Manufacture of gypsum board from FGD gypsum
US4502901A · kind A · utility
16Cited by
4References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 19, 1983 |
| Grant date | Mar 5, 1985 |
| Priority date | — |
| Expiry date | Oct 19, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B11/264
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
By-product gypsum, which is formed during a flue gas desulfurization process, (FGD gypsum) is carefully formed as an aqueous slurry of crystals having a mean particle diameter of between about 35 microns and 80 microns and filtered, which filter cake is substantially completely dried before calcination, without any substantial grinding action, the crystals are then flash calcined to a hemihydrate, then ground, to reduce consistency, and then formed into an aqueous slurry from which a paper-covered gypsum board is formed of superior core quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.