Recovery of neodymium/didymium values from bastnaesite ores
AssigneeRhone-Poulenc Chimie
InventorsAlain Leveque, Jean-Luc Le Loarer
Life of this patent
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Abstract
Neodymium or didymium values are selectively recovered from bastnaesite ores, essentially to the exclusion of cerium and trace amounts of thorium, by (i) calcining the bastnaesite ore, (ii) selectively leaching the calcined bastnaesite with an aqueous solution of nitric acid to solubilize therein neodymium and trivalent rare earth values, and thereby producing an insoluble residue which comprises cerium and thorium values, (iii) separating the insoluble residue, and (iv) liquid/liquid extracting desired neodymium or didymium values from the nitric acid solution.
Claims19
A process for the recovery of neodymium or didymium values, comprising (i) calcining a bastnaesite ore, (ii) selectively leaching said calcined bastnaesite with an aqueous solution of nitric acid to solubilize therein trivalent rare earth values, wherein the amount of nitric acid used in said leaching is about the stoichiometric equivalent of the amount of trivalent rare earth elements present in said calcined ore, thereby producing a less soluble residue which comprises cerium and thorium values, (iii) separating said insoluble residue, and (iv) liquid/liquid extracting desired neodymium or didymium values from said nitric acid solution.
Dependencies are inferred from the claim text.