Gypsum To Plaster Of Paris
Process of preparing plaster of pairs from Gypsum
Plaster of pairs is obtained from the calcination of Gypsum. In preparation of Plaster, proper selection of Gypsum, its preparation and classification is very important. Thereafter, several process to available to calcine gypsum into Plaster of Paris. The two most preferred techniques are:
The involved chemical reaction is as follows:
(CaSO4, 2 H2O) + heat = (CaSO4,ÃÂÃ¢ÂÂÃÂÃÂ½ H2O) + 1.5 H2O
However, in either of the process, controlling certain critical calcination parameters is very important to yield quality plaster crystals. The size and shape of clusters determines the performance of the plaster. There after the crystal of plasters are ground, using different grinding process; here the main motive is to obtain uniform sized particles of the product. Finally, the plaster powder is mixed with additives and fillers, which adds the rheological characteristics like setting times, fluidity, hardening kinetics, permeability, mechanical strengths, resistance to abrasion, etc.