Process for extraction of rare earth elements

摘要

A process for the extraction of rare earth elements, including yttrium, from a rare earth element-bearing ore or concentrate, comprising the steps of leaching the rare earth element-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of from 90° C. to the boiling point of the solution and at an Eh of at least 200 mV. After a liquid/solids separation step, the solution obtained is subjected to steps for removal of iron and for recovery of rare earth elements. Alternatively, rare earth element-bearing ore or concentrate may be leached with sulphuric acid and liquid obtained subjected to extraction of iron and other impurities. Raffinate obtained may be treated with oxalic acid, the precipitate dissolved in hydrochloric acid and subjected to solvent extraction for rare earth elements or the raffinate may be subjected to solvent extraction for removal of rare earth elements and then stripped with hydrochloric acid.

主权项

1. A process for the extraction of at least one rare earth element from a rare earth element-bearing ore or concentrate, comprising the steps of:
a) leaching the rare earth element-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of from 90° C. to the boiling point of the lixiviant and an Eh of at least 200 mV to obtain a leach solution; and b) subjecting the leach solution of step a) to a liquid/solids separation step.