What is a gypsum powder processing machine?
Gypsum plaster is a binding material consisting mainly of hemihydrate gypsum. It is made by calcium sulfate dihydrate heat treatment at a temperature of 140-180°C.
Dehydration reaction is accompanied by heat absorption. Theoretically, to produce one kilogram of hemihydrate gypsum from calcium sulfate dihydrate, 582 kJ is necessary.
Gypsum plaster production mainly includes crushing, grinding and heat treatment (dehydration). The gypsum rock can be heat treated in the boilers, rotary kilns and other units. The most common method of producing gypsum plaster is processing in gypsum boilers.
Gypsum rock is transported to plant in large chunks. First, it is processed in the jaw, cone or hammer crushers and then ground in mills and simultaneously dried, since it is difficult to grind the gypsum rock containing moisture. Ball mills are most widely used. After having been ground to powder (to the desired fineness) the gypsum rock is fed to a boiler. Dehydration starts at lower temperatures. Crystallization water can be seen evaporating at 60°С.
Boiling duration depends on the size of the boiler, temperature, moisture content and partial dehydration of the gypsum fed. Boiling usually takes from one to three hours. Gypsum 3-4 hours maturing at a temperature of 140-150°C during boiling reduces water demand and increases product strength.
Water demand is greatly reduced when boiling process involves sodium chloride. When in the boiler the gypsum does not contact with flue gases, thus ensuring a clean uniform final product free of fuel ash contamination.
All the units operated at normal pressure and accessing air allow to obtain a final product consisting mainly of fine crystals, which also contains some CaSO4 anhydride and undecomposed raw material particles.
Samara Plant Strommashina offers high-quality gypsum production equipment. In addition to the gypsum production line, the boilers are also equipped with a gypsum plaster production flow diagram involving rotary kilns. The ball mill 1456A (usually of a two-chamber design) is used to grind gypsum rock chunks. But unlike the gypsum boilers, the product calcined in kilns is heterogeneous in terms of modification composition, there is a significant amount of unburnt (calcium sulfate dihydrate) and overburnt (anhydrite) product. In addition to grinding, the ball mill homogeneates product composition through making hemihydrate from unburnt and overburnt product.
Samara Plant Strommashina has prepared a comparative table of gypsum production technologies. This information will be useful to all the professionals who are involved in gypsum industry. We are also ready to provide advisory services and assist in selection of production lines and individual equipment items. Plant Strommashina is a manufacturer of such highly demanded industrial equipment as ball mills, hammer crushers, rotary kilns. Strommashina performs fully integrated works from equipment designing to start-up and subsequent maintenance. Our production capabilities and experience gained by our employees allow us to keep reasonable prices for our equipment.