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:
Nov. 25, 2003
Filed:
May. 01, 2001
Gopalakrishnan Sethuraman, East Amherst, NY (US);
Claudette Brown, Lackawanna, NY (US);
Ronald S. Finkelstein, East Amherst, NY (US);
National Gypsum Properties LLC, Charlotte, NC (US);
Abstract
A method of producing calcium sulfate &agr;-hemihydrate is disclosed, including the steps of exposing a mixture including a calcium sulfate form selected from the group consisting of calcium sulfate dihydrate, calcium sulfate &bgr;-hemihydrate, water-soluble calcium sulfate anhydrite, and mixtures thereof, water, and a crystallization catalyst, to microwave radiation to produce calcium sulfate &agr;-hemihydrate; and separating at least a portion of the calcium sulfate &agr;-hemihydrate to provide a solid comprising calcium sulfate &agr;-hemihydrate and a filtrate and/or remainder that can be recycled to provide at least one of a calcium sulfate form, water, a crystallization catalyst, a crystal habit modifier, and a surfactant for use in production of additional &agr;-hemihydrate.