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.

Date of Patent:
Nov. 16, 1999

Filed:

Oct. 31, 1996
Applicant:
Inventors:

Hiroshi Fukuta, Shizuoka, JP;

Tsutomu Kakei, Shizuoka, JP;

Tadabumi Tomita, Shizuoka, JP;

Hideki Miwa, Shizuoka, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B44C / ; C01F / ;
U.S. Cl.
CPC ...
216 93 ; 423629 ; 23301 ; 2330 / ; 156 6421 ;
Abstract

The present invention allows the reproduction of a crystalline aluminum hydroxide having a high particle strength and a high purity which can find wide application such as abrasive from a supersaturated sodium aluminate solution which is being recycled in the production of aluminum hydroxide or lithographic printing plate. In a process for the purification of aluminum hydroxide which comprises the hydrolysis reaction of a supersaturated solution of sodium aluminate to crystallize aluminum hydroxide, the improvement which comprises the steps of keeping the temperature of a suspension formed by mixing a mother liquor having a total caustic soda concentration of from 50 to 700 g/l and an aluminum concentration or from 0 to 300 g/l with crystalline aluminum hydroxide at a range of from 10.degree. C. to 200.degree. C. for at least 1 to 48 hours, mixing the suspension with the supersaturated solution of sodium aluminate, and then causing the crystallization reaction at the crystallization reaction temperature.


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