A green and efficient process for the stepwise extraction of Cu, Ni, Co, Mn, and Li from hazardous waste with a novel solvent extraction system of D2EHPA-NNPA

Abstract

As the production of electric vehicles and lithium-ion batteries continues to rise, concerns over resource scarcity and supply shortages of critical metals, including Cu, Ni, Co, Mn, and Li, have become increasingly urgent. To address these concerns and promote environmental protection, there is a growing demand for the recycling of hazardous waste containing these critical metals as secondary resources. Therefore, this paper proposes a novel synergistic solvent extraction system of D2EHPA-NNPA, which fills a gap in the lack of a suitable extraction system for the hydrometallurgical industry of secondary resources containing Cu, Ni, Co, Mn, and Li. With the specific extraction sequence of D2EHPA-NNPA, a novel process has been designed and proposed for the stepwise extraction of Cu, Ni, Co, Mn, and Li from secondary resources, which significantly simplifies process flows while avoiding cross-contamination of the extractants and the production of industrial wastewater. Furthermore, the proposed “extraction-scrubbing-stripping” process has been investigated from both macroscopic and microscopic perspectives, demonstrating that the novel synergistic solvent extraction system of D2EHPA-NNPA is a viable option for industrial applications to promote a circular economy and achieve sustainability objectives.