Ni Extraction Research Articles

HPAL of a lateritic nickel ore: An investigation on the relationship between nickel and cobalt extraction and acid consumption

Nickel and cobalt raw materials have become essential in industries like batteries such as robotics, and drones, which are considered as future technologies due to their expanding applications and diversity. Research towards the development of environmentally friendly and relatively low-cost alternative methods for extracting nickel, particularly from low-grade deposits, is becoming increasingly crucial. Laterite ores processing is plagued by high reagent consumption and scale formation. This study focused on investigating the relationship between Ni and Co extraction and acid consumption in the high-pressure acid leaching of lateritic ore, as well as the characterization of leach residue. Analysis has shown that the lateritic ore contains 1.05 % Ni, 0.05 % Co and 21.94 % Fe. In the acid leaching tests based upon a Box-Behnken Design, the initial acid concentration and leach time have a beneficial effect on the Ni extraction (70–94 %). Cobalt extractions ranged between 93 % and 96 %. To facilitate Fe dissolution and increase Ni extraction, cuprous ions were added into the leach solution. Moderate level copper addition (0.025 M) resulted in a significant improvement in Ni extraction, whereas high levels of cuprous addition (0.050 M) did not have further benefit. It has been noted that adding cuprous ions significantly reduces the amount of scale that forms in the autoclave. The lowest Ni extraction was obtained under two different test conditions that did not include copper ions. Increased acid addition was correlated with the increase in Ni leaching and decreased Fe content in residue. There will exist an optimal situation where the acid addition is enough to enhance Ni dissolution and the Eh condition, leading to minimal dissolved Fe.

Hydrometallurgical Processing of a Low-Grade Sulfide Copper–Nickel Ore Containing Pt and Pd

The goal of the present work was to study the recovery of copper, nickel, and platinum group metals (PGMs) (Pt and Pd) from low-grade copper–nickel ore containing pyrrhotite, pentlandite, and chalcopyrite by column bioleaching followed by cyanidation. The ore sample contained the following: Ni—0.74%, Cu—0.23%, Fe—14.8%, Stotal—8.1%, and Ssulfide—7.8%. The Pt and Pd contents in the ore sample were 0.2535 and 0.515 g/t, respectively. Biological leaching in columns was carried out at 25, 35, and 45 °C for 140 days. A mixed culture of acidophilic microorganisms was used as an inoculum. Cu and Ni extraction depended on temperature, and at 45 °C, copper and nickel recovery was the highest, being 2.1 and 1.8 times higher than that at 25 °C, respectively. As a result, up to 35% of nickel and up to 10% of copper were recovered by bioleaching within 140 days. Bioleaching resulted in an increase in Pt and Pd recovery by cyanidation, but the effect on Pd recovery was insignificant. Pt recovery varied in the range of 3–40% depending on process conditions; Pd recovery was 44–55%.

Sulfuric Acid Baking and Fe(III)-Cl--H2SO4 Leaching Behavior of Ni- and Cu-Containing Sulfide and Silicate Rich Suhanko Concentrate.

Ni- and Cu-rich concentrate from a new site in Suhanko, Finland, was investigated. Mineral phases identified included talc, chalcopyrite, kaolinite, and pyrrhotite with 3.2% Cu and 1.5% Ni, and the latter is associated with pyrrhotite. In addition, the concentrate contained the precious elements Pd (14.9 g/t), Ag (17.1 g/t), Pt (2.1 g/t), and Au (1.1 g/t). This concentrate was baked and leached using a Fe(III)-Cl--H2SO4 system. The results showed that the leaching efficiencies of Ni, Cu, and Si from raw concentrate were 60%, 40%, and 5%; however, those from baked concentrate were 96%, 60%, and below 0.1%, indicating that the baking process enhanced Ni and Cu extraction while simultaneously inhibiting the dissolution of Si, which was due to the baking process liberating the associated Ni and Cu by the oxidation of chalcopyrite and pyrrhotite and converting the acid-soluble silicate into an insoluble form. Sulfuric acid leaching solution with Fe(III) as oxidant and Cl- as lixiviant was shown to be effective at leaching Ni (97%), Cu (62%), and Ag (89%), while simultaneously enriching the PMs Pd, Pt, and Au in the residue.

Valorization of spent catalyst of sponge iron production industries into high-purity metallic nickel via a novel three-step method of leaching, cementation and purification

In the present study, a three-step flowsheet combining hydrometallurgical extraction, electrochemical recovery, and purification steps is developed to investigate the possibility of recovering high-purity metallic nickel powder from the spent catalyst of the sponge iron production industry. In the extraction step, the Response Surface Methodology (RSM) is used to study and optimize the effect of temperature (25–85 °C), time (30–120 min), acid concentration (1–5 M), and NaCl concentration (0–0.16 g/mL) on the Ni and Al extraction efficiency with the help of the Design-Expert software. The optimal conditions for extracting 100 % Ni with 1.25 % Al impurity are 75 °C, 190 min, 3 M H2SO4, and 0.13 g/mL NaCl. During the electrochemical recovery step, Ni+2 ions from the leached solution were cemented by Al powder to produce metallic nickel powder. The solution’s initial pH, temperature, reaction time, and Al particle size are the process restrictions leading to a decrease in the efficiency and purity of the nickel powder. At this step, more than 99 % of the nickel ions, with more than 98 % purity, were obtained as magnetic nickel powder using the optimal temperature of 80 °C, and solution initial pH of 0.2, by using Al powder with less than 65 μm in particle size. At these operating conditions, the Al consumption was 7.5 times greater than the stoichiometric value. In the final step, the Al impurity in the synthetic nickel powder was removed using 1.5 M sodium hydroxide for 60 min, and the nickel powder was purified to 99.9 %. The ICP, SEM, and EDS analyses were used to determine the quality of the nickel powder.

Disruption of a three-component solution as a novel strategy for Cu and Ni extraction from vegetable oils for their determination by GF AAS

In this work, we propose a novel approach for extracting Cu and Ni from vegetable oils (which can be expanded to other metals). The method is based on the transference of the analytes to an aqueous acid phase due to the disruption of a three-component solution. The extraction was carried out in two steps. In the first step, a three-component solution was prepared comprising the sample, 1-octanol, and HNO3 solution. Next, the homogeneous system was disrupted by adding 1.0 mL of deionized water, and two phases were formed. The aqueous extract deposited in the bottom of the flask was collected with a micropipette, and Cu and Ni were determined by graphite furnace atomic absorption spectrometry (GF AAS). The developed method presented limits of quantification (LOQ) of 0.25 and 0.17 ng g−1 for Cu and Ni, respectively, and was successfully applied in the analysis of eleven oil samples from different origins.

Liquid-solid phase separation and recycling of permalloys in liquid Mg

Liquid-solid phase separation of permalloy in liquid Mg results in selectively dissolved Ni, which provides a unique opportunity for the design of immiscible heterogeneous composite materials and the comprehensive metal recycling of permalloy scraps. A guideline of the alloy design for the liquid-solid phase separation system was proposed. The effects of immersion temperature and time on the Ni extraction were studied by an experimental method. The diffusion behavior of Ni from the permalloy to liquid Mg and the microstructure evolution in the permalloy during the liquid-solid phase separation were discussed. The results show that the Ni in the permalloy was quickly extracted into the liquid Mg and formed an Mg-Ni alloy, while the other components such as Fe, Co, and Mn were held back in the phase-separated permalloy. The phase-separated permalloy with the solidified Mg exhibits a three-dimensional (3D) Fe/Mg bicontinuous composite structure. Furthermore, simple treatments were carried out for the reaction products such as the Fe/Mg bicontinuous composite and the Mg-Ni alloy, and the recycling strategies for functionalization of these treated reaction products were provided. A 3D porous Fe-based alloy with electromagnetic interference (EMI) shielding efficiency of 52 dB can be obtained if Mg is removed from the Fe/Mg bicontinuous composite. Instead of the complete separation of pure Ni from the recycled Mg-Ni alloy by vacuum distilling, the Mg-Ni alloy can be enriched into Mg2Ni as an initial hydrogen storage material.

Transformation of the crystal structure of Ni0.5TiSe2 under in situ heating.

The crystal structure of the Ni0.5TiSe2 compound has been studied in situ in the temperature range of 25-1000 °C using synchrotron radiation X-ray diffraction. The previously known order-disorder transition in the Ni sublattice at ∼100 °C was found to be a second-order phase transition and belongs to the 3D Ising universality class. Reversible extraction of nickel selenides was observed in the temperature range of 275-975 °C. It was explained in terms of Ni extraction from Ni0.5TiSe2 due to the thermal widening of the Ni 3d/Ti 3d/Se 4p impurity band. The Ni-TiSe2 phase diagram follows the typical pattern of MxTiSe2 (M - transition metal) compounds.

Selective solvent extraction of nickel and cobalt from a Ni lateritic sulfuric solution using synergism caused by LIX860N-IC and Versatic 10

This work investigated the efficiency of the LIX860N-IC + Versatic 10 synergistic system (pH range 2–6, 40 °C) to treat an aqueous sulphate solution containing Ca, Co, Cu, Mg, Mn, Ni, and Zn, which mimics a liquor obtained by the sulfation-roasting-leaching process applied to a lateritic Brazilian Ni ore, after precipitation of Fe, Al, and Cr. Almost complete extraction of Cu was observed at pH 2 (1 stage, A/O = 1:1), while a rise in the selectivity of Ni/(Mn + Zn) and Co/(Mn + Zn) was identified at pH 2–6 and pH > 5, respectively. By varying both extractant concentrations, an organic phase containing 0.4 M LIX860N-IC + 0.4 M Versatic 10 was selected to obtain high Ni and Co extractions with low Mn and Zn extractions. At the studied pH range, antagonism occurred for Ca, Cu, and Mg extractions, while synergism was found for Ni and Zn extractions. For Co and Mn, such an effect was pH dependent: antagonism at pH 2–5 and below 4.5, respectively, otherwise synergism was identified. The stoichiometry of Co and Ni extractions with the LIX860N-IC + Versatic 10 system were obtained by data fitting supported by statistical analysis. Ni and Co were complete and selectively extracted together (>99.9 %) at pH 4.5 (2 stages, A/O = 1:1.1) with low extractions of Mn (3.3 %) and Zn (20 %), leaving Ca and Mg in the raffinate. In the sequence, while Zn was completely scrubbed off from the loaded organic using a scrub solution containing 3.5 g/L Ni and 0.2 g/L Co at pH 4.5 (1 stage, O/A ≤ 15), Mn scrubbing efficiency achieved from 85.6 % to 97.8 % at an O/A ratio ranging from 5 to 25, which can be attributed to possible Mn oxidation in the extract. Finally, Ni was completely stripped out (3 stages, A/O = 10:1), using a synthetic Ni spent electrolyte (50 g/L Ni + 1 M H2SO4), while Co stripping increased from 70 % in the first stage to 75.4 % in the second, and to only 76 % in the third stage, indicating that Co oxidation might have occurred in the loaded organic solution. The remaining Co in the extract was stripped out with 5 M HCl (2 stages, A/O = 1:1). Consequently, to avoid Mn and Co oxidations in the loaded organic solution, the solvent extraction circuit with LIX860N-IC + Versatic 10 requires an operation under an inert atmosphere.

Recovery of Nickel from Recycled NiO by Acid Leaching

The work done here deals with the extraction of Nickel from the recycled NiO material. The as such material characterized by ICP showed Nickel content of 75.14% along with other major metals such as Ca, Mg, Al, Co, and Fe. Different factors were studied affecting the efficiency of the Nickel extraction such as type of acid, organic (Citric acid) and inorganic (H2SO4), concentration of acid, temperature, stirring rate and solid liquid ratio using 2-level 1/4th factorial experimental design. The results showed that between two types of acids, Nickel leaching is higher in Inorganic acid system (H2SO4). Furthermore, for H2SO4 acid system S/L ratio is the most effective parameter for Ni extraction. Whereas acid concentration affects more for Fe/Ni selectivity. The importance of this study is in the Li-ion battery sector where Nickel is the vital element used in the cathode material synthesis.

Selective extraction of nickel and cobalt from disseminated sulfide flotation cleaner tailings using alkaline glycine-ammonia leaching solutions

Millions of tons of nickel-bearing tailings, derived from disseminated sulfide resources, has been or are being dumped as waste and the recovery of metals from these tailings is insignificant. There are no economic hydrometallurgical processes to recover valuable metals from such wastes due to their low metal recovery, their alkaline high-magnesium mineralisation, and high reagent requirement. This study presents a novel alkaline process of glycine leaching to extract nickel and cobalt from such tailings. The outcomes of the experimental tests of using an alkaline glycine-based lixiviant system to extract nickel and cobalt from a float tailing material containing 0.79 % Ni and 0.02 % Co respectively are presented in this study. A comparison between using ammonia and sodium hydroxide as pH modifiers was conducted and the leaching performance of glycine-ammonia has been found to be superior based on both metal extractions and leaching kinetics. The use of resin-in-leach (RIL) to recover Ni and Co from glycine-ammonia leaching solution enhanced Ni extraction by ∼ 10 %. Grinding of the float tailing sample to a P80 of 15 µm enhanced both Ni and Co extraction by 10–15 %. Increasing the temperature to 45 °C considerably enhanced the metal leaching at which the highest Ni and Co extractions were achieved at 88 % and 90 %, respectively. Controlling dissolved oxygen (DO) levels during the leaching significantly increased the leaching kinetics and decreased the leaching time from 48 to 24 h. QEMSCAN analysis confirmed the selectivity of the alkaline glycine-based system to leach Ni, Co and Cu over impurities such as Fe, Mn and Mg. Two conceptual block diagram flowsheets were proposed for Ni and Co extraction from the float tailings using an alkaline glycine-based leaching process, where the Ni in the original ore is mineralised in an ultramafic, highly disseminated form of pentlandite in a magnesium-rich alkaline gangue matrix.

Cobalt and nickel separation in aqueous two-phase systems with polyethylene glycol 20,000 and sodium electrolytes

The separation of Co(II) and Ni(II) in aqueous two-phase systems (ATPSs) formed by the polymer polyethylene glycol 20,000 and several sodium electrolytes, coupled with the organic extractant 1-nitroso-2-naphthol was studied. First, the liquid-liquid equilibrium experiments were carried out to describe the phase diagrams of the ATPS. Then, the metal separation efficiency was evaluated considering several factors. It was observed that pH had a great influence on the selective metal chelation. When lowering the pH to 2 and 1 in the system with sodium sulfate, it was possible to suppress the Ni extraction under 5%. These results showed that the differences in the metal chelate stabilities could displace the equilibrium reaction with Ni(II) for selective extraction. In addition, experimental results showed that the interactions between metal cations and the salt anions also determined the separation efficiency. For the system with sodium sulfate (Na2SO4), Ni(II) extraction was suppressed at pH 2, but when sodium citrate (Na3C6H5O7) was used, the suppression occurred at pH lower than 0.5, while sodium tartrate (Na2C4H4O6) and sodium hydrogen phosphate (Na2HPO4) were not suitable for selective extraction. High separation factors of 11,080, 1136, and 3300 were obtained for the aqueous systems with Na2SO4 at pH 2, and pH 1, and Na3C6H5O7 at pH 0.5, respectively. Finally, the extraction at higher metal ion concentrations was tested. When the concentration of 1N2N was 1000 mg/kg, the maximum amount of extracted Co reached about 85 mg/kg within 15 min, which corresponds to complete extraction considering a metal:1N2N ratio of 1:4.

Evaluating cationic extractant systems containing Versatic 10 on the solvent extraction of metals from an Ni lateritic sulfuric solution

The solvent extraction of Ni, Co, Cu, Ca, Mn, Mg, and Zn was evaluated in this work using Versatic 10 and its mixture with D2EHPA, Cyanex 272, Cyanex 301, LIX 84-I, and LIX 860N-IC. The aqueous phase reproduces a liquor obtained by applying a sulfation-roasting-leaching process in an Ni lateritic ore after precipitation of Fe, Al, and Cr. Tests were conducted at 40 °C, A/O ratio = 1, and [extractant] = 0.5 M. It was found that Cu, Ni, Co, Zn, and Mn can be separated from Ca and Mg by Versatic 10 at pH 6.5. Similarly, Cu, Zn, Co, and Ni can be separated from Mn, Ca, and Mg by Versatic 10 + Cyanex 301 at pH 1.5, whose antagonism on Mn extractions favors Co/Mn and Ni/Mn separation at pH 1–2. Synergism was verified on Ni extractions with Versatic 10 + LIX 84-I and Versatic 10 + LIX 860 N-IC systems. Cu, Ni, and Co are preferentially extracted over Zn, Mn, Ca, and Mg by Versatic 10 mixed with LIX 860 N-IC and LIX 84-I at pH 4 and 5, respectively. Stripping tests using Ni electrolyte solution (50 g/L Ni + 1 M H2SO4) from the loaded Versatic 10 + LIX 860 N-IC resulted in the recovery of 80% Ni, 70% Co, and 42% Cu. These four organic systems may have potential applications in direct SX operations. Conversely, Versatic 10 + D2EHPA and Versatic 10 + Cyanex 272 preferentially extract some impurities over Co and Ni. At pH 3, Zn, Ca, Cu, and Mn can be removed over Co and Ni using Versatic 10 + D2EHPA; synergism was found to Mn extractions. Versatic 10 + Cyanex 272 separated Zn, Cu, and Mn at pH 3.5 leaving Co, Ni, Ca, and Mg in the raffinate; synergism was found to Ca extractions. Targeting the extraction of impurities over Co and Ni, Versatic 10 + D2EHPA is superior to Versatic 10 + Cyanex 272, with potential application to treat liquors obtained from the dissolution of MHP.

Selective extraction of Ni and Co from a pyrrhotite-rich flotation slime using an alkaline glycine-based leach system

Ni and Co, mostly produced from sulfide resources, are critical energy metals required for the green energy transition. A significant portion of the Ni and Co in the processed ore, particularly for disseminated mafic/ultramafic ores, is not recovered due to the deportment to fine slimes which has been dumped as tailings during the flotation process. This study applied an alkaline glycine-based leaching method to selectively recover Ni and Co from a pyrrhotite-rich flotation slime and investigated the deportment of impurities. Leaching variables, including dissolved oxygen (DO) level (5–25 ppm), pH modifier (NaOH, KOH and ammonia), particle size and pre-oxidation, were investigated. The highest extractions of 86.2 % for Ni and 79.7 % for Co were achieved by leaching at glycine/(Ni + Cu) molar ratio of 4, DO of 15 ppm, pH of 10.2 (adjusted with ammonia), 10 % solids and 30 °C using a sample size at a grind size P80 of 17 µm within 72 h. Ni that is mineralised in pentlandite can be easily leached by glycine, and oxygen addition is essential for the extraction of Ni and Co when mineralised as sulfides. The study has shown a higher overall metals extraction and faster leaching kinetics, shortening the leaching from 72 to 24–48 h, when ammonia was used as a pH modifier. The alkaline glycine-based leaching achieved both higher Ni and Co extractions and higher rejections of impurities compared with conventional sulfuric acid leaching, with the concentrations of Fe being <250 ppm and Ca and Mg <15 ppm in the leachate. Residue analysis revealed a mechanism of preferable dissolution of pentlandite over pyrrhotite. The Fe and Mg deportment before and after leaching remained similar, which confirmed the high selectivity of the alkaline glycine-based leaching.

Simplified solvent extraction process for high-purity Ni/Co mixed solution for lithium–ion batteries

ABSTRACT The demands for Ni-based raw materials increase as Ni–Co–Mn ternary cathode materials become the main axis of the battery industry. Conventional hydrometallurgical process to produce raw materials from Ni ore for battery application is as follows: (i) leaching of metal ions by acid, (ii) solvent extraction process to extract target metals, and (iii) crystallization process to produce final single-metal compound as powder products. The conventional solvent extraction process is a three-circuit process comprising impurity removal, Co extraction, and Ni extraction circuits. Unlike conventional process, in this work, we suggest a simplified two-circuit process to simultaneously extract Ni and Co to produce Ni/Co mixed solution for cathode material precursor production. Accordingly, the efficiency of site utilization can be maximized by reducing the investment cost for the manufacturing process and downsizing mixer-settler facilities. Further, eco-friendly effects such as reducing the consumption of titrants and cutting down the process costs and wastewater discharge can be realized.

Green recovery of Li, Ni, and Mn from spent xLi2MnO3·(1-x)LiMO2 cathode materials: Experimental study and mechanism analysis

Recycling of spent lithium-ion batteries (LIBs) cathode materials has become a hot research area owing to limited resources, environmental problems, and strong global demand for LIBs raw materials. However, among multiple types of spent LIBs cathode materials, the recycling of spent xLi2MnO3·(1-x)LiMO2 cathode materials has not been studied and remains challenging. Herein, a green and efficient process has been developed for the simultaneous recovery of Li, Ni, and Mn from spent xLi2MnO3·(1-x)LiMO2 cathode materials by an ammonium sulfate roasting method. At optimal conditions of the roasting temperature of 450 °C, the (NH4)2SO4-to-spent xLi2MnO3·(1-x)LiMO2 mass ratio of 3:1, and the roasting time of 24 min, the spent xLi2MnO3·(1-x)LiMO2 phase was completely destroyed and converted into water-soluble metal-ammine-sulfates and metal-sulfates, resulting in that 99.41% Li, 98.67% Ni, and 98.61% Mn were rapidly extracted. Furthermore, possible conversion mechanisms and the kinetics for the roasting process were both investigated in detail, combined thermodynamics, DSC-TG, macro–micro scale analyses and DFT calculations. Finally, Mn as high-purity MnSO4 products with a purity of 99.98%, and Li and Ni as Li2SO4-NiSO4 mixture products, were efficiently recovered via (NH4)2SO3 precipitation, oxidation leaching, extraction and stripping, and evaporative crystallization. Compared with other current recovery process, this work shows better economic and environmental benefits, while maintaining the considerable Li, Ni, and Mn extraction yields, which is expected for the recycling of spent xLi2MnO3·(1-x)LiMO2 cathode materials in the future.

A sustainable route for the recovery of metals from waste printed circuit boards using methanesulfonic acid

The rapid increase in electronic waste (e-waste) generation and its unsustainable management pose a threat to the environment and human well-being. However, various valuable metals are present in e-waste, which makes it a potential secondary source to recover metals. Therefore, in the present study, efforts were made to recover valuable metals (Cu, Zn, and Ni) from waste printed circuit boards (WPCB) of computers using methanesulfonic acid (MSA). MSA is contemplated as a biodegradable green solvent and has a high solubility for various metals. The effect of various process parameters (MSA concentration, H2O2 concentration, stirring speed, liquid to solid ratio, time, and temperature) was investigated on metal extraction to optimize the process. At the optimized process conditions, 100% extraction of Cu and Zn was achieved, while Ni extraction was around 90%. The kinetic study for metal extraction was performed using a shrinking core model and findings showed that MSA-aided metal extraction is a diffusion-controlled process. Activation energies were found to be 9.35, 10.89, and 18.86 kJ/mol for Cu, Zn, and Ni extraction, respectively. Furthermore, the individual recovery of Cu and Zn was achieved using the combination of cementation and electrowinning, which resulted in 99.9% purity of Cu and Zn. The current study proposes a sustainable solution for the selective recovery of Cu and Zn from WPCB.

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.

Separation of Valuable Metals in The Recycling of Lithium Batteries via Solvent Extraction

With the development trend and technological progress of lithium batteries, the battery market is booming, which means that the consumption demand for lithium batteries has increased significantly, and, therefore, a large number of discarded lithium batteries will be generated accordingly. Solvent extraction is a promising approach because it is simple. Solvent extraction is low in time consumption and is easy to industrialize. This paper is focused on the selective recovery of cobalt (Co), nickel (Ni), and manganese (Mn) contained in leachate obtained by digesting a cathodic material from spent lithium batteries with hydrochloric acid. After leaching the cathodic material, Mn was selectively extracted from leachate by using solvent extraction with D2EHPA diluted in kerosene in an optimized condition. Afterward, Co was extracted from the Mn-depleted aqueous phase using Cyanex272 diluted in kerosene. Finally, the raffinate obtained via a stripping reaction with H2SO4 was used in the Ni extraction experiments. Cyanex272 extractant was employed to separate Ni and Li. The process can recover more than 93% of Mn, 90% of Co, and 90% of Ni. The crucial material recovered in the form of sulfuric acid solutions can be purified and returned to the manufacturer for use. This process proposes a complete recycling method by effectively recovering Mn, Co, and Ni with solvent extraction, to contribute to the supply of raw materials and to reduce tensions related to mineral resources for the production of lithium batteries.

Experimental and DFT investigations on the supramolecular mechanism of Ni(II) extraction via D2EHPA blended 1-octanol extractant: Application of vegetable oils as diluents

Experimental and DFT investigations on the supramolecular mechanism of Ni(II) extraction via D2EHPA blended 1-octanol extractant: Application of vegetable oils as diluents

Solvent extraction of nickel from iron and cobalt containing sulfate solutions

In this study, solvent extraction is applied for extracting nickel from sulfate solutions containing iron and cobalt ions. This process can also be applied for the cleaning of waste solutions and for increasing solution concentrations after the leaching of low-grade nickel ores. Di-2-Ethylhexyl phosphoric acid (D2EHPA) was used as an extractant for this purpose. Effects of pH, aqueous/organic (A/O) phase ratio, iron, and cobalt ion contents of the solution on nickel extraction efficiency were investigated. The McCabe-Thiele diagrams for extraction and stripping steps were developed to determine the number of stages required. A total of two stages were required for 96.3% of Ni extraction and a total of two stages to strip nickel with 98% efficiency.