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:
Sep. 04, 1990
Filed:
Nov. 28, 1988
Applicant:
Inventors:
Francinet Cailly, Paris, FR;
Frederic Fabre, Paris, FR;
Assignee:
Rhone-Poulenc Chimie, Courbevoie, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01F / ; C01F / ;
U.S. Cl.
CPC ...
252625 ; 423-3 ; 423 11 ; 423 211 ; 423 215 ; 423-8 ; 423252 ;
Abstract
Thorium and rare earth values are separated from a fluoride concentrate thereof, by decomposing such concentrate with aqueous sodium hydroxide under conditions such that the amount of sodium hydroxide is at least 1.4 times the stoichiometric amount and the initial sodium hydroxide/water ratio in the medium of decomposition ranges from 1 to 40% by weight, whereby a precipitate of thorium hydroxide and rare earth hydroxides is produced, together with a solution of sodium fluoride, and then separating the NaF solution therefrom.