Selective Recovery Of Nickel Research Articles

Selective recovery of Nickel from electroplating rinse bath wastewater by an integrated Donnan Dialysis/precipitation process

ABSTRACT The purpose of this work is to experimentally assess the application of a hybrid process, Donnan Dialysis (DD)/precipitation, for the selective separation and recovery of Nickel ions from Nickel electroplating rinse bath effluent. The primary objectives include facilitating water and Nickel reuse while protecting environmental resources. The separation of Ni (II) via an ion-exchange membrane was investigated experimentally. Operational parameters, such as the type of cation-exchange membrane, initial Nickel (II) concentration, and counter-ion concentration, were systematically studied to understand their impact on the productivity and selectivity of DD process. Simultaneously, the feasibility and efficiency of Ni (II) recovery from the receiver compartment through the precipitation process, forming Ni3(PO4)2, were examined. Results indicate that, under optimal conditions and with an initial Ni (II) concentration of 200 mg/L or less, the removal efficiency reached 90% after 24 hours of dialysis. Significantly, the type of cation-exchange membrane emerged as a crucial factor influencing Ni (II) removal. Additionally, employing PO4 3- as a precipitation reagent in a stoichiometric ratio yielded an excellent Ni recovery performance of 99%. Consequently, the treated effluent (feed compartment) becomes suitable for recycling in a new electroplating operation, while the solution obtained in the receiver compartment can be reused for another DD cycle process after Ni (II) recovery as Ni3(PO4)2. Importantly, this hybrid method produces a valuable Ni3(PO4)2 precipitate of excellent quality.

Selective recovery of nickel from stainless steel pickling sludge with NH3-(NH4)2CO3 leaching system

ABSTRACT The recovery of valuable metals from stainless steel pickling sludge(SSPS) has great economic and environmental benefits. In this study, a new method is proposed for selective recovery of nickel from SSPS by NH3-(NH4)2CO3 ammonia leaching system. The Eh-pH diagram was used to analyze Ni, Fe, Cr leaching behavior during the ammonia leaching process. Nickel can be leached as the complex [Ni(NH3)n]2+, whereas Fe and Cr remain as precipitates in the leaching slag. The effects of NH3·H2O concentration, liquid–solid ratio, reaction temperature, and reaction time on the leaching efficiency of nickel in the ammonia leaching system were analyzed and optimized by single-factor study and response surface analysis, and the kinetics were analyzed. The optimal conditions for Ni leaching were found to be 28.28 min, 54.07 °C, a liquid–solid ratio of 23.7:1, and NH3·H2O concentration of 5.10 mol/L. Each factor had a greater effect on the rate of Ni leaching in the following order: liquid–solid ratio > NH3·H2O concentration > leaching time > leaching temperature. The ammonia leaching recovery system was controlled by chemical reaction and the activation energy was 58.17 KJ/mol. The results of scanning electron microscopy-energy dispersion spectrum (SEM-EDS), x-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) show that the leaching slag was in granular form with agglomerated particles and particle size of approximately 2.8 μm The major components of the leaching slag were Fe(OH)3, Fe2O3, Fe(OH)2, Cr(OH)3, and Cr2O3. Therefore, this study provides a new and effective way of using the resources of SSPS.

Selective recovery of nickel from obsolete mobile phone PCBs

In the present investigation, the selective recovery of nickel from a leach solution of delaminated metal clads from obsolete mobile phone PCBs using the industrial reagent ACORGA M5640 has been studied. As a first step, copper is selectively separated from the mixed metal leach liquor by solvent extraction at pH 2, to leave a nickel-rich raffinate solution. A second stage solvent extraction process conducted at pH 8 then permits recovery of the nickel. Small quantities of zinc and cadmium are also co-extracted. In this study, the conditions for most suitable nickel extraction and stripping have been explored. Results indicate that quantitative extraction of nickel (99.7%) can be achieved using a 1:5 organic (10 vol% extractant in kerosene) to aqueous (pH 8) phase ratio in 60 min. The nickel in the organic phase is readily stripped from the extractant, with more than 95% recovered, along with low levels of zinc (1.7 mg/L) and cadmium (0.6 mg/L), following a 0.5 M hydrochloric acid or 1 M nitric acid strip step. Cyclic usage of the extractant organic layer revealed that its effectiveness to extraction has remained equivalent to the first cycle. Finally, the separation of trace elements such as lead, tin and cadmium from the raffinate of stage 2 solvent extraction is also studied by cementation with zinc powder. The study reveals that the removal of these elements and the generation of pure zinc solution can be obtained by adding 300% excess zinc powder (74 μm) at 50 °C with 500 rpm stirring speed in 60 min. The separation of copper in stage 1, nickel from copper-free aqueous solution in stage 2 and other minor elements from the raffinate of stage 2 solvent extraction ensures the proposed process is sustainable and avoids complexity in the sequential metal recovery processes.

The Separation and Recovery of Nickel and Lithium from the Sulfate Leach Liquor of Spent Lithium Ion Batteries using PC-88A

The present paper deals with the extractive separation and selective recovery of nickel and lithium from the sulfate leachate of cathode scrap generated during the manufacture of LIBs. The conditions for extraction, scrubbing and stripping of nickel from lithium were optimized with an aqueous feed containing Ni and Li using PC-88A. Over 99.6% nickel was extracted with PC-88A in two counter-current stages at O/A=1 and pH=6.5. Effective scrubbing Li from loaded organic was systematically studied with a dilute solution (). The McCabe-Thiele diagram suggests two counter-current scrubbing stages are required at O/A=2/3 to yield lithium-scrubbing efficiency of 99.6%. The proposed process showed advantages of simplicity, and high purity (99.9%) nickel sulfate recovery along with lithium to ensure the complete recycling of the waste from LIBs manufacturing process.

Utilization of nickel slag using selective reduction followed by magnetic separation

In order to utilize slag discarded by nickel plants, the selective recovery of nickel and copper versus iron was investigated by selective reduction, which was achieved by controlling the reduction parameters and magnetic separation process on bench scale. The results show that increasing the basicity (mass ratio of CaO to SiO2) of nickel slag facilitates the enrichment of nickel and copper. The process parameters for selective reduction were optimized as follows: basicity of 0.15, reducing at 1200 °C for 20 min, 5% coal on a dried slag mass base. The grinding-magnetic separation results of reduced briquettes show that concentrate containing 3.25%Ni, 1.20%Cu and 75.26%Fe is obtained and selective enrichment is achieved with a recovery of 82.20%, 80.00% for nickel and copper respectively, while the recovery of iron is only 42.17%. The S and P contents are not reduced obviously and further research may be needed to examine the behaviors of S and P in the process.

Selective recovery of nickel over iron from a nickel–iron solution using microbial sulfate reduction in a gas-lift bioreactor

Process streams with high concentrations of metals and sulfate are characteristic for the mining and metallurgical industries. This study aims to selectively recover nickel from a nickel–iron-containing solution at pH 5.0 using a single stage bioreactor that simultaneously combines low pH sulfate reduction and metal-sulfide formation. The results show that nickel was selectively precipitated in the bioreactor at pH 5.0 and the precipitates consisted of ≥83% of the nickel content. The nickel–iron precipitates were partly crystalline and had a metal/sulfur ratio of 1, suggesting these precipitates were NiS and FeS. Experiments focusing on nickel recovery at pH 5.0 and 5.5 reached a recovery of >99.9%, resulting in a nickel effluent concentration <0.05 μM. The mixed microbial population included known sulfate reducers and acetogens. This study shows that selective metal precipitation in a single stage sulfate reducing bioreactor operated at low pH has the potential to produce metal-sulfides that can be used by the metallurgical industry as a resource for metal production.

Selective recovery of nickel and cobalt from cobalt-enriched Ni–Cu matte by two-stage counter-current leaching

This work presents investigations on the selective recovery of Ni and Co from Ni–Cu matte by two-stage counter-current leaching. The investigations indicated that the sulphuric acid used during leaching can be fully replaced by sulphur. The leaching behavior of nickel and cobalt were determined and the influences of temperature, the amount of sulphur and oxygen pressure on leaching process were also investigated. A pilot plant experiment was carried out to confirm the developed process. It is found that, under two leaching conditions: (1) Ambient pressure leaching: sulphur coefficient = 1.15, T = 85 ± 5 °C and time = 2.5 h with a liquid to solid ratio of 5:1 (i.e., L/S = 5:1), and (2) Elevated pressure leaching: L/S = 5:1, T = 150 ± 5 °C, pressure = 1.45 MPa, air flowrate = 1500 ± 50 N m 3/h and time = 6 h; the achieved recoveries of Ni and Co were >96.02%. The ratio of Cu/Ni is higher than 45 in the resulting residue, which is favorable for effective recovery Cu by simple H 2SO 4 leaching followed by electrowinning step to obtain copper metal. Therefore, the leaching liquor can be used to recover Ni and Co after removal of iron and Cu can be extracted from the residue.

Hazardous wastes assessment, management, and minimization

Hazardous wastes assessment, management, and minimization

Selective Recovery of Nickel and Cobalt from Electromachining Sludge Materials

ABSTRACT The recovery of nickel and cobalt from electromachining sludge in the form of relatively high-purity marketable products has been investigated. The investigation has shown that a series of hydrometallurgical unit operations can be performed to recover nickel and cobalt from electromachining sludge in the form of nickelic hydroxide and cobalt sulfate/cobalt metal, respectively. The recovery unit operations for nickel include high pH cyanide complexation, followed by oxidation and precipitation of nickelic hydroxide. The resultant filtrate can be treated for cobalt concentration and recovery by precipitation of a cobaltous/cobaltic double cyanide salt and cobaltous hydroxide. This concentrated form of cobalt can then be converted to cobalt sulfate by acid baking; then redissolved and electrowon as high purity cobalt metal. Product purity rivals that of conventional multistage solvent extraction processes. First order cost estimation indicates the possibility of excellent return on investment.