Gypsum is monoclinic mineral, and its main chemical component is calcium sulfate (CaSO4). Natural dihydrate gypsum (CaSO4·2H2O) is also known as raw gypsum, after calcination, grinding can be obtained Beta-type hemihydrate gypsum (CaSO4·1/2H2O), that is, building gypsum, also known as plaster, plaster. If the calcination temperature is 190 degrees C, the model gypsum can be obtained, and its fineness and whiteness are higher than those of plaster. If the gypsum is calcined at 400-500 degrees C or above 800 degrees C, the floor gypsum will be obtained. Its setting and hardening are slower, but its strength, wear resistance and water resistance are better than ordinary building gypsum. Gypsum is usually white, colorless, colorless transparent crystal known as transgypsum, sometimes because of impurities and grey, light yellow, light brown and other colors. The stripe is white and transparent. Glass luster, cleavage surface pearl luster, fibrous aggregate silk lustre. Cleavage is very complete and medium, and cleavage pieces are split into 66 and 114 rhombohedral. It's crisp. Hardness 1.5~2. There are slight changes in different directions. The relative density is 2.3.
metallurgy
Architecture
traffic
Packing
Electronics
medicine
printing
hardware
Military
A ship
Space flight
chemical industry