The amount of spent lithium-ion batteries has grown dramatically in recent years, and the development of a recycling process for spent lithium-ion batteries is necessary and urgent from the viewpoi...

Hydrometallurgical Processes for Recycling Spent Lithium-Ion Batteries: A Critical Review

Energy and environmental aspects in recycling lithium-ion batteries: Concept of Battery Identity Global Passport

Porphyry ores and E-wastes/WEEE are two of the most important copper-bearing materials on the planet. Over 60% of world copper output comes from porphyry copper ores while E-waste(s) is globally the largest copper-bearing waste category since the 1980s. They also contain critical elements for low-carbon technologies essential in the clean energy transition's success. In this review, a critical analysis of ore distribution/processing, metal extraction, E-waste generation and E-waste recycling is presented, focusing on identifying challenges and how to address them with emerging technologies and sustainable socio-environmental strategies. Access to ore deposits is a major hurdle for mine development while the absence of a consistent E-waste classification and legislation, including poor collection rates, remains serious problems in E-waste recycling. As lower grade porphyry ores are exploited, difficulties in processing/extraction due to mineralogical complexities, very fine particles and the generation of “dirty” concentrates will become more prevalent. For E-wastes recycling, current trends are to develop smaller, more mobile, and eco-friendly hydrometallurgical alternatives to pyrometallurgy that can handle localised compositional and feed variabilities. Finally, more sustainable mine waste management strategies, including better LCIA tools with spatial and temporal dimensions, are needed to limit socio-environmental impacts of resources exploitation and maintain the sector's SLO.

Copper and critical metals production from porphyry ores and E-wastes: A review of resource availability, processing/recycling challenges, socio-environmental aspects, and sustainability issues

In recent years, recovery of metals from electronic waste within the European Union has become increasingly important due to potential supply risk of strategic raw material and environmental concerns. Electronic waste, especially a mixture of end-of-life electronic products from a variety of sources, is of inherently high complexity in composition, phase, and physiochemical properties. In this research, a closed-loop hydrometallurgical process was developed to recover valuable metals, i.e., copper and precious metals, from an industrially processed information and communication technology waste. A two-stage leaching design of this process was adopted in order to selectively extract copper and enrich precious metals. It was found that the recovery efficiency and extraction selectivity of copper both reached more than 95% by using ammonia-based leaching solutions. A new electrodeposition process has been proven feasible with 90% current efficiency during copper recovery, and the copper purity can reach 99.8 wt %. The residue from the first-stage leaching was screened into coarse and fine fractions. The coarse fraction was returned to be releached for further copper recovery. The fine fraction was treated in the second-stage leaching using sulfuric acid to further concentrate precious metals, which could achieve a 100% increase in their concentrations in the residue with negligible loss into the leaching solution. By a combination of different leaching steps and proper physical separation of light materials, this process can achieve closed-loop recycling of the waste with significant efficiency.

A Cleaner Process for Selective Recovery of Valuable Metals from Electronic Waste of Complex Mixtures of End-of-Life Electronic Products.

The current replacement of electronic products is speeding up, resulting in a growing number of e-waste. Electronic waste, especially waste print circuit boards contain large amounts of copper, which not only bring greater ecological threat, but also cause a serious waste of copper resources. Therefore, the study on clean, effective copper leaching technology has a very important practical significance to reduce environmental hazards of waste print circuit board and resources recycling. Hydrometallurgical is a better technology for recycling copper from waste print circuit boards. In this article, hydrometallurgical copper recovery system is divided into four categories: acid leaching, ammonia - ammonium leaching, chloride leaching, as well as other ways of leaching. The advantages and disadvantages of leaching of copper system are analyzed in the process of copper resource utilization. Studies abound on recycling copper from copper-containing waste with citric acid and other complexing agents as the leaching reagent, but studies on recycling copper from waste print circuit boards are rarely reported, which can be used for reference. The trends of the research are using environmentally friendly reagent as leaching agent, selecting the appropriate leaching solution at a certain temperature and pressure and optimizing the subsequent separation procedure. Recycling of waste gas and waste leachate generated in the hydrometallurgical processcan further reduce chemical costs and meet increasingly exacting environmental requirements.

Current Status and Future Perspective of Recycling Copper by Hydrometallurgy from Waste Printed Circuit Boards

The paper concerns a hydrometallurgical method for selective recovery of copper from low-grade electric and electronic wastes. The following consecutive stages were proposed: smelting of the scraps to produce Cu–Zn–Ag alloy, leaching of the alloy in ammoniacal solution, and selective copper electrowinning. Cu–Zn–Ag alloy was a polymetallic and five-phase system. It was leached in chloride, carbonate, sulfate and thiosulfate solutions. This resulted in the separation of the metals, wherein metallic tin and silver as well as lead salts remained in the slimes, while copper and zinc were transferred to the electrolyte. Copper was selectively recovered from the ammoniacal solutions by the electrolysis, leaving zinc ions in the electrolyte. The best conditions of the alloy treatment were obtained in the ammonia–carbonate system, where the final product was copper of high purity (99.9 %) at the current efficiency of 60 %. Thiosulfate solution was not applicable for the leaching of the copper alloy due to secondary reactions of the formation of copper(I) thiosulfate complexes and precipitation of copper(I) sulfide, both inhibiting dissolution of the metallic material.

/pdf/ammoniacal-leaching-and-recovery-of-copper-from-alloyed-low-3nlbuqrj7h.pdf

Ammoniacal leaching and recovery of copper from alloyed low-grade e-waste

Present work reports on the results of the electrochemical growth of self-ordered zirconia nanotubes formed in aqueous Na2SO4 + HF and nonaqueous electrolytes with glycerol addition. Anodization process was carried out in this inorganic water-based mixture with constant pH = 2.5 and in the voltage range from 5 to 60 V. Similar experiments were repeated in an organic glycerol-based electrolyte with the voltage equal to 20 V and with variable glycerol concentration. All experiments were conducted at constant room temperature. The tube diameter dependence on the voltage of anodization process in an inorganic electrolyte was derived. It was found that when glycerol addition to water electrolyte was used, it takes more time to produce long zirconia nanotubes. However, they do not collapse as the similar structure of the same length formed in aqueous electrolyte.

/pdf/synthesis-of-zro2-nanotubes-in-inorganic-and-organic-3533y4jasg.pdf

Synthesis of ZrO2 nanotubes in inorganic and organic electrolytes by anodic oxidation of zirconium

The aim of the present work was to investigate electrochemical behavior of the Ti6Al7Nb alloy in the simulated body fluid (SBF) containing Ca2+, HCO3
 −, and HPO4
 2− ions. At first, optimal conditions necessary for oxide nanotube formation were determined. The experiments were conducted in the 1 M (NH4)2SO4 with 0.5 wt% NH4F electrolyte at room temperature. Anodization of the alloy samples was carried out under variable external voltage U in the range from 10 to 40 V at room temperature. Obtained surface morphology was examined by SEM and X-ray techniques. Nanotube diameter was calculated and correlated with the imposed voltage. Having control over the size of nanotubes, samples with the obtained nanostructures of a chosen diameter were immersed into SBF solution with pH = 7.4 for a fixed period of time. Then, they were removed from the fluid and subjected to the electrochemical investigation. Corrosion current and corrosion potential were determined, and it was found that the best anticorrosion properties were obtained for heat-treated nanotube layer: i
 corr = 39 nA/cm2 and E
 corr = −0.236 V vs Ag/AgCl. Finally, the interaction between the oxide surface and the solution was studied using polarization and electrochemical impedance spectroscopy (EIS) techniques.

/pdf/electrochemical-synthesis-of-oxide-nanotubes-on-ti6al7nb-4vmqh71t7j.pdf

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Using MHTC 96 Setaram high temperature drop calorimeter, partial and integral enthalpies of mixing of liquid alloys were determined in the Ag–Ga, Cu–Ga and in the ternary Ag–Cu–Ga system. The ternary alloys were investigated along two cross-sections at two different temperatures: 1128 K and 1273 K, respectively. Experimental data were used to find ternary interaction parameters by applying the Redlich–Kister–Muggianu model for substitutional solutions, and a full set of parameters describing the concentration dependence of the enthalpy of mixing was derived. The experimental data indicate that the heat of mixing in this system is slightly temperature dependent, at least in the measured temperature range.

Enthalpies of mixing of liquid Ag–Ga, Cu–Ga and Ag–Cu–Ga alloys

Attempts have been made to find the best procedure for the detection of premature battery capacity loss (the so called “PCL”) in AGM-VRLA 48 V batteries operating in telecommunication systems. However, recorded changes in internal resistance and potential did not give clear indications of the beginning of the PCL effect. The obtained correlation between internal resistance and potential derived from used batteries does not show the expected trend in measured parameters. It seems that the application of Electrochemical Impedance Spectroscopy (EIS), which is a faster and non-destructive method, may solve this problem. It is demonstrated that the change in internal resistance (which is an indicator of the state of health (SoH)) can be determined from EIS spectra during continuous operation of 12 V monoblocks in a backup power source of a base transceiver station (BTS).

https://www.mdpi.com/2313-0105/4/4/70/pdf/1

Piotr Handzlik

Papers

Ammoniacal leaching and recovery of copper from alloyed low-grade e-waste

Synthesis of ZrO2 nanotubes in inorganic and organic electrolytes by anodic oxidation of zirconium

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Enthalpies of mixing of liquid Ag–Ga, Cu–Ga and Ag–Cu–Ga alloys

Electrochemical Impedance Spectroscopy and Determination of the Internal Resistance as a Way to Estimate Lead-Acid Batteries Condition