Low-grade Laterite Research Articles

Preparation of Nickel–Iron Concentrate from Low-Grade Laterite Nickel Ore by Solid-State Metalized Reduction and Magnetic Separation

Preparation of Nickel–Iron Concentrate from Low-Grade Laterite Nickel Ore by Solid-State Metalized Reduction and Magnetic Separation

Aspects of Nickel, Cobalt and Lithium, the Three Key Elements for Li-Ion Batteries: An Overview on Resources, Demands, and Production.

With the booming of renewable clean energies towards reducing carbon emission, demands for lithium-ion batteries (LIBs) in applications to transportation vehicles and power stations are increasing exponentially. As a consequence, great pressures have been posed on the technological development and production of valuable elements key to LIBs, in addition to concerns about depletion of natural resources, environmental impacts, and management of waste batteries. In this paper, we compile recent information on lithium, nickel, and cobalt, the three most crucial elements utilized in LIBs, in terms of demands, current identified terrestrial resources, extraction technologies from primary natural resources and waste. Most nickel and cobalt are currently produced from high-grade sulfide ores via a pyrometallurgical approach. Increased demands have stimulated production of Ni and Co from low-grade laterites, which is commonly performed through the hydrometallurgical process. Most lithium exists in brines and is extracted via evaporation-precipitation in common industrial practice. It is noteworthy that at present, the pyrometallurgical process is energy-intensive and polluting in terms of gas emissions. Hydrometallurgical processes utilize large amounts of alkaline or acidic media in combination with reducing agents, generating hazardous waste streams. Traditional evaporation-precipitation consumes time, water, and land. Extraction of these elements from deep seas and recycling from waste are emerging as technologies. Advanced energy-saving and environmentally friendly processes are under extensive research and development and are crucial in the process of renewable clean energy implementation.

Sustainable Utilization of Fe(Ⅲ) Isolated from Laterite Hydrochloric Acid Lixivium via Ultrasonic-Assisted Precipitation to Synthesize LiFePO4/C for Batteries.

Ultrasonic-assisted precipitation was employed to sustainably isolate Fe in the hydrochloric acid lixivium of low-grade laterite for the synthesis of battery-grade iron phosphate. The recovery efficiency of Ni and Co exceeded 99%, while the removal efficiency of the Fe impurity reached a maximum of 95%. Precipitation parameters for the selective isolation of Fe (MgO precipitant, pH 1, 70-80 °C) were optimized and used in ultrasonic precipitation experiments. The use of ultrasonic waves in the precipitation process enhanced micromixing by reducing the size of primary grains and mitigating particle agglomeration, thereby significantly improving the purity of the isolated compound and providing high-quality iron phosphate (FePO4·2H2O). The LiFePO4/C composite prepared from as-precipitated FePO4 exhibited excellent electrochemical performance, with a discharge capacity of 149.7 mAh/g at 0.1 C and 136.3 mAh/g at 0.5 C after 100 cycles, retaining almost 100% cycling efficiency. This novel and facile method for iron removal from laterite acid lixivium not only efficiently removes excess iron impurities leached due to the poor selectivity of hydrochloric acid, but also enables the high-value utilization of these iron impurities. It enhances economic benefits while simultaneously alleviating environmental pressure.

High-Grade Ferronickel Concentrates Prepared from Laterite Nickel Ore by a Carbothermal Reduction and Magnetic Separation Method.

Nickel is widely used in industrial processes and plays a crucial role in many applications. However, most of the nickel resource mainly exists as nickel oxide in laterite nickel ore with complex composition, resulting in difficulty in upgrading the nickel content using physical separation methods. In this study, high-grade ferronickel concentrates were obtained through a carbothermal reduction and magnetic separation using laterite nickel ore and anthracite as raw materials. The effects of different types of additives (CaF2, Na2SO4, and H3BO3), carbon ratio (the molar ratio of oxygen atoms in the laterite nickel ore to carbon atoms in anthracite), and grinding time on the recoveries and grades of ferronickel concentrates were experimentally investigated, along with the microstructure and chemical composition of the products. CaF2 was proved to be the primary active additive in the aggregation and growth of the ferronickel particles and the improvement of the grade of the product. Under the optimal conditions of CaF2 addition of 9.85 wt%, carbon ratio of 1.4, and grinding time of 240 s, high-grade magnetically separable ferronickel concentrate with nickel grade 8.93 wt% and iron grade 63.96 wt% was successfully prepared. This work presents a practical method for the highly efficient recovery and utilization of iron and nickel from low-grade laterite nickel ore, contributing to the development of strategies for the sustainable extraction and utilization of nickel resources.

Nickel recovery from low-grade laterites: study of thermal pre-treatments to improve the efficiency of the hydrometallurgical process

Nickel recovery from low-grade laterites: study of thermal pre-treatments to improve the efficiency of the hydrometallurgical process

Effect of pretreatments to improve nickel leaching from laterites in carboxylic media: Mechanism and kinetic model

In recent years and with the rapid development of electric vehicles and batteries, the demand for nickel as an important material in clean energy technologies has increased. Extensive research efforts have been devoted to develop a clean alternative technology capable of obtaining this metal from low-grade laterite. This study investigated the laterite leaching using sodium citrate as an alternative reagent to conventional inorganic acids; the effect of pyro- and hydrometallurgical pretreatments on ore morphology and structure was evaluated. The results showed that although citrate tends to be selective for nickel, its dissolution is associated to the iron. The decreasing core model (SCM) was used to determine the best fit for the experimental data. Using the Arrhenius expression, the apparent activation energy for the nickel and iron solutions was estimated, verifying a chemical reaction control in the process.

Surfactant-enhanced extraction of valuable metals from limonitic laterite: Porous kinetics and mechanism analysis

The efficient extraction of valuable metals from low-grade mineral resources is an important initiative to implement the concept of carbon neutrality and achieve energy conservation and emission reduction. Atmospheric leaching of laterite ores is widely noted for its low cost. However, low extraction and difficulties in slurry filtration have severely restricted its development. Inspired by our previous studies on the porous kinetics, two options for improving the nitric acid atmospheric leaching (NAAL) of limonitic laterite are proposed. 84.85 % of Ni extraction is achieved under the optimal process conditions (Temperature: 98 °C, Time: 3.5 h, Liquid/Solid: 4.7 mL/g, and the initial nitric acid concentration: 487 g/L). After enhanced treatment, the Ni extraction is increased by 3.16 % (bleed air), 4.55 % (SDS: sodium dodecyl sulphate), and 5.67 % (DTAB: dodecyl trimethyl ammonium bromide), respectively. In addition, DTAB not only promotes the leaching of laterite ores but also improves the filtration performance of the slurry. The filtration rate was more than three times higher than in the absence of DTAB. The presence of silicic acid is responsible for the difficult filtration of the slurry and the low extraction of valuable metals. Analysis of the intensification mechanism shows that the bleed air treatment mainly eliminates the obstruction of leaching by air in the pores, thus increasing the effective reaction area. The reinforcing effect of surfactants is mainly due to the improvement of diffusion efficiency, the reduction of adsorption, and the increase in permeability. This paper provided a feasible option for the enhanced leaching of limonitic laterite, and the reinforcement mechanism was explained clearly. It not only responds to the call for energy conservation and emission reduction by achieving efficient extraction of valuable metals from low grade laterite resources, but also avoids the treatment of laterite ores by means of high temperature and pressure.

Phase transformation in the metallic reduction process of low-grade laterite nickel ores for ferronickel alloy production

The utilization of low-grade laterite ores has become necessary due to the intensive mining of high-grade nickel sulphide ores for a long time. In this study, metallic reduction roasting followed by magnetic separation to produce ferronickel alloy and abandon gangue minerals provides an effectively treatment for laterite ores. The experimental results indicate that ferronickel alloy containing more than 7.5% Ni with its recovery of 95% and more than 70% Fe with its recovery of 90% was produced successfully from the low-grade laterite ore. In the metallic reduction roasting process, the thermodynamic analysis displayed that the higher temperature promotes the conversion percentage of the oxidic nickel and iron to metallic nickel and iron. The ferronickel particle morphology with a liquid-solid growth and aggregation mechanism in the reduced laterite ore were investigated by SEM/EDS. XRD analysis revealed that the nickel laterite ore was transformed from hortonolite (MgOx · FeO2-x · SiO2) to forsterite (MgOx · CaOy · SiO2) during the metallic reduction process.

Insight into the high-efficiency separation of Si element from low-grade laterite nickel ore and the preparation of Li2FeSiO4/C cathode materials for lithium-ion batteries

In the traditional laterite nickel ore treatment process, the recovery focus is mainly on the metal elements, such as Ni, Cr, Mg, Fe, etc. However, the extremely rich Si is usually discharged in the form of waste residue, which makes it far from being fully utilized. In this paper, the alkaline hydrothermal/water leaching method of sodium hydroxide and laterite nickel ore was used to effectively recover silicon. Alkali/ore ratio of 1.2:1, hydrothermal temperature of 250 °C and holding time of 2 h are the optimum process conditions, and the leaching rate of Si can reach more than 98.8% at this condition. In addition, the conversion process of silica-containing sediment was studied, obtaining high purity SiO2. Then, the Li2FeSiO4/C cathode material for Li-ion batteries was successfully prepared by two-stage calcination process using prepared SiO2 as silicon source. The initial discharge capacity of Li2FeSiO4/C can reach 148.5 mAh·g−1 at 0.1 C. Moreover, the discharge specific capacity of Li2FeSiO4/C electrode remained above 125 mAh·g−1 after 200 cycles at 1 C. This whole process doesn’t use any reducing agent and features short process, easy to operate,economic and reasonable, which is conducive to the efficient recovery and reuse of Si element in laterite nickel ore, providing an important way and method for the development of products with high added value and high-tech content of laterite nickel ore resources.

Extraction of Ferronickel Concentrate by Reduction Roasting-Magnetic Separation from Low Grade Laterite Nickel Ore under the Action of Compound Additives

Extraction of Ferronickel Concentrate by Reduction Roasting-Magnetic Separation from Low Grade Laterite Nickel Ore under the Action of Compound Additives

Kinetics Study of Leaching Ore Nickel Laterite Using Hydrochloric Acid in Atmosphere Pressure

Leaching of nickel laterite ore at atmospheric pressure is a leaching method that can be operated at >100⁰C temperatures in an atmospheric pressure, which is applicable to a low-grade laterite ore. This research aimed to study the effect of temperature, acid concentration, and leaching time on nickel extraction percentage and the leaching kinetics. Hydrochloric acid (HCl) was used as a leaching agent and several variables were applied, i.e., temperature (80⁰C, 90⁰C, 100⁰C), HCL concentration (5 M, 6 M, 7 M), and leaching duration (120 minutes, 150 minutes, 180 minutes) to investigate their effect on nickel extraction percentage. In addition, the kinetics of the leaching process was studied using a Shrinking Core Model. The results showed that the percentage of nickel extraction increased with increasing temperature, HCl concentration, and leaching time. The lowest percentage of nickel extraction of 51.29% was obtained when 80⁰C, five molar HCl, and 120 minutes leaching duration were applied. In contrast, The highest percentage of nickel extraction of 97.22% was obtained at 100⁰C, seven molar HCl, and 180 minutes of leaching time. The kinetics study results show that diffusion through the unreacted solid product layer controls the nickel leaching rate.

Petroleum coke as reductant in co-reduction of low-grade laterite ore and red mud to prepare ferronickel: Reductant and reduction effects

Petroleum coke as reductant in co-reduction of low-grade laterite ore and red mud to prepare ferronickel: Reductant and reduction effects

Migration and Aggregation Behavior of Nickel and Iron in Low Grade Laterite Ore with New Additives

This study focused on the preparation of high-grade ferronickel concentrate, the behavior of efficient migration and the polymerization of ferronickel particles during reduction roasting, by adding calcium fluoride and a ferronickel concentrate to low-grade laterite ore from Yunnan. The effects of temperature, holding time, reductant content, ferronickel concentrate content and magnetic field intensity on the preparation of the ferronickel concentrate were studied and the optimum conditions were determined as follows: 30% ferronickel concentrate (metal Ni-4.68%, metal Fe-45.0%), 8% coal, 7% calcium fluoride, reduction temperature of 1250 °C, reduction time of 60 min and the intensity of magnetic separation is 150 mT. The proportion of nickel and iron in ferronickel concentrate was 88.7% (metal Ni-8.62%, metal Fe-80.1%), and the recovery efficiency of nickel and iron are 98.8% and 82.4%, respectively. X-ray diffraction and scanning electron microscopy indicated that ferronickel-concentrate, as an activating agent, improved the aggregation effect of ferronickel particles. The efficient migration and polymerization of ferronickel particles in the ore significantly increased the size of the ferronickel particles with additives, therefore a high-grade ferronickel concentrate was prepared, and the reduction and recovery efficiency of laterite nickel ore was improved.

Relationship between process mineralogical characterization and beneficiability of low-grade laterite nickel ore

Relationship between process mineralogical characterization and beneficiability of low-grade laterite nickel ore

Selective Recovery of Iron by Solvent Extraction from Ni-Laterite Leach Solutions, as Precursor for the Synthesis of High Added-Value Nanomaterials

Iron is the major impurity in the pregnant leaching solutions (PLS) derived from heap and atmospheric acid leaching of low-grade laterite ores. The PLS can be considered as a secondary resource for the synthesis of high added-value iron nanomaterials, provided that the iron is selectively separated from the polymetallic PLS solution. In this study, the feasibility of selective iron separation was investigated by applying a solvent extraction technique based on the use of Di-2-ethylhexyl phosphoric acid (D2EHPA) and Tri-butyl phosphate (TBP) extractants. The effect of several parameters such as initial pH and PLS composition was studied to identify the conditions allowing the maximum possible separation of iron with the minimum co-extraction of other valuable metals. It was found that the best separation of Fe could be obtained when the initial pH of the aqueous phase was regulated close to 1.4. The recovery of iron from the loaded organic phase was studied using sulfuric acid as stripping reagent and elemental iron as solid reducing agent. It was found that 90% of Fe(III) could be stripped out by applying the metallic iron (galvanic) stripping.

Ekstraksi limonit dengan metode dua tahap reduksi selektif dan magnetic separation dengan variasi waktu tahan dan suhu rendah

The use of limonite and saprolite nickel ore with low Ni content as raw material for the manufacture of FeNi metal with a content of> 5% Ni has not been widely used. This is because to process limonite and saprolite ore into high levels of FeNi concentrate, it requires greater energy. The purpose of this study was to see the beneficiation process of low grade laterite nickel ore (limonite type, with 1-2% Ni content) at low temperature and holding time with graphite reducing agents and adding additives to iron nickel concentrate and nickel iron concentrates with nickel content above 5%. The method used in this research is to provide services with temperature variations of 250°C, 300°C, and 350°C with a holding time of 60 minutes and 90 minutes in the heat process stage 1 and continued in the heat process stage 2, namely at a temperature of 1150°C with a holding time of 60 minutes. The concentrates and tailings resulted from magnetic separation were then subjected to XRF testing and optical microscopy. With the erasing process and the holding time, the nickel content was quite high, namely 5-6%. With this, it can be neglected that the beneficiation process with this method is very effective and optimal. The levels of Fe in the concentrate obtained from several tests have increased and decreased with the addition of temperature and holding time.

Study of Nickel Leaching Using Sulfuric Acid and Phosphoric Acid on The Selectivity Nickel Ore

Study of nickel leaching using sulfuric acid and phosphoric acid on the selectivity of low-grade laterite nickel ore under atmospheric conditions has been successfully carried out. In this study, the laterite nickel leaching process was carried out by varying the solution concentration and operating time. The concentrations of sulfuric acid and phosphoric acid solutions were varied at 5 M and 6 M concentrations, while the operating time was varied at 4 hours and 6 hours. For other operating conditions, it is kept constant with an operating temperature of 90 ℃, pulp density 15% w / v, particle size ≤ 200 mesh. After that, the analysis stage was carried out using an atomic absorption spectroscopy (AAS) tool to determine the nickel content in the sample. The results showed that the highest nickel recovery was obtained at the concentration of 5 M sulfuric acid solution of 2.60% and 5 M phosphoric acid of 2.59% with the optimum operating time at 4 hours of operating time.

Recovery of nickel and iron from low–grade laterite ore and red mud using co–reduction roasting: Industrial-scale test

Recovery of nickel and iron from low–grade laterite ore and red mud using co–reduction roasting: Industrial-scale test

Leaching of limonitic nickel from Sorowako with sulfuric acid at atmospheric pressure

Indonesia has the largest nickel laterite reserves in the world that it plays an important role in fulfilling the demand for stainless steel, nickel-based alloys, and the issue of using electric cars in the future. Currently, low-grade nickel laterite ore has not been maximally processed into value-added products domestically. The extraction process that is widely applied in the industry for low-grade laterite nickel ore through the hydrometallurgical route, which is the leaching method at atmospheric pressure in a sulphuric acid solution. The characterization of nickel ore from Sorowako has been studied that included water content analysis, sieve analysis, XRF analysis, XRD analysis, and leaching in sulphuric acid solution with agitation method at various leaching times. The results showed that the nickel ore sample from Sorowako had a water content of 5.51% with a dominant size fraction of -4 +14 mesh. XRD and XRF analysis results have shown that the chemical compositions of laterite nickel from Sorowako were Limonitic type of goethite (FeOOH) and quartz (SiO2) with the content of Ni, Co, Mg, and Fe of 1.5%, 0.02%, 0.05%, and 23.82%, respectively. The highest percentages of nickel and iron extract that were obtained at the 12 hour leaching time were 90.01% and 97.11%, respectively.

Analysis the Effect of Charcoal Mass Variation to Ni Content, Sinter Strength and Yield on Sintering Process of Limonitic Laterite Nickel Ore

The depletion of sulfide nickel ore and the growing of stainless steel demand each year cause the use of low-grade laterite nickel ore continues to increase. Due to very low nickel content, there is no optimal process to extract them. One of the alternative processes being developed now is the sintering-blast furnace process which produces Nickel Pig Iron (NPI). This research was conducted by sintering limonitic laterite nickel ore using charcoal as fuel and limestone as a flux. This research aims to analyze the effect of charcoal mass variation on Ni content, sinter strength, and the yield on the sintering process of limonitic laterite nickel ore. Charcoal and limestone demand calculated using energy balance and mass balance, then varied charcoal mass to feed material. Feed materials are fed in the furnace, heated at a temperature of 1200oC with 4 hours holding time. Next, the sinter yield was calculated. EDX, XRD, and Drop tests were also performed to determine Ni content, sinter compounds, and strength. The highest Ni content was 3.66% which was obtained by adding 9.9 kg charcoal. The highest sinter strength and yield also obtained by adding 9.9 kg charcoal (72.30% and 86.44%, respectively). Mayor phases which formed on sinter with 9.9 kg charcoal addition is nickel-iron oxide.