Calcium sulphate-based composition and methods of making same
AssigneeG.B. Technologies, LLC
InventorsDanny W. Cox, Robert B. Bruce
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Abstract
Disclosed is an improved alpha calcium sulfate hemihydrate. Methods of producing an improved powdered calcium sulfate hemihydrate (CaSO4·½H2O) [alpha-type] compound are disclosed, at least one method including forming calcium sulfate dihydrate (CaSO4·2H2O) into a briquette under high pressure, calcining the briquette to transform the calcium sulfate dihydrate to calcium sulfate hemihydrate [alpha-type], drying the calcium sulfate hemihydrate [alpha-type] briquette, and optionally grinding the briquette. Also disclosed are methods of producing an improved gypsum plaster including producing the disclosed powdered calcium sulfate hemihydrate [alpha-type] and mixing the powdered calcium sulfate hemihydrate [alpha-type] with water.
Claims40
A method, comprising:
- forming calcium sulfate dihydrate (CaSO4·2H2O) into a briquette a pressure greater than 14 megapascal (MPa);
- calcining the briquette;
- transforming the calcium sulfate dihydrate briquette to a calcium sulfate hemihydrate (CaSO4·½H2O) [alpha-type] (“alpha-hemihydrate”) briquette;
- and
- drying the alpha-hemihydrate briquette.
A calcium sulfate hemihydrate (CaSO4·½H2O) [alpha-type] (“alpha-hemihydrate”) comprising:
- crystals of the alpha-hemihydrate that have grown together to form clusters of the crystals;
- wherein the clusters of crystals have substantially reduced pore volume between the clusters, than the pore volume of alpha-hemihydrate crystals formed from dihydrate briquettes compressed at pressures less than or equal to 14 megapascal (MPa).
A dry, ground calcium sulfate hemihydrate (CaSO4·½H2O) [alpha-type] (“alpha-hemihydrate”) converted from a calcined calcium sulfate dihydrate briquette that was compressed at a pressure of greater than 14 megapascal (MPa);
- wherein the dry, ground alpha-hemihydrate has a water demand of less than 50 milliliters (ml) per 100 grams (g) of dry, ground alpha-hemihydrate.
Dependencies are inferred from the claim text.