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US 10,947,155 B2Granted
Recycling method of dihydrate gypsum from waste gypsum boards
AssigneeTokuyama Corporation
InventorsShingo Hiranaka, Kentaro Matsuo, Makoto Kataoka
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Abstract
Gypsum derived from waste gypsum boards is calcined and converted into gypsum granules including hemihydrate and/or anhydrous type III gypsum. The calcined gypsum granules are dropped into water to prepare a gypsum slurry. Then, dihydrate gypsum particles are crystalized in the slurry. The temperature of the gypsum granules just before being dropped into the water is 90° C. or higher.
Claims3
A method of recycling dihydrate gypsum from waste gypsum boards, the method comprising:
- calcining gypsum derived from waste gypsum boards to convert the gypsum into hemihydrate and/or anhydrous type III gypsum granules;
- dropping the gypsum granules after calcination into water to mix the gypsum granules with water to prepare a gypsum slurry;
- and
- crystalizing dihydrate gypsum particles in the gypsum slurry;
- wherein
- a temperature of the gypsum granules just before being dropped into the water is 90° C. or higher.
3 more elements
Dependencies are inferred from the claim text.