ASSESSMENT OF VARIOUS PROCESSES FOR RARE EARTH ELEMENTS RECOVERY (I): A REVIEW

摘要

In the last few decades, development in the field of rare earth elements (REE) outside China were almost halted due to import of these elements from China. Specialized technologies, equipment, and engineering know-how were allowed to lapse. Since 2009, with a tightening of the export of these elements from China and their reduced availability, other countries have started to look for and develop alternative sources of REE. In this paper, various technologies to extract and recover REE from minerals such as bastnasite, xenotime, and monazite are briefly reviewed. All process steps from leaching and/or decomposition in sulfuric acid, sodium hydroxide, nitric acid, and hydrochloric acid to REE recovery from leachate and separation of these elements in pure form are discussed with an emphasis on the engineering and equipment aspects of process plants required for each flowsheet.