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:
Oct. 04, 2016
Filed:
Aug. 08, 2013
Yoshino Gypsum Co., Ltd., Tokyo, JP;
YOSHINO GYPSUM CO., LTD., Tokyo, JP;
Abstract
A process for the continuous modification of dihydrate gypsum includes calcining dihydrate gypsum into hemihydrate gypsum and recrystallizing the hemihydrate gypsum in an aqueous slurry to convert the hemihydrate gypsum into modified dihydrate gypsum of different crystalline form. The aqueous slurry in a recrystallization reaction tank is maintained at a constant temperature under stirring, and a feed rate of the hemihydrate gypsum to the recrystallization reaction tank and a discharge rate of the recrystallized dihydrate gypsum are controlled to substantially equal. Dihydrate gypsum as a starting raw material can be converted into high-purity, modified dihydrate gypsum of large crystals by recrystallizing the starting dihydrate gypsum after it is once calcined into hemihydrate gypsum.