Patent · US Active

Recycling method of dihydrate gypsum from waste gypsum boards

US10947155B2 · kind B2 · utility

1Cited by

2References

3Claims

0Family size

Assignee

TOKUYAMA CORPORATION · JP

Inventors

Shingo Hiranaka · Shunan, JP
Kentaro Matsuo · Hitachinaka, JP
Makoto Kataoka · Hamamatsu, JP

Key dates

Filing date	Oct 22, 2019
Grant date	Mar 16, 2021
Priority date	—
Expiry date	Oct 22, 2039

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC04B28/14
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.