METHOD FOR PROCESSING SCRAP OF PERMANENT MAGNETS CONTAINING RARE-EARTH ELEMENTS Russian patent published in 1997 - IPC

FIELD: non-ferrous metallurgy. SUBSTANCE: scrap and wastes resulting from production of permanent magnets containing rare earths are subjected to heat treatment at 80-700 C, followed by dissolving them in nitric acid. Sum total of rare earths contained in resulting 0.4-3.0 M nitric acid solution is extracted into organic phase. Latter is used as starting liquor for isolating from it neodymium by extracting other rare earths using tributylphenyl (TBP) as extractant. Neodymium nitrate solution thus-obtained contains less than 0.05 wt. % other rare earths, neodymium recovery from scrap being at least 95%. Other rare earths are subjected to re-extraction from organic phase to thereby form concentrate containing 60-70% samarium. As aqueous phase during separation of neodymium from other rare earths, proposed method employs liquor obtained after washing organic phase with nitric acid or with portion of re-extract containing rare-earth elements. EFFECT: method permits to solve urgent problem of utilization of high-value scrap and wastes containing rare earths. 5 cl, 2 dwg