Battery Powder Research Articles

Application of the Shrinking-Core Models for Determination of Dissolution Kinetics of Mn and Zn from Spent Zinc–Carbon Battery Powder in Organic Acid Solution

Abstract In this study, dissolution kinetics of manganese and zinc from spent zinc–carbon batteries in acetic acid solution was investigated. To determine the kinetics of dissolution of manganese and zinc, shrinking core model was applied to dissolution recoveries obtained at different temperatures. As a result of kinetic studies, it was determined that manganese and zinc were dissolved in acetic acid solution by diffusion from product layer and then activation energies (Ea) were calculated.

Scalable Dry Processing of Binder-Free Lithium-Ion Battery Electrodes Enabled by Holey Graphene

To address the multitude of issues that accompany wet electrode fabrication techniques, composite lithium-ion battery (LIB) electrodes composed of solely active components (active battery material and conductive additive) are fabricated using a scalable and eco-friendly dry processing method known as dry pressing. To accomplish this, a nanoporous carbon allotrope (i.e., holey graphene or hG) acts as the compressible and conductive matrix to accommodate incompressible cathode and anode battery powders. The inherent nanoporosity facilitates the escape of trapped gases upon compression, enabling the successful formation of binderless and solventless composite electrodes independent of selected active battery powder, fabrication pressure, or pressing time. Dry pressed LIB electrodes fabricated with different processing parameters (e.g., hydraulic pressure, pressing time) are evaluated structurally and electrochemically using a model cathode material (lithium iron phosphate, LFP) in order to demonstrate the po...

A Kinetic Model for Dissolution of Zinc Oxide Powder Obtained from Waste Alkaline Batteries in Sodium Hydroxide Solutions

The determination of individual dissolution behaviors of zinc and manganese in waste alkaline battery powders is an important subject from the points of the leaching yield, design of leaching reactor, and separation and recovery steps of hydrometallurgical process. In the current study, we investigated the dissolution kinetics of zinc oxide powder. Zinc oxide was obtained from waste alkaline batteries, and sodium hydroxide solutions were used as solvent. In the experiments, the effects of solution concentration, reaction temperature, stirring speed, solid-to-liquid ratio, and particle size on the dissolution of zinc oxide were investigated. It was demonstrated that the dissolution increased with the increasing concentration, reaction temperature, and stirring speed, and with the decreasing solid-to-liquid ratio and particle size. In consequence of the kinetic analysis performed, it was found that the dissolution kinetics of zinc powder obeyed the Avrami model. Activation energy for the process was determined to be 19.42 kJ/mol. Zinc ions in the resulting solution after dissolution process was recovered in the form of hydroxy-carbonate product by precipitation method. Zinc oxide was produced by isothermal decomposition of hydroxy-carbonate product.

Vacuum drying kinetics and energy consumption analysis of LiFePO4 battery powder

As a cathode material of Li-ion battery, the lithium-ion ferrous phosphate (LiFePO4 or LFP) is widely used in the automobile industry. The drying process of LFP material influences the battery performance directly. In the paper, the vacuum drying experiment of LFP material was performed with different drying conditions. The moisture ratio and the drying rate curves were also drawn and analyzed. Eight empirical models were applied to fit the experiment data and Modified Page model was selected to analyze the drying kinetics. Meanwhile, the relative effective diffusion coefficient and the activation energy were further calculated on the basis of the Fick's equation and Arrhenius equation. The energy consumption was also discussed at the end of paper. This research can give a reference to the large scale drying of LFP powder, so that the required amount of product can be achieved in a reasonable time and minimal energy cost.

Use of adapted metal tolerant Aspergillus niger to enhance bioleaching efficiency of valuable metals from spent lithium-ion mobile phone batteries

Abstract Spent lithium-ion batteries have caused global concern owing to their rich resource metal content and high potential for polluting the environment. In the present study, a green, efficient, and simple process was developed to recycle and detoxify Li, Mn, Cu, Al, Co, and Ni from spent lithium-ion mobile phone batteries using adapted Aspergillus niger. The adaptation of Aspergillus niger to heavy metals improved the production of organic acids and the leaching efficiency of metals compared to unadapted fungi. Moreover, it decreased the time required to enter the logarithmic phase and increased the speed of acid production. In the presence of spent lithium-ion battery powder, gluconic acid was the main lixiviant produced by the adapted fungi. At a pulp density of 1% (w/v), the adapted Aspergillus niger leached 100% Li, 94% Cu, 72% Mn, 62% Al, 45% Ni, and 38% Co. The results of SEM, FTIR, XRD, EDX, and mapping analyses of the original spent battery powder and bioleached residue confirmed the effectiveness of fungal metabolites to leach the metals of spent lithium-ion mobile phone batteries.

Cyclic Voltammetry, Impedance and Thermal Properties of CoFe2O4 Obtained from Waste Li-Ion Batteries

In the present study, CoFe2O4 nanocrystals were synthesized from waste lithium ion battery powder using citric acid as eco- friendly material by hydrothermal method. The prepared materials were characterized by X-ray powder diffraction (XRD) to study particle size and crystallinity, the morphology of the nano composite are analysed by using Scanning Electron Microscopy (SEM), functional group were observed using Fourier Transform Infrared Spectrometer (FTIR). The thermal properties of CoFe2O4 nanocrystals were analysed using Thermo Gravimetric Analysis (TGA), Differential Scanning Calometry (DSC) and Differential Thermal Analysis. The synthesized nano particle was studied for the electrochemical studies such as Cyclic Voltammetry (CV), electrochemical impedance spectra, capacitance and electron transfer resistance

Recovery of Lithium, Nickel, and Cobalt from Spent Lithium-Ion Battery Powders by Selective Ammonia Leaching and an Adsorption Separation System

A novel hydrometallurgical route was developed to recover valuable metals from spent lithium-ion battery (LIB) powders. An ammonia media was utilized to selectively leach lithium, nickel, and cobalt from the pretreated spent LIB powders. Subsequently, an adsorption method was adopted to effectively separate lithium from Co2+–Ni2+–Li+–NH4+-containing leaching solutions using manganese type lithium ion-sieves as adsorbents. The results showed that the direct recovery efficiencies of lithium, nickel, and cobalt from the spent LIB powders reached 76.19%, 96.23%, and 94.57%, respectively. Also, ammonia could be closed-loop recycled, while Li2CO3, NiSO4, and CoSO4 could be obtained as products. This study provides a new pathway for recycling utilization of spent LIB powders.

Preparation of rGO/G/PANI ternary nanocomposites as high performance electrode materials for supercapacitors with spent battery powder as raw material

To improve the electrochemical energy storage performance of the graphite nanoparticles/polyaniline (G/PANI) nanocomposites prepared via chemical oxidative polymerization of aniline with the MnO2 in the spent battery powder (SBP) as oxidant, graphene oxide (GO) nanosheets were added as 2D conductive support with different feeding ratios. The electrochemical properties of the resultant ternary GO/G/PANI nanocomposites were compared with their reduction products, the reduced graphene oxide/graphite nanoparticles/polyaniline (rGO/G/PANI) nanocomposites. The results showed that the reduction of the GO/G/PANI nanocomposites with hydrazine hydrate was favorable to the capacitive property, and the rGO/G/PANI-3 nanocomposite exhibited the highest specific capacitance of 421F/g, with capacitance retention of 106.6% after 1000cycles.

Planar Mesoporous Silicon Flakes with Microns Thicknesses As an Anode Material for Li-Ion Batteries: Fabrication, Characterization and Electrochemical Tests

Conventional Li-ion batteries based on a graphite anode with any of Li-Co-(Mn, etc)-oxides cathodes and liquid electrolytes have small specific capacities due to low theoretical capacity of carbon that is of app. 372mAhs/g. Recent research revealed many new perspective materials for using instead of a carbon anode [1] and silicon is one of the best with a theoretical capacity of nearly 4200mAhs/g [2]. This emerging material has been extensively studied in a number of its structural forms, beginning from a simple planar Si wafer to more sophisticated nano-structures embedded into a Si support (wafer) or even as free standing nano-powders of different shapes and geometry, for review see [3]. In this work we studied nano-structured silicon material in form of planar mesoporous flakes with microns thicknesses in an attempt to adjust such Si powder for using it as an anode in Li-ion battery. We report here a fabrication process based on electrochemical etching of Si-wafer in a special regime that allowed not only a formation of meso pores in bulk Si but also a separation of nanostructured material into planar flakes with microns thicknesses and a collection of a final Si powder. We performed an additional coverage of an obtained material with carbon to improve electrical conductivity of the powder. Then we widely characterized both nanostructured materials to know its surface chemical compositions, internal surface areas, pore size distributions and how the performed carbon coating influenced on them. Finally, we prepared anode masses with more then 85% of silicon using standard battery powder technology with conventional binder, solvent and addition of carbon powder. A battery with Li metal as contra electrode was assembled and electrochemical tests fulfilled. Used materials, chemicals and methods: To obtain the nanostructured Si-powder the p+ doped Si wafer of 0.01-0.02 Ohm cm resistivity, 1500 microns thickness and 4cm diameter was used. The electrochemical cell provided the 12.5cm2 area for etching. 100ml of the 1:2 HF (45% conc.):EtOH electrolyte was employed to perform the anodic treatment of a wafer up to 300mkm in-depth in total. The electrochemical regime consisted in application of two anodic steps of different intensity (J1=50mA/cm2; J2=100mA/cm2) and duration (t1=600s; t2=10s) followed by a 20s time interval with zero current for relaxation of a system. This regime was subsequently applied in several cycles (up to 10) without opening the cell and an average depth in a cycle reached app.20mkm. Detailed description of similar regimes is reported elsewhere [4]. After performing all the programmed cycles, the last intensive current (more than 150mA/cm2) was applied for 20s to cut off the obtained mesoporous Si layers (future flakes) from the Si wafer. At this moment all the material was packed together that permitted its exhaustive washing with water and ethanol. Initial crashing of the layers into flakes was done in the laboratory ultrasound bath and the powder was collected into ethanol suspension. After evaporation of solvent at 50oC and additional milling of flakes in the Agatha mortar the dry material was obtained. The carbon coverage was effectuated in the 1:1 acetylene + argon atmosphere at a total gas flow of 0.5L/min and temperature of 850oC during 15 minutes, as described in [5]. Both covered and pristine mesoporous silicon materials were used for preparation of the anodes for battery tests. The weight ratio 85:7:8 between the meso-porous silicon powder, the 15% PVdF binder dissolved in NMP and the C black powder was used for preparation of the anodic masses. The electrochemical examination of the silicon electrodes was performed in double-electrode coin cells CR2032 by using a CT-3008W-5V10 mA battery testing system (Neware). Lithium metal served as the counter electrode. The electrolyte consisted of 1M LiPF6 in a solution mixture of EC/PC/DEC/EMC/PA (ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl-methyl carbonate, propyl acetate) (TC-E810 Tinci).

A Hydrometallurgical Approach to Recover Zinc and Manganese from Spent Zn-C Batteries

This study addresses the recovery of recovery of zinc (Zn) and manganese (Mn) from spent dry cell (Zn-C battery) batteries using a hydrometallurgical approach. Every year, a significant number of Zn-C dry cell batteries are consumed and disposed worldwide. Zn-C dry cell batteries constitute more than 60% of Zn and Mn together. Higher amount of Zn and Mn present in Zn-C dry cells shows an industrial interest in recycling and recovering Zn and Mn. In this study the recovery of Zn and Mn from spent dry cells was investigated through an energy efficient hydrometallurgical route. Zn-C batteries were manually dismantled to collect the battery paste. Neutral leaching was carried out to remove potassium and non-metal contents. The battery powder was leached in sulfuric acid medium with glucose as reducing agent. The experiments were conducted according to ‘24 full factorial design’. The purpose of the design was to identify the most effective and optimum condition for Zn and Mn recovery from spent Zn-C batteries. Using the optimum operating condition, up to 86.54 % of Mn and 82.19% of Zn were recovered from the original battery powder.

Study of the factors influencing the metals solubilisation from a mixture of waste batteries by response surface methodology

ABSTRACTThis paper presents an innovative process for the recovery of valuable metals from a mixture of spent batteries. Different types of batteries, including alkaline, zinc-carbon (Zn-C), nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH), lithium ion (Li-ion) and lithium metallic (Li-M) batteries, were mixed according to the proportion of the Canadian sales of batteries. A Box-Behnken design was applied to find the optimum leaching conditions allowing a maximum of valuable metal removals from a mixture of spent batteries in the presence of an inorganic acid and a reducing agent. The results highlighted the positive effect of sodium metabisulfite on the performance of metals removal, especially for Mn. The solid/liquid ratio and the concentration of H2SO4 were the main factors affecting the leaching behavior of valuable metals (Zn, Mn, Cd, Ni) present in spent batteries. Finally, the optimum leaching conditions were found as follows: one leaching step, solid/liquid ratio = 10.9%, [H2SO4] = 1.34 M, sodium metabisulfite (Na2S2O5) = 0.45 g/g of battery powder and retention time = 45 min. Under such conditions, the removal yields achieved were 94% for Mn, 81% for Cd, 99% for Zn, 96% for Co and 68% for Ni.

Recovery of Cobalt and Lithium from Spent Lithium Ion Batteries

In this research a combination of mechanical separation, reductive leaching and chemical precipitation are used to regain Li as Li2CO3 and Co as Co(OH)2 from waste lithium ion batteries. First batteries are dismantled and different component are separated. Anode and cathode foils are grinded and sieved to extract Al and Cu from spent battery powder. The separation efficiency for copper and aluminum are 97.68% and 84.41% respectively. The separated powder is leached with sulfuric acid and hydrogen peroxide solution to dissolve cobalt and lithium. The effects of sulfuric acid concentration, time, temperature, concentration of hydrogen peroxide and S/L on the leaching efficiency for cobalt and lithium are studied. Design of experiments by Taguchi method is used to determine experiments conditions, analysis the results, and identify the optimum leaching conditions. The optimum leaching conditions are 1.5 M acid concentration, 60 minute, 60 °C, 15% H2O2, and 40 g/l solid to liquid ratio. Leaching efficiencies of 94.07% Co and 98.15% Li are achieved with these optimum conditions. Leaching solution of the optimum experiment is used to recover cobalt as cobalt hydroxide and lithium as lithium carbonate by chemical precipitation. An equivalent volume of 4M NaOH is used to precipitate cobalt as cobalt hydroxide. After 1 hour 99.98%, Co is precipitated and collected by filtration and dried. After collection of the Co(OH)2 product, the remaining solution is treated with equivalent volume of "saturated solution" of Na2CO3 at 100 °C to recover lithium as Li2CO3. After 1 hour, 80 – 85 % Li is precipitated, filtrated and dried. Precipitation products are investigated with XRD, which confirmed that cobalt hydroxide and lithium carbonate are recovered from leaching solution.

Recovery Zinc and Manganese from Spent Battery Powder by Hydrometallurgical Route

Abstract Spent Zn–MnO2 battery electrode powder, containing 30.1% of Mn and 25.6% Zn was was treated via reductive leaching by H2SO4 and selective precipitation by NaOH at pH 13 for Mn(OH)2 and then pH 10 for Zn(OH)2, and the hydroxides converted respectively to MnO2 and ZnO by calcination. The effects of H2SO4 concentration, leaching time, solid-liquid ratio, reaction temperature were investigated. H2SO4 can totally dissolve Zn, but leaching rate of manganese is only 60% because of the existence of Mn (IV). Ascorbic, citric and oxalic acids were tested as the reducing agent, and ascorbic acid performs the better efficiency. The optimal reductive leaching condition were determined as 0.5 mol/L of H2SO4, 20 ml/g, 25°C, ascorbic acid dosage 10g/L for 2hours. Yielding up to 98% leaching efficiency of the two metals. The recovery rates are about 91% for Zn and 94% for Mn with high purity.

Recovery of Zn (II), Mn (II), Cd (II) and Ni (II) from the unsorted spent batteries using solvent extraction, electrodeposition and precipitation methods

This investigation presents the development of a waste batteries recycling technology, that could lead to the minimization of waste discharged and contamination problems and to the depletion of natural resources. This study mainly focused on the recovery of metals from a pregnant leach solution (PLS) obtained from a sulphuric leaching process applied to unsorted spent batteries. The PLS mainly contains Zn, Mn, Cd, Ni and Co. Cyanex 272 (di-2,4,4-trimethylpentyl phosphinic acid) was used to selectively recover Zn from the mixed solution. The Zn-Cyanex 272 was stripped and electrodeposited in metallic form and approximately 134 kg of Zn were recovered. Cd and Mn were co-extracted in the organic solvent D2EHPA (2-ethylhexylphosphonic acid) from the Zn-depleted solution and they were stripped using H2SO4. Consequently, Cd was selectively electrodeposited from a sulphate-stripped solution where the amount of Cd recovered was equal to 21.6 kg Cd per ton of waste battery powder. Residual Mn was recovered in the carbonate form by the addition of Na2CO3 (238 kg of Mn t−1 of waste battery powder). In the following step, Cyanex 272 was used to remove Co and other impurities from the Zn-Cd-Mn depleted solution, while Ni was not extracted. Finally, Ni was precipitated from the pure NiSO4 solution with Na2CO3 and 23.8 kg of Ni were recovered per ton of waste battery powder. The costs of the process develop to recover metals (including only chemical costs and energy consumption) are estimated at $814 t−1 of battery powder, while the metal revenues obtained are estimated at $2132 t−1 of battery powder. The chemical cost/metal revenue ratio is lower than 50%, which indicates that the process is feasible.

Preparation of polypyrrole nanocomposites for supercapacitor using spent battery powder as raw materials

A strategy has been developed to prepare conductive polymer-based nanocomposites as the electrode materials for supercapacitor with spent battery powder (SBP) as raw materials. Thus the waste resources from power could be sustainably recycled for new energy storage devices. The SBP containing manganese dioxide (MnO2) and graphite powder was obtained from the spent zinc-carbon battery, in which MnO2 was utilized for the oxidative polymerization of pyrrole. The binary graphite/polypyrrole (G/PPy) and ternary MnO2/graphite/polypyrrole (MnO2/G/PPy) nanocomposites were obtained under different reaction conditions, such as hydrochloric acid concentration, MnO2/pyrrole molar ratio, sodium p-toluene sulfonate (p-TSNa)/pyrrole molar ratio, and acid solution volume. The results showed that the electrochemical properties of the G/PPy nanocomposites were better than those of the MnO2/G/PPy. Under the optimized preparation condition (100mL of 1.5mol/L HCl with 0.03mol/L pyrrole, and MnO2/pyrrole/p-TSNa molar ratio of 1:1:1), the G/PPy nanocomposite possessed a relatively high Coulombic efficiency, a high electrical conductivity of 20.0S/cm, and the highest specific capacitance of 212.4F/g at 1mV/s scan rate tested by CV, as well as a retention of 89.5% of its original capacitance after 1000 cycles.

Bioleaching of valuable metals from spent lithium-ion mobile phone batteries using Aspergillus niger

In this paper, a bio-hydrometallurgical route based on fungal activity of Aspergillus niger was evaluated for the detoxification and recovery of Cu, Li, Mn, Al, Co and Ni metals from spent lithium-ion phone mobile batteries under various conditions (one-step, two-step and spent medium bioleaching). The maximum recovery efficiency of 100% for Cu, 95% for Li, 70% for Mn, 65% for Al, 45% for Co, and 38% for Ni was obtained at a pulp density of 1% in spent medium bioleaching. The HPLC results indicated that citric acid in comparison with other detected organic acids (gluconic, oxalic and malic acid) had an important role in the effectiveness of bioleaching using A. niger. The results of FTIR, XRD and FE-SEM analysis of battery powder before and after bioleaching process confirmed that the fungal activities were quite effective. In addition, bioleaching achieved higher removal efficiency for heavy metals than the chemical leaching. This research demonstrated the great potential of bio-hydrometallurgical route to recover heavy metals from spent lithium-ion mobile phone batteries.

Manufacturing conductive polyaniline/graphite nanocomposites with spent battery powder (SBP) for energy storage: A potential approach for sustainable waste management

A potential approach for sustainable waste management of the spent battery material (SBM) is established for manufacturing conductive polyaniline (PANI) nanocomposites as electrode materials for supercapacitors, following the principle of “What comes from the power should be used for the power”. The ternary nanocomposites (G/MnO2/PANI) containing PANI, graphite powder (G) and remanent MnO2 nanoparticles and the binary nanocomposites of polyaniline and graphite powder (G/PANI) are synthesized by the chemical oxidative polymerization of aniline in hydrochloric aqueous solution with the MnO2 nanoparticles in the spent battery powder (SBP) as oxidant. The G/PANI sample, which was prepared with MnO2/aniline mole ratio of 1:1 with 1.0mL aniline in 50mL of 1.0molL−1 HCl, exhibits the electrical conductivity of 22.22Scm−1, the highest specific capacitance up to 317Fg−1 and the highest energy density of 31.0 Wh kg−1, with retention of as high as 84.6% of its initial capacitance after 1000 cycles, indicating good cyclic stability.

Leaching kinetics of spent nickel–cadmium battery in sulphuric acid

Acid leaching process for recovering nickel and cadmium from spent Ni–Cd batteries consumes concentrated acid solution and operate at quite high temperature. The present paper reports improved nickel and cadmium recoveries in sulphuric acid leaching of Ni–Cd battery powder at relatively lower temperatures. The spent Ni–Cd battery powder containing about 69% Ni, 15% Cd and 0.94% Fe was leached in sulphuric acid varying the parameters viz., acid concentration, time, temperature and hydrogen peroxide addition. Dissolution of various nickel and cadmium phases present in Ni–Cd battery powder was investigated by XRD analysis. The kinetics data conformed well to the shrinking core model and the dissolution rate was found to be controlled by surface chemical reaction. The leaching mechanism was further established by characterizing the leach residues for phase composition and morphology. The novelty of the present study was high recovery of nickel (96%) and cadmium (99.5%) by leaching of spent Ni–Cd batteries using dilute sulfuric acid (10vol.%) at moderate temperature (328K) showing potential for scale up trails. The leach liquor obtained in present study contained about 6–7g/dm3 Cd2+, 26–28g/dm3 Ni2+ and up to 0.34g/dm3 Fe3+, and can be subjected to suitable purification and separation technique to recover pure cadmium and nickel metals/compounds.

Facile Preparation of MnO2/Graphene Nanocomposites with Spent Battery Powder for Electrochemical Energy Storage

A conception of “waste from the power should be used for the power” was established for sustainable energy development in the present work. Series of MnO2/graphene nanocomposites have been prepared via a facile physical mixing method as the electrode materials for supercapacitors with the spent battery powder (SBP) as raw material, which was obtained from the spent Zn-MnO2 acidic dry batteries via simple processing. The structure and morphology of the resulting composites were characterized by FT-IR, Raman, XRD, TEM, and SEM. The electrochemical tests showed that the as-obtained SBP had low impedance and excellent cyclic stability of retaining 100% of its initial capacitance after 1000 cycles. After the incorporation of the carbon substrates (graphene oxide (GO) or reduced graphene oxide (rGO)), the capacitance was enhanced more than 2 times the original SBP (66 F/g), which can be attributed to the synergistic effect of the carbon materials and the metal oxide. The present work would lead to new insight i...

Bioleaching of heavy metals from spent household batteries using Acidithiobacillus ferrooxidans: Statistical evaluation and optimization

In this study, spent batteries were selected from municipal waste for bioleaching and extraction of their heavy metals. The bioleaching of nickel, cadmium, and cobalt from Ni–Cd and NiMH batteries was done using Acidithiobacillus ferrooxidans, a resistant strain used for bioleaching. The adaptation process was successful and the solid-to-liquid ratio reached 10g/L (battery powder weight/volume of medium). A Box–Behnken design of response surface methodology (RSM) was used to investigate the effects of initial pH, powder size, and initial Fe3+ concentration on the percentage of metals recovered. The proposed statistical method was used to accurately evaluate the interactions of the factors and their effects on the recovery efficiency of nickel, cadmium and cobalt during bioleaching. Under the specified conditions, up to 99% recovery was observed for each metal, confirming that A. ferrooxidans is an effective toxin resistant microorganism for bio-recovery of heavy metals. Decreasing the initial pH and particle size and increasing the initial Fe3+ concentration led to maximum recovery for nickel and cobalt; while the optimum condition for cadmium was different for Ni and Co. To maximize simultaneous extraction of three metals, the optimum value for initial pH, particle size and initial Fe3+ concentration were obtained 1, 62μm and 9.7g/L, respectively. Under these conditions, the recoveries predicted by the software (Design Expert version 7.1.4) were 85.6% for Ni, 66.1% for Cd, and 90.6% for Co. These results were confirmed using a verification experiment at optimum condition, which calculated 87%, 67%, and 93.7% for Ni, Cd and Co, respectively. Due to the distinct chemical characteristics of Cd in contrast with Ni and Co, its recovery in the optimal condition for simultaneous recovery was decreased; in the other words; Cd recovery was higher when it was the sole target for extraction.