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:
Mar. 17, 1987
Filed:
Jan. 24, 1985
Applicant:
Inventors:
Assignee:
Kasei Optonix, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
C01F / ;
U.S. Cl.
CPC ...
423 211 ; 423263 ;
Abstract
A process for recovering highly pure rare earth oxides from a waste rare earth phosphor containing at least Fe and/or Ca as impurities, which comprises dissolving the waste rare earth phosphor in an excess amount of a strong acid capable of dissolving the waste rare earth phosphor, adding to the solution at a temperature of at least 70.degree. C. oxalic acid in an amount of from 0.3 to 1.8 times the theoretical amount to obtain precipitates of rare earth oxalates, washing the precipitates with warm water having a temperature of at least 50.degree. C. and then baking them.