Abstract
Overall environmentally sound technology development for the waste permanent magnets (PMs) processing for the recovery of the rare earths. • The present research and development is concern to recover the rare earths from waste permanent magnets leach liquors. • From this study appropriate experimental condition for crowding studies were optimized. • Based on crowding effect, to enrich the as maximum as separation of rare earths each other. • Extraction isotherm was constructed for dysprosium. • Maximum extraction and predicted the A/O 1, 2 and 3 ratios requires 3, 5 and 8 extraction stages. An environmentally sound process was investigated as feasible to extract and separate rare earths from the synthetic leach liquors prepared based on waste permanent magnets composition analogs. Solvent extraction methods were used to screen different extractants to optimize and suggest the proper extraction system to recovery the different rare earth elements (REEs). Various experimental factors, equilibrium pH and impact of the extractant concentration were studied to select the optimum extraction system. Waste permanent magnets were treated in the initial stages with plating separation, sulfuric acid leaching and double salt precipitation. A second leaching process was implemented by hydrochloric acid; the leach liquor was treated by hydrometallurgy processes for the reprocessing and separation of rare earths present. Three phosphorous based commercial extractants Cyanex 272 (bis (2, 4, 4-trimethylpentyl) phosphinic acid), D2EHPA (bis (2, 4, 4-tri-methyl-pentyl) phosphinic acid) and PC 88A (2-ethyl-hexyl-phosphonic acid mono-2-ethyl-hexyl ester) were applied in the present study. Initial experiments suggested that Cyanex 272 is the best reagent for recovery and potential separation between REs, therefore the crowding studies were carried on. From this study appropriate experimental conditions for crowding were optimized to maximize the enrichment of rare earths while separating them.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
