RECOVERY OF RARE EARTH ELEMENTS

摘要

A process for recovering rare earth elements from a composite ore containi ng rare earth elements that includes a monazite group mineral and an apatite mineral, includes pre-leaching the composite ore with an acid so as to substantially dissolve the apatite mineral into the leach liquor and precipitating rare earth elements from the pre- leach liquor. The residue of the pre-leaching step is subjected to an acid bake treatment, followed by a water leach, to produce a water leach liquor rich i n rare earth elements. Impurities including thorium and iron are separated from the water leach liquor by introducing a neutralising additive to the water leach liquor rich in rare earth elements, and rare earth elements are precipitated from the post- neutralisation liquor.