... content, less than 10%; MgO, less than 5%.(2). Gypsum: dihydrate plaster stone or phosphogypsum, sulphur trioxide content, more than 35%.(3 ... : 600KG/m3;(2). Proportion: cement, 8%; Quicklime, 19%; sand, 70%; Gypsum, 3%; aluminium powder, 450g/m3; addictives: 400g/m3.(3). Each ...