The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 1994
Filed:
Mar. 19, 1987
Applicant:
Inventors:
Alain Leveque, La Rochelle, FR;
Jean-Luc Le Loarer, La Rochelle, FR;
Assignee:
Rhone-Poulenc Chimie, Courbevoie, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01F / ;
U.S. Cl.
CPC ...
423 211 ; 423 215 ; 423263 ;
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.