A Novel Method of Recovering Rare Earths from Bayan Obo Rare-Earth Concentrate Under Super-Gravity Field

Abstract

A novel method of effectively recovering rare earths (REEs) from rare-earth concentrate under super-gravity was proposed in this paper. The reconstructions of rare-earth phases in normal gravity and the separation behaviours of REEs under super-gravity were investigated. It was indicated by the results of the mineral phase reconstructions that the rare-earth phases were transformed from original minerals of bastnaesite and monazite into britholite, rare-earth oxide fluoride, rare-earth ferrate and monazite particles at 1423–1523 K, and there was the only solid phase—rare-earth oxide fluoride phase in the sample at 1773 K. In a super-gravity field , all the rare-earth oxide fluoride crystals were overall intercepted by the filter along the super-gravity direction and effectively separated from the slag melts. The mass fractions of ∑ReO and Ce₂O₃ in the separated rare-earth oxide fluoride phase increased to 88.31 and 60.76 wt%, the recovery of ∑ReO and Ce₂O₃ were 90.22 and 95.41%, respectively.