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:
Jul. 07, 2009
Filed:
Dec. 20, 2006
Michael Lawrence Bolind, Ingleside, IL (US);
Michael J. Porter, Akron, IN (US);
Christopher Robert Nelsen, Lindenhurst, IL (US);
Michael Lawrence Bolind, Ingleside, IL (US);
Michael J. Porter, Akron, IN (US);
Christopher Robert Nelsen, Lindenhurst, IL (US);
United States Gypsum Company, Chicago, IL (US);
Abstract
A process is disclosed for making dead burn calcium sulfate anhydrite. The process includes a slurry calcination step to produce calcium sulfate anhydrite followed by removing free water from the anhydrite while avoiding substantial rehydration. Also disclosed are dead burn calcium sulfate anhydrite particles with high aspect ratios, e.g. fibers having an average aspect ratio of at least 4:1, or very fine particle size, e.g., at or below 2 micrometers average, combined with very low water content, e.g., less than 0.5, preferably less than 0.3, wt. % water. These particles are typically useful as fillers.