Rapid-setting gypsum burned

img11 (13)Rapid-setting gypsum burned, not used for construction purposes, is obtained by heating raw gypsum to a temperature of about 200 ° C. The burned plaster is used to make quick-setting alabaster gypsum and quick-setting masonry gypsum. Hydraulic plaster (cement, strichgips, anhydrous gypsum) is obtained by firing certain types of raw gypsum at temperatures above 500 ° C (most preferably at a temperature of 800-1000 ° C), the raw gypsum completely loses water. The degree of grinding of the hydraulic plaster should be this, that the residue on the sieve, o 900 meshes on 1 cm2 did not exceed 30%