Processing of xenotime concentrate

Abstract

Xenotime is a rare earth phosphate mineral which is a rich source of yttrium and heavy rare earths. Earlier experimental studies have been carried out in this laboratory on the chemical processing of hand-sorted xenotime obtained from the Bihar region to rare earth oxide intermediates. In addition to the deposits of xenotime in the Bihar region there are large volumes of placer deposits of rare earths containing both monazite and xenotime in the Siri river basin of Madhya Pradesh. Atomic Minerals Division is operating a pilot plant for the beneficiation of rare earths from these Siri river deposits. A low grade (typically analysing 45% light rare earth oxide, 3.4% Y 2O 3 and 2.3% heavy rare earth oxide) and intermediate grade (analysing 18.5% light rare earth oxide, 19.3% Y 2O 3 and 8.7% heavy rare earth oxide) concentrate is routinely being produced. The paper reports experimental studies involving alkali leaching and alkali fusion studies to recover rare earth oxide intermediates from low and intermediate grade deposits from Madhya Pradesh. It has been shown possible to extract almost 95% of rare earths by these processes.