Study of Gypsum Dehydration Time in CaCl2 Solution

The preparation of the alpha form of calcium sulphate hemihydrate is technically relatively complicated. The idea is to allow 1.5 molecules of water contained in gypsum to leave through dehydration in liquid form. This can only be achieved under hydrothermal conditions, namely in an autoclave or by increasing the boiling point of the solution in which the gypsum is located during dehydration. The paper deals with the dehydration of gypsum in a calcium chloride solution. The influence of the concentration and temperature of the selected solution on the dehydration time of the gypsum was monitored.