ALEXANDRIA, Va., Aug. 20 -- United States Patent no. 12,391,613, issued on Aug. 19, was assigned to Tokuyama Corp. (Yamaguchi, Japan).
"Method for reclaiming gypsum from wasted gypsum boards" was invented by Shingo Hiranaka (Shunan, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "Wasted gypsum boards are crushed and heated to convert semi-hydrated gypsum and/or anhydrous type III gypsum, and the obtained semi-hydrated gypsum and/or anhydrous type III gypsum is mixed with gypsum slurry. The gypsum slurry is solid/liquid separated by a filtration device into gypsum particles and filtrate which has passed through the filter cloth of the filtration device. The filtrate is returned into the gypsum slurry. Th...