Process for preparing alpha calcium sulfate hemihydrate
US7700066B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 2008 |
| Grant date | Apr 20, 2010 |
| Priority date | — |
| Expiry date | Oct 3, 2028 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01F11/46
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention provides a process for preparing α-calcium sulfate hemihydrate which comprises the following steps: adding aqueous solutions containing sulfate ions and calcium ions to calcium chloride solution with a range of concentration; reacting the mixture of a) at a range of temperature for an appropriate time; filtering and washing the reaction products of b) with a rising solvent to isolate the solid and liquid phases; and d) collecting and drying the solid phase to obtain α-calcium sulfate hemihydrate with high purity; wherein the relationship between the range of the concentration of calcium chloride (y) and the range of the reaction temperature (x) is shown as the following formula: −0.4x5+7.33x4−52.83x3+187.17x2−328.27x+316<y<1.2x5−22x4+158.5x3−561.5x2+984.8x−588 (2<X<5).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.