Process for manufacturing ultra low consistency alpha- and beta- blend stucco
US7588634B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2006 |
| Grant date | Sep 15, 2009 |
| Priority date | — |
| Expiry date | Jan 16, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B11/032
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process is disclosed for making a blend of alpha- and beta-stucco including a slurry calcination step to produce alpha calcium sulfate hemihydrate followed by a fluidized bed calcination step to produce beta calcium sulfate hemihydrate. The process starts with 50-75% gypsum-containing solids slurry, and then steam calcines the slurry in a first reactor to form partially calcined gypsum slurry which contains calcium sulfate dihydrate and alpha calcium sulfate hemihydrate. The partially calcined slurry is then dewatered. Then the filter cake is fed into a kettle to complete the calcination process by converting the calcium sulfate dihydrate of the filter cake material into beta calcium sulfate hemihydrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.