Recovery Process Development for the Rare Earths from Permanent Magnet Scraps Leach Liquors

The current study deals with the recovery process development for the rare earths (REs), i.e., dysprosium (Dy) and neodymium (Nd), metals from permanent magnet scraps leach liquors. Its main objective is the recovery of the rare earths (Dy and Nd) from permanent magnet scraps (PMSs). Introdutory experiments were carried out to get leach liquor solution: oxidation/roasting, acid leaching, and precipitation methods implemented for PMSs dissolution. The obtained PMSs leach liquor was diluted ten times and used for present study. Di-2-ethylhexyl phosphoric acid (D2EHPA) was used as an extractant for recovery of the REs and kerosene as diluent system. The present study optimized the various experimental parameters such as the time influence on extraction process, influence of pH, extractant concentration, separation factors calculated, scrubbing, stripping, maximum loading capacity of the extractant, and various phase ratios as well as phase ratios influence on present metals separations. Loading capacity of D2EHPA and selective stripping process were developed for targeted metal ions by using various mineral acids such as hydrochloric, sulfuric and nitric acids. The metal content analysis in the aqueous samples was determined with inductively coupled plasma optical emission spectrometer (ICP OES) for sensitive and accurate data.