Calcium sulfate hemihydrate treatment process

A process for treating beta calcium sulfate hemihydrate comprising:

• a. providing a quantity of beta calcium sulfate to a pressure chamber at an initial plaster temperature;
• and
• b. providing steam at an initial steam temperature to the pressure chamber to reach a pressure above atmospheric pressure in the pressure chamber;
• wherein the initial plaster temperature, initial steam temperature, and pressure are selected such that during steps a) and b) less than 2% of the beta calcium sulfate hemihydrate is converted to calcium sulfate anhydrite, and the water demand of the beta calcium sulfate hemihydrate is reduced by at least 3%.

A process for treating beta calcium sulfate hemihydrate comprising:

• a. providing a quantity of beta calcium sulfate to a pressure chamber at a temperature of between 120° C. and 190° C.;
• b. providing steam at a temperature of between 115° C. and 195° C. to the pressure chamber to reach a pressure of between 10 psig and 200 psig in the pressure chamber;
• and
• c. maintaining the pressure in the pressure chamber at between 10 psig and 200 psig for between 5 and 900 seconds.