A beneficiation study to recover xenotime minerals from rich-iron-silicate ores

The Yen Phu (YP) rare-earth mine, located in Yen Bai, Vietnam, currently reserves 28,000 tons of total rare earth oxides (TREO) with a TREO grade of about 1.16%. A mineralogy study shows the dominance of iron-oxide- and silicate-bearing minerals in YP ore, whereas xenotime presents as the major rare-earth metal (REM) bearing mineral. Chemical analyses also exhibit a relatively high proportion of heavy rare earth metals (HREMs) at 41.2%, which suggests the high economic value of YP ores. The factors influencing the flotation involving the pH, the depressant, and the collector dosage were first assessed. Then, a beneficiation flowsheet including grinding, wet magnetic separation, and flotation was recommended and practically conducted to enrich the TREO. The proposed process successfully promoted the TREO grade from 1.16% to 29.70% with a high recovery of 80.31% in the REM concentrates, while a tiny loss of TREO was exhibited in the tailing. The chemical analysis of REM concentrates also demonstrated the conservation of REM composition throughout the beneficiation.