Advances in sustainable approaches to recover metals from e-waste-A review

Sustainable soil carbon sequestration practices need to be rapidly scaled up and implemented to contribute to climate change mitigation. We highlight that the major potential for carbon sequestration is in cropland soils, especially those with large yield gaps and/or large historic soil organic carbon losses. The implementation of soil carbon sequestration measures requires a diverse set of options, each adapted to local soil conditions and management opportunities, and accounting for site-specific trade-offs. We propose the establishment of a soil information system containing localised information on soil group, degradation status, crop yield gap, and the associated carbon-sequestration potentials, as well as the provision of incentives and policies to translate management options into region- and soil-specific practices.

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Towards a global-scale soil climate mitigation strategy.

Precious metals are widely applied in many industry fields due to their excellent corrosion resistance, good electrical conductivity and high catalytic activity. However, the reserves of precious metals falls short of the production globally. The rapid generation of end-of-life products has become the significant resources of precious metals. Among these products, electronic waste (e-waste) and spent catalysts are more concentrated since they account for over 90% of precious metals in industry. This article provides an overview of various technologies on the recovery of precious metals from e-waste and spent catalysts. It shows that recycling technologies have been significantly improved in recent years. The recycling processes have transferred from leaching by aqua regia, cyanide and chlorine in acid solution to less pollution agents leaching. Environment-oriented technologies have been raised great attention in precious metals recycling. The advantages and environmental impacts of these recycling technologies have been discussed in detail. However, there are still some challenges for future promotion. In order to achieve the environment-friendly and sustainable recycling for precious metals with high recovery rate, several considerations have been proposed.

Recovery of precious metals from electronic waste and spent catalysts: A review

With the increasing market share of lithium-ion battery in the secondary battery market and their applications in electric vehicles, the recycling of the spent batteries has become necessary. The number of spent lithium-ion batteries grows daily, which presents a unique business opportunity of recovering and recycling valuable metals from the spent lithium-ion cathode materials. Various metals including cobalt, manganese, nickel, aluminum, and lithium can be extracted from these materials through leaching with chemicals such as hydrochloric acid ( HCl ), nitric acid ( HN O 3 ), sulfuric acid ( H 2 S O 4 ), oxalate ( H 2 C 2 O 2 ), DL-malic acid ( C 4 H 5 O 6 ), citric acid ( C 6 H 8 O 7 ), ascorbic acid ( C 6 H 8 O 6 ), phosphoric acid ( H 3 P O 4 ) or acidithiobacillus ferrooxidans. This paper provides a comprehensive review on the available hydrometallurgical technologies for recycling spent lithium-ion cathode materials. The recycling processes, challenges and perspectives reported to date and recycling companies in the market are summarized. To accelerate the development of battery recycling technology toward commercialization, some potential research directions are also proposed in this paper.

A review of recycling spent lithium-ion battery cathode materials using hydrometallurgical treatments

Electric car battery: An overview on global demand, recycling and future approaches towards sustainability.

Palladium finds a remarkable use in electronic devices and catalysts; therefore, an efficient and complete recovery from the containing secondary materials assumes a great relevance. The present paper discusses recovery of palladium (Pd) contained in monolithic ceramic capacitors from waste printed circuit boards (PCBs) of electrical and electronic equipment by hydrometallurgical techniques. Samples, after a milling step, were leached by aqua regia varying the operative conditions. Parameters such as lixiviant concentration, solid/liquid ratio and temperature were investigated. Pd was separated from the leach solution by solvent extraction using Aliquat 336 as an extractant in limonene. This solvent was studied as alternative to the usual ones because it is a renewable organic diluent, with low-toxicity and easily available. After the extraction the organic phase was treated with sodium borohydride to precipitate metallic palladium obtaining a recovery rate of 83% with a purity grade of 98.8%. Based on the results of the present study, a process flow sheet was proposed for industrial implementation.

Palladium recovery from monolithic ceramic capacitors by leaching, solvent extraction and reduction

In this paper the most recent advances in lithium iron phosphate batteries recycling are presented. After discharging operations and safe dismantling and pretreatments, the recovery of materials fr...

Lithium iron phosphate batteries recycling: An assessment of current status

A comprehensive characterization of End-of-Life mobile phones for secondary material resources identification.

Bromine and chlorine are almost ubiquitous in waste of electrical and electronic equipment (WEEE) and the knowledge of their content in the plastic fraction is an essential step for proper end of life management The aim of this study is to compare the following analytical methods: energy dispersive X-ray fluorescence spectroscopy (ED-XRF), ion chromatography (IC), ion-selective electrodes (ISEs), and elemental analysis for the quantitative determination of chlorine and bromine in four real samples taken from different WEEE treatment plants, identifying the best analytical technique for waste management workers Home-made plastic standard materials with known concentrations of chlorine or bromine have been used for calibration of ED-XRF and to test the techniques before the sample analysis Results showed that IC and ISEs, based upon dissolution of the products of the sample combustion, have not always achieved a quantitative absorption of the analytes in the basic solutions and that bromine could be underestimated since several oxidation states occur after combustion Elemental analysis designed for chlorine determination is subjected to strong interference from bromine and required frequent regeneration and recalibration of the measurement cell The most reliable method seemed to be the non-destructive ED-XRF Calibration with home-made standards, having a similar plastic matrix of the samples, enabled us to carry out quantitative determinations, which have been revealed to be satisfactorily accurate and precise In all the analyzed samples a total concentration of chlorine and/or bromine between 06 and 4 w/w% was detected, compromising the feasibility of a mechanical recycling and suggesting the exploration of an alternative route for managing these plastic wastes

https://www.mdpi.com/2071-1050/8/11/1107/pdf

Characterization of some real mixed plastics from weee: A focus on chlorine and bromine determination by different analytical methods

In this paper, a review of the most recent technologies for indium recovery from waste flat panel displays is provided. Differently from the other fractions obtained after primary dismantling (such...

Stefano Pucciarmati

Papers

Palladium recovery from monolithic ceramic capacitors by leaching, solvent extraction and reduction

Lithium iron phosphate batteries recycling: An assessment of current status

A comprehensive characterization of End-of-Life mobile phones for secondary material resources identification.

Characterization of some real mixed plastics from weee: A focus on chlorine and bromine determination by different analytical methods

Recent developments on recycling end-of-life flat panel displays: A comprehensive review focused on indium