. In the experiments, the titanium ore in the two crucibles reacted with either HCl produced from CaCl₂ or CaCl₂ itself at 1100 K (827 °C), leading to the selective removal of the iron present in the titanium ore as iron chlorides [FeCl _x (l,g) (x = 2, 3)]. Various kinds of titanium ores produced in different countries were used as feedstock, and the influence of the particle size and atmosphere on the selective chlorination was investigated. Under certain conditions, titanium dioxide (TiO₂) with purity of about 97 pct was directly obtained in a single step from titanium ore containing 51 pct TiO₂. Thus, selective chlorination is a feasible method for producing high purity titanium dioxide from low-grade titanium ore.     

Preparation of Aluminum Metal Matrix Composite with Novel In situ Ceramic Composite Particulates, Developed from Waste Colliery Shale Material

A novel method is adapted to prepare an in situ ceramic composite from waste colliery shale (CS) material. Heat treatment of the shale material, in a plasma reactor and/or in a high temperature furnace at 1673 K (1400 °C) under high vacuum (10^?6 Torr), has enabled in situ conversion of SiO₂ to SiC in the vicinity of carbon and Al₂O₃ present in the shale material. The composite has the chemical constituents, SiC-Al₂O₃-C, as established by XRD/EDX analysis. Particle sizes of the composite range between 50 nm and 200 μm. The shape of the particles vary, presumably rod to spherical shape, distributed preferably in the region of grain boundaries. The CS composite so produced is added to aluminum melt to produce Al-CS composite (12 vol. pct). For comparison of properties, the aluminum metal matrix composite (AMCs) is made with Al₂O₃ particulates (15 vol. pct) with size <200 μm. The heat-treated Al-CS composite has shown better mechanical properties compared to the Al-Al₂O₃ composite. The ductility and toughness of the Al-CS composite are greater than that of the Al-Al₂O₃ composite. Fractographs revealed fine sheared dimples in the Al-CS composite, whereas the same of the Al-Al₂O₃ composite showed an appearance of cleavage-type facets. Abrasion and frictional behavior of both the composites have been compared. The findings lead to the conclusion that the in situ composite developed from the colliery shale waste material has a good future for its use in AMCs.     

Utilization of Coke Oven Gas and Converter Gas in the Direct Reduction of Lump Iron Ore

The application of off-gases from the integrated steel plant for the direct reduction of lump iron ore could decrease not only the total production cost but also the energy consumption and CO₂ emissions. The current study investigates the efficiency of reformed coke oven gas (RCOG), original coke oven gas (OCOG), and coke oven gas/basic oxygen furnace gas mixtures (RCOG/BOFG and OCOG/BOFG) in the direct reduction of lump iron ore. The results were compared to that of reformed natural gas (RNG), which is already applied in the commercial direct reduction processes. The reduction of lump ore was carried out at temperatures in the range of 1073 K to 1323 K (800 °C to 1050 °C) to simulate the reduction zone in direct reduction processes. Reflected light microscopy, scanning electron microscopy, and X-ray diffraction analysis were used to characterize the microstructure and the developed phases in the original and reduced lump iron ore. The rate-controlling mechanism of the reduced lump ore was predicted from the calculation of apparent activation energy and the examination of microstructure. At 1073 K to 1323 K (800 °C to 1050 °C), the reduction rate of lump ore was the highest in RCOG followed by OCOG. The reduction rate was found to decrease in the order RCOG > OCOG > RNG > OCOG-BOF > RCOG-BOFG at temperatures 1173 K to 1323 K (900 °C to 1050 °C). The developed fayalite (Fe₂SiO₄), which resulted from the reaction between wüstite and silica, had a significant effect on the reduction process. The reduction rate was increased as H₂ content in the applied gas mixtures increased. The rate-determining step was mainly interfacial chemical reaction with limitation by gaseous diffusion at both initial (20 pct reduction) and moderate (60 pct reduction) stages of reduction. The solid-state diffusion mechanism affected the reduction rate only at moderate stages of reduction.     

Effect of Microwave Treatment Upon Processing Oolitic High Phosphorus Iron Ore for Phosphorus Removal

Influence of microwave treatment on the previously proposed phosphorus removal process of oolitic high phosphorus iron ore (gaseous reduction followed by melting separation) has been studied. Microwave treatment was carried out using a high-temperature microwave reactor (Model: MS-WH). Untreated ore fines and microwaved ore fines were then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and thermogravimetric analysis (TGA). Thereafter, experiments on the proposed phosphorus removal process were conducted to examine the effect of microwave treatment. Results show that microwave treatment could change the microstructure of the ore fines and has an intensification effect on its gaseous reduction by reducing gas internal resistance, increasing chemical reaction rate and postponing the occurrence of sintering. Results of gaseous reduction tests using tubular furnace indicate both microwave treatment and high reduction temperature high as 1273 K (1000 °C) are needed to totally break down the dense oolite and metallization rate of the ore fines treated using microwave power of 450 W could reach 90 pct under 1273 K (1000 °C) and for 2 hours. Results of melting separation tests of the reduced ore fines with a metallization rate of 90 pct show that, in addition to the melting conditions in our previous studies, introducing 3 pct Na₂CO₃ to the highly reduced ore fines is necessary, and metal recovery rate and phosphorus content of metal could reach 83 pct and 0.31 mass pct, respectively.     

Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe₂O₃-84.40, Fe (total)-59.02, Al₂O₃-7.18, and SiO₂-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment. It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.     

Study on Phosphorus Removal of High-Phosphorus Oolitic Hematite by Coal-Based Direct Reduction and Magnetic Separation

In this article, mineralogical phase changes and structural changes of iron oxides and phosphorus-bearing minerals during the direct reduction roasting process were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). It has been found that the reduction of hematite follows the following general pathway: Fe₂O₃ → Fe₃O₄ → FeO → Fe. The last step of the reduction process contains two side reactions: either FeO → Fe₂SiO₄ → Fe or FeO → FeAl₂O₄ → Fe depending on the micro mineralogical makeup of the ore. In the reduction process of FeO → Fe, oolitic structure was destroyed completely and fluorapatite was diffused into gangue while metallic phase is coarsening at temperatures below 1200°C. Therefore, the separation of phosphorus-bearing gangue and metallic iron can be achieved by wet grinding and magnetic separation, and low phosphorus content metallic iron powder can be obtained. However, when the temperature reached 1250°C and beyond, some of the fluorapatite was reduced to elemental P and diffused into the metallic iron phase, making the P content higher in the metallic iron powder.     

Crystallization of Phase-Separated Pd41.25Ni41.25P17.5 BMGs

Phase-separated Pd_41.25Ni_41.25P_17.5 bulk metallic glasses (BMGs) were subjected to isothermal annealing at 613 K (340 °C) for different time periods, t, in the range of 0 ≤ t ≤ 8 hours. For 0 ≤ t ? 5 hours, crystalline precipitates, in the shape of spheres, appear and its density is more or less a linear function of t. They are randomly distributed in the amorphous matrix. For t ? 5 to 6 hours, the number density of the spherical crystalline precipitates increases rapidly. In addition, they are no longer distributed randomly in the phase-separated amorphous matrix. Clustering is displayed. Experimental results suggest that the clustering is due to cubic crystalline precipitates that start to appear when t ≈ 5 to 6 hours.     

Effect of Heat Treatment on Microstructure and Properties of High Boron-High Speed Steel

A new type of high boron-high speed steel (HB-HSS) with different boron content was selected for oil quenching at 1050 °C, and different temperature of tempering treatment was chosen. By using optical microscopy, scanning electron microscopy, X-ray diffraction, Rockwell hardness tester, red hard treatment and wear test, the effects of heat treatment on microstructure and properties of HB-HSS were investigated. The experimental results indicate that the quenching microstructure of HB-HSS consists of α-Fe, M₂(B, C), M₇(B, C)₃ and a few of M₂₃(C, B)₆. When the tempering temperature is lower than 500 °C, the shape of carboborides will change from discontinuous sheet to continuous net, and the uniformity in microstructure is improved, and the hardness is not changed during the process. When the tempering temperature is higher than 500 °C, the continuous net of M₂(B, C) is recovered. When the tempering temperature is higher than 600 °C, the microstructure of HB-HSS get thickened because of overheating, and the hardness get significantly reduced. With the increase of tempering temperature, the weight loss of the sample is decreased, and the wear resistance of the sample is increased. When tempering temperature exceeds 500 °C, the weight loss of the sample has an obvious increase and its wear resistance decreases. The wear resistance of the sample decreases after the red-hardness treatment. The wear loss is about 8.4 mg when the boron content is 2.0% and the tempering temperature is 500 °C, which is the best of test samples.     

Process Parameters on the Crystallization and Morphology of Hydroxyapatite Powders Prepared by a Hydrolysis Method

The effects of process parameters on the crystallization and morphology of hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂, HA) powders synthesized from dicalcium phosphate dihydrate (CaHPO₄·2H₂O, DCPD) using a hydrolysis method have been investigated. X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) were used to characterize the synthesized powders. When DCPD underwent hydrolysis in 2.5 NaOH solution (Na_(aq)) at 303 K to 348 K (30 °C to 75 °C) for 1 hour, the XRD results revealed that HA was obtained for all the as-dried samples. The SEM morphology of the HA powders for DCPD hydrolysis produced at 348 K (75 °C) shows regular alignment and a short rod shape with a size of 200 nm in length and 50 nm in width. With DCPD hydrolysis in 2.5 M NaOH_(aq) holding at 348 K (75 °C) for 1 to 24 hours, XRD results demonstrated that all samples were HA and no other phases could be detected. Moreover, the XRD results also show that all the as-dried powders still maintained the HA structure when DCPD underwent hydrolysis in 0.1 to 5 M NaOH_(aq) at 348 K (75 °C) for 1 hour. Otherwise, the full transformation from HA to octa-calcium phosphate (OCP, Ca₈H₂(PO₄)₆·5H₂O) occurred when hydrolysis happened in 10 M NaOH_(aq). FT-IR spectra analysis revealed that some carbonated HA (Ca₁₀(PO₄)₆(CO₃), CHA) had formed. The SEM morphology results show that the 60 to 65 nm width of the uniformly long rods with regular alignment formed in the HA powder aggregates when DCPD underwent hydrolysis in 2.5 M NaOH_(aq) at 348 K (75 °C) for 1 hour.     

Characterisation-Assisted Reduction Roasting of BHJ,West Singhbhum,Jharkhand, India

During the mining of high-grade iron ore, considerable amount of waste is generated. This poses a serious challenge to the environment as well as humans. But, with the depletion of high-grade ores, the Banded Haematite Jasper (BHJ) ore generated as a waste has attracted attention as an alternative source of iron. The purpose for this study is to develop the energy efficient process route for harnessing the Banded Hematite Jasper. Utilisation of the ore as a source of iron will also serve the additional purpose of getting rid of a major burden on the environment. Reduction roasting is a promising route for the beneficiation of the ore for the recovery of iron values profitably. However, no studies have been reported correlating the influence of the properties of the ore on the roasting process. This is crucial for developing a viable process route for reduction roasting. Preliminary characterization study of the sample indicated the presence of prismatic and specularity hematite grains embedded in fine grained siliceous matrix and vice versa. The ore contained 43.06% Fe, 36.54% SiO₂ and 0.21% Al₂O₃. Davies Tube magnetic separator of the ore indicated the absence of highly magnetic materials in the ore. Magnetic separation of the roasted ore resulted in significant enrichment of the ore with respect to iron. The optimized parameters for reduction roasting were 13 mm particle size, 60 min roasting time and 600 °C temperature.     

Reverse Shape Memory Effect Related to α → γ Transformation in a Fe-Mn-Al-Ni Shape Memory Alloy

In this study, we investigated the shape memory behavior and phase transformations of solution-treated Fe_43.61Mn_34.74Al_13.38Ni_8.27 alloy between room temperature and 1173 K (900 °C). This alloy exhibits the reverse shape memory effect resulting from the phase transformation of α (bcc) → γ (fcc) between 673 K and 1073 K (400 °C and 800 °C) in addition to the shape memory effect resulting from the martensitic reverse transformation of γ′ (fcc) → α (bcc) below 673 K (400 °C). There is a high density of hairpin-shaped dislocations in the α phase undergoing the martensitic reverse transformation of γ′ → α. The lath γ phase, which preferentially nucleates and grows in the reversed α phase, has the same crystal orientation with the reverse-transformed γ′ martensite. However, the vermiculate γ phase, which is precipitated in the α phase between lath γ phase, has different crystal orientations. The lath γ phase is beneficial to attaining better reverse shape memory effect than the vermiculate γ phase.     

Absorption behavior of lattice oxygen in Ce_(0.8)Y_(0.2)O_(2-δ) at intermediate temperature

The absorption behavior of lattice oxygen for Ce_(0.8)Y_(0.2)O_(2-δ)(YDC) crystal was investigated. Combined with TG-DSC, XRD, Raman and XPS characterization, lattice oxygen absorption occurs at intermediate temperature(from 500 to 800 ℃),which is related to the oxygen vacancies consumption,and no phase change is observed in this process. In electric conductivity relaxation(ECR) experiment, prolonged oxygen diffusion process is observed above 600 ℃, which may be caused by oxygen absorption process. And through ECR experiments,the bulk diffusion coefficient D_(chem) and surface exchange coefficient K_(ex) for YDC dense sample are measured as 6,5×10~(-5)-2×10~(-4)cm~2/s and K_(ex)=2×10~(-4)-9×10~(-4)cm/s at intermediate temperature range.     

Bilinear Coffin–Manson Relationship in Thin Sheets of Interstitial-Free Steel

Bilinear Coffin–Manson (C-M) as well as cyclic stress–strain (CSS) relationship is observed during low-cycle fatigue study (strain amplitude ?ε _t/2 = 0.0015 to 0.004) of an interstitial-free (IF) steel sheet unlike some of the earlier reports. In this work, an attempt has been made to correlate the observed bilinearity with the evolution of dislocation substructure and the nature of cyclic strain hardening in the selected steel. To achieve this goal, some of the low-cycle fatigue (LCF) tests were interrupted after the elapse of 2, 5, 10, 20, and 50 pct of fatigue life, and the microstructures at various stages were examined using TEM. Cyclic hardening at low-strain amplitudes (?ε _t/2 ≤ 0.0020) is predominantly due to dislocation–dislocation and dislocation–precipitation interaction. On the other hand, at high-strain amplitudes (?ε _t/2 > 0.0020), subgrains start forming much earlier in fatigue life, and there is an additional contribution of subgrains toward the total hardening. The above phenomenon leads to a difference in the values of cyclic strain-hardening exponents, e.g., 0.24 at low (?ε _t/2 ≤ 0.0020) and 0.45 at high ?ε _t/2, respectively. The above difference is reflected in the bilinear C-M plot around the transition ?ε _t/2 of 0.0020 as also observed in the CSS plot.     

Reduction of Sn-Bearing Iron Concentrate with Mixed H<Subscript>2</Subscript>/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H₂/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H₂, 28.5 vol pct CO, and 66.5 vol pct CO₂ (CO/(CO + CO₂) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H₂, 50 vol pct CO (CO/(CO + CO₂) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.     

Preparation of Industrial Manganese Compound from a Low-Grade Spessartine Ore by Hydrometallurgical Process

The increasing global demands for pure manganese in steel production and manganese compound as dietary additives, fertilizer, pigment, cells and fine chemicals production cannot be over-emphasized. Thus, continuous efforts in developing low cost and eco-friendly route for purifying the manganese ore to meet some defined industrial demands become paramount. Therefore, this study focused on reductive leaching and solvent extraction techniques for the purification of a Nigerian manganese ore containing admixture of spessartine (O_96.00Mn_24.00Al_16.00Si₂₄.₀₀) and quartz (Si_3.00O_6.00). During leaching, parameters such as leachant concentration and reaction temperature on the extent of ore dissolution were examined accordingly for the establishment of extraction conditions. At optimal leaching conditions (1.5 mol/L H₂SO₄?+?0.2 g spent tea, 75 °C), 80.2% of the initial 10 g/L ore reacted within 120 min. The derived dissolution activation energy (Ea) of 35.5 kJ/mol supported the diffusion reaction mechanism. Thus, the leachate at optimal leaching was appropriately treated by alkaline precipitation and solvent extraction techniques using sodium hydroxide and (di-2-ethylhexyl) phosphoric acid (D2EHPA) respectively, to obtain pure manganese solution. The purified solution was further beneficiated to obtain manganese sulphate monohydrate (MnSO₄.H₂O, melting point?=?692.4 °C: 47-304-7403) of high industrial value. The unleached residue (~?19.8%) analyzed by XRD consisted of silicileous impurities (SiO₂) which could serve as an important by-product for some defined industries.