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:
Dec. 10, 2002
Filed:
Feb. 22, 2001
Kenichi Kimizuka, Kanagawa-ken, JP;
Shoichiro Kajiwara, Kanagawa-ken, JP;
Naoki Kogure, Kanagawa-ken, JP;
Takamitsu Tsuruga, Kanagawa-ken, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
An electrolytic production of sodium persulfate in a decreased number of steps with low unit power cost is described. Sodium persulfate is caused to crystallize by the reaction between an anode product and sodium hydroxide. The resulting sodium persulfate slurry is separated into a mother liquor and sodium persulfate crystals which are recovered and dried to obtain product sodium persulfate. In the process of the invention, ammonia liberated in the reaction-type crystallization of sodium persulfate is recovered into a cathode product, which is then neutralized by sodium hydroxide and/or ammonia. The neutralized solution is combined with sodium sulfate recovered from the mother liquor after recovering the sodium persulfate crystals and reused as a part of the starting material for an anolyte feed solution.