Spent Alkaline Batteries Research Articles

Modeling and optimization of synergistic effect of Cyanex 302 and D2EHPA on separation of zinc and manganese

A model was developed to predict the synergistic effect of D2EHPA and Cyanex 302 on co-extraction of zinc and manganese. The experimental data of zinc and manganese extraction in pH range of 1–5, temperature of 23, 40 and 60 °C and different organic phase composition (D2EHPA and Cyanex 302) were used to propose correlations of distribution coefficients of zinc and manganese by multiple linear regression. The abilities of the model were examined by applying a case study on separation of zinc and manganese from spent alkaline battery by extraction. Effect of pH, temperature, extractant composition and phase volume were considered in the case study. Optimum operating conditions were determined for a multi-stage extraction column using the genetic algorithm as the optimization routine. These optimum operating conditions, including pH, extractant composition, temperature and phase volumetric ratio, were reported for an extraction unit with one, two, three and four equilibrium stages.

Production of nickel sulfate single crystals in processing of nickel oxide electrodes of alkaline batteries

[NiSO4(H2O)n] single crystals were grown by slow cooling and evaporation of a solution for sulfuric acid leaching of the active paste of a nickel oxide electrode from a spent alkaline battery. The crystals were studied by X-ray phase analysis in two measurement configurations (transmission and Bragg-Brentano focusing).

An investigation of zincite from spent anodic portions of alkaline batteries: An industrial mineral approach for evaluating stock material for recycling potential

The mineralogy of anodic portions of spent alkaline batteries from a leading brand (Duracell) that had been equilibrated in ambient air for approximately 4 months was investigated to determine if material generated from this low energy process may be suitable stock material for recycling. Powder X-ray diffraction (XRD) identified the bulk of the ambient air oxidized anodic material as zincite (ZnO). Scanning electron microscopy investigation indicates a variety of textures of zincite are present with euhedral hexagonal prisms being the most common crystal form. Energy dispersive spectroscopy (EDS) analysis indicates that there are no minor amounts of Mn within the zincite. Transmission electron microscopy investigation indicates a variety of textures exist in the <2 μm size fraction including near euhedral prismatic crystals, crystals with step-fashion terminations and indentations, heavily corroded zincite and near amorphous aggregates of anastomozing zinc oxide. Impurities in the <2 μm size fraction include minor amounts of unidentified mixed sulfate materials and are interpreted as dominantly occurring as thin coatings on zincite particles. Discrete submicrometer-sized spherical and rhomboid particles of Zn–Mn oxides are also common impurities in the <2 μm size fraction but occurr at abundance of <1% by volume. This study provides new baseline information that can be used to develop large scale recycling of zincite from spent alkaline batteries. A promising applications of zincite are numerous, including the development of new solar cell materials. The spent alkaline battery waste stream may serve as promising resource for driving further development of this sector of the economy.

Laboratory study on the leaching potential of spent alkaline batteries

Four different leaching tests were carried out with spent alkaline batteries as an attempt to quantify the environmental potential burdens associated with landfilling. The tests were performed in columns filled up with batteries either entire or cross-cut, using either deionized water or nitric acid solution as leachant. In a first set of tests, the NEN 7343 standard procedure was followed, with leachant circulating in open circuit from bottom to top through columns. These tests were extended to another leaching step where leachant percolated the columns in a closed loop process. Leachate solutions were periodically sampled and pH, conductivity, density, redox potential, sulphates, chlorides and heavy metals (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Tl and Zn) were determined in the samples. The results showed that the total amount of substances leached in tests with cross-cut batteries was higher than with entire ones; zinc and sulphates were the substances found the most in the leachate solutions. In general, the amount of substances dissolved in open circuit is higher than in closed loop due to the effect of solution saturation and the absence of fresh solution addition. Results were compared with metal contents in the batteries and with legal limits for acceptance in landfill (Decision 2003/33/CE and Decree-Law 152/2002). None of the metals were meaningfully dissolved comparatively to its content in the batteries, except Hg. Despite the differences in the experiment procedure used and the one stated in the legislation (mixing, contact time and granulometry), the comparison of results obtained with cross-cut batteries using deionized water with legal limits showed that batteries studied could be considered hazardous waste.

Vitrification for reclaiming spent alkaline batteries

The object of this study is to stabilize spent alkaline batteries and to recover useful metals. A blend of dolomite, limestone, and cullet was added to act as a reductant and a glass matrix former in vitrification. Specimens were vitrified using an electrical heating furnace at 1400 degrees C and the output products included slag, ingot, flue gas, and fly ash. The major constituents of the slag were Ca, Mn, and Si, and the results of the toxicity leaching characteristics met the standards in Taiwan. The ingot was a good material for use in production of stainless steel, due to being mainly composed of Fe and Mn. For the fly ash, the high level of Zn makes it economical to recover. The distribution of metals indicated that most of Co, Cr, Cu, Fe, Mn, and Ni moved to the ingot, while Al, Ca, Mg, and Si stayed in the slag; Hg vaporized as gas phase into the flue gas; and Cd, Pb, and Zn were predominately in the fly ash. Recovery efficiency for Fe and Zn was >90% and the results show that vitrification is a promising technology for reclaiming spent alkaline batteries.

Electrochemical characteristics of manganese oxide/carbon composite as a cathode material for Li/MnO 2 secondary batteries

Electrolytic manganese dioxide (EMD) recovered from a simulated leaching solution of spent alkaline batteries using a modified cyclone cell is tested as a cathode material for Li secondary batteries. An EMD/C(Super P) composite heat-treated at 400 °C after high-energy mechanical milling shows better electrochemical performance than that of pure EMD in terms of cycleability and capacity fading. The electrochemical characteristics of the EMD/C(Super P) composite are investigated by various analytical techniques. The irreversible capacity during the first cycle is mainly due to the formation of a Li 2MnO 3 phase. The carbon composite also retards the dissolution of Mn during cycling.

Development of Metal Recovery Process from Alkaline Manganese Batteries in Sulfuric Acid Solutions

A process for the recovery of Mn from a waste of spent alkaline batteries using sulfuric acid and hydrogen peroxide has been investigated. The proposed procedure consisted of mechanical separation of metal-containing particles and a leaching process. The effects of leaching agent, reaction temperature, time and pulp density for the leaching were also examined. Crushing and sieving of the spent batteries resulted in satisfactory separation of particle size from the waste. 99% Zn and 97% Mn were successfully extracted from the spent battery powder by the leaching at 60°C for 60 min with the addition of hydrogen peroxide as a reducing agent. The hydrogen peroxide addition led to almost doubling Mn extraction compared to without it.

Analysis of a hydrometallurgical route to recover base metals from spent rechargeable batteries by liquid–liquid extraction with Cyanex 272

A hydrometallurgical route is proposed to recover zinc and manganese from spent alkaline batteries in order to separate base metals such as nickel, copper, aluminium, cadmium, lithium and cobalt which constitute the main metallic species of spent NiCd, NiMH and Li-ion rechargeable batteries. The route comprises the following main steps: (1) sorting batteries by type, (2) battery dismantling to separate the spent battery dust from plastic, iron scrap and paper, (3) leaching of the dust with sulphuric acid and (4) metal separation by a liquid–liquid extraction using Cyanex 272 (bis-2,4,4-trimethylpentyl phosphinic acid) as extractant. The metal content of NiCd, NiMH and Li-ion batteries from three distinct manufacturers has been evaluated. A factorial design of experiments was used to investigate the leaching step using operational variables such as temperature, H 2SO 4 concentration, S/L ratio and H 2O 2 concentration. Analysis of metal separation by the liquid–liquid extraction with Cyanex 272 identified a pH 1/2 2.5–3.0 for zinc and aluminium, pH 1/2 4.0–4.5 for manganese, cadmium, copper and cobalt, pH 1/2 6.5 for nickel and pH 1/2 8.0 for lithium. These results indicate that batteries must be previously sorted by type and treated separately. In addition, data fitting to an equilibrium model proposed for the reactive test system by the European Federation of Chemical Engineering (EFChE) have indicated that MR 2(RH) 2 and MR 2 complexes (where M = Zn, Mn, Co, Cd and Cu) co-exist in the organic phase with Cyanex 272 depending on the loading conditions. The route has been found technically viable to separate the main metallic species of all batteries considered in this study.

Development of a hydrometallurgical route for the recovery of zinc and manganese from spent alkaline batteries

A hydrometallurgical route is proposed in this paper for the selective separation of zinc and manganese from spent alkaline batteries. The recycling route comprises the following steps: (1) batteries dismantling to separate the spent batteries dust from other components (iron scraps, plastic and paper), (2) grinding of the batteries dust to produce a black homogeneous powder, (3) leaching of the powder in two sequential steps, “neutral leaching with water” to separate potassium and produce a KOH solution, followed by an “acidic leaching with sulphuric acid” to remove zinc and manganese from the powder, and (4) selective precipitation of zinc and manganese using the KOH solution (pH around 11) produced in the neutral leaching step. For the acidic leaching step, two alternative routes have been investigated (selective leaching of zinc and total leaching) with regard to the following operational variables: temperature, time, sulphuric acid concentration, hydrogen peroxide concentration and solid/liquid ratio. The results obtained in this study have shown that the proposed route is technically simple, versatile and provides efficient separation of zinc and manganese.

Recovery of zinc and manganese from spent alkaline batteries by liquid–liquid extraction with Cyanex 272

A hydrometallurgical route based on the liquid–liquid extraction technique using Cyanex 272 as extractant is investigated for the selective separation of metal values, in particular, zinc and manganese from spent alkaline batteries. The recycling route consists of following steps: (1) cryogenic dismantling of the spent batteries, (2) pre-treatment of the internal material consisting of drying, grinding and screening steps in order to produce a dry homogeneous powder, (3) leaching of the powder with sulphuric acid and (4) metal separation by liquid–liquid extraction. Bench scale experiments have shown that zinc and manganese are easily separated (ΔpH 1/2≈2.0) using 20% (v/v) Cyanex 272 dissolved in Escaid 110 at 50 °C. Therefore, the proposed route can treat residues from both zinc–carbon and alkaline batteries because metal composition of these batteries is quite similar. The metal content of other batteries such as Ni–Cd and nickel-metal hydride (NiMH) has been also determined in order to include them in future investigations.

Characterization of used alkaline batteries powder and analysis of zinc recovery by acid leaching

This paper discusses the spent alkaline batteries characterization and leaching stage experiments results with sulfuric acid as leachant, as part of a complex system, involving purification and electrolytic stages, aiming the Zn recovery. After dismantling batteries by mineral processing techniques, the black powder sample produced was submitted to X-ray diffraction and atomic absorption spectrophotometry in order to identify its composition. Batch laboratory experiments were conducted for acid leaching procedure to determine appropriate leaching conditions from the viewpoint of maximum zinc extraction. On these tests an amount of dry powder was added to sulfuric acid at different conditions and after leaching and filtration, the aqueous solutions were submitted to atomic absorption spectrophotometry analysis to verify the Zn content.

Oil reclaimer : US Patent 3 879 264 (22 April 1975)

The object of this study is to stabilize spent alkaline batteries and to recover useful metals. A blend of dolomite, limestone, and cullet was added to act as a reductant and a glass matrix former in vitrification. Specimens were vitrified using an electrical heating furnace at 1400 °C and the output products included slag, ingot, flue gas, and fly ash. The major constituents of the slag were Ca, Mn, and Si, and the results of the toxicity leaching characteristics met the standards in Taiwan. The ingot was a good material for use in production of stainless steel, due to being mainly composed of Fe and Mn. For the fly ash, the high level of Zn makes it economical to recover. The distribution of metals indicated that most of Co, Cr, Cu, Fe, Mn, and Ni moved to the ingot, while Al, Ca, Mg, and Si stayed in the slag; Hg vaporized as gas phase into the flue gas; and Cd, Pb, and Zn were predominately in the fly ash. Recovery efficiency for Fe and Zn was >90% and the results show that vitrification is a promising technology for reclaiming spent alkaline batteries.