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:
Feb. 17, 1981
Filed:
Aug. 07, 1979
Applicant:
Inventors:
Yoshiyuki Kobayashi, Ube, JP;
Tamio Nakamura, Ube, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01F / ;
U.S. Cl.
CPC ...
423465 ;
Abstract
A process of precipitating cryolite from a reaction solution given by mixing a sodium aluminate solution with a fluoride solution containing silica dissolved therein as impurity at reaction temperatures above 60.degree. C. To reduce silica content in the precipitated cryolite, the reaction solution is made to contain carbonate ions, 1-20 g/l as CO.sub.2, by introducing either carbon dioxide gas or a soluble carbonate into the fluoride solution Moreover, ignition loss of the cryolite can be decreased by preheating the sodium aluminate solution to 90.degree. C. or above.