Recovery of Rare Earth Elements from Waste Permanent Magnets Leach Liquors

摘要

The scrap magnet contains significant amounts of rare earth metals such as neodymium, praseodymium, dysprosium, and terbium. In the twenty-first century, faster growing rate of hi-tech industrialization leads to the generation of the secondary wastes across the globe, which is becoming an environmental concern. To resolve the environmental issue vis-a-vis to meet the demand for rare earth metals, this investigation is focused on the development of a suitable process for extraction of Nd, Dy, Pr, and Tb from the scrap permanent magnet using leaching followed by solvent extraction. During leaching, oxidation roasting process was adopted to minimize the dissolution of iron. The resulted leach liquor was subjected to liquid-liquid extraction of Nd, Pr, Dy, and Tb using organophosphorus derivatives reagents. Process optimization followed by extraction isotherm study was carried out to obtain quantitative extraction of these metals from the aqueous media. The crowding effect was further investigated to improve the separation factor of the RE metals and reported.