Adsorption of oxygen and nitrogen by calcium sulphate

Abstract

A study has been made of the adsorption of oxygen and nitrogen by finely divided calcium sulphate and its hydrates. Particular attention has been paid to anhydrous calcium sulphate prepared by the dehydration of calcium sulphate hemihydrate and gypsum in vacuo. It appears that the transformation of γ- to β-calcium sulphate is not necessarily associated with an increase in surface area.

Results obtained by previous workers are discussed in relation to the present findings.