Cement foaming agent, also known as foaming concrete foaming agent, refers to an admixture that can reduce the surface tension of liquid and generate a large amount of uniform and stable foam for the production of foamed concrete. Foaming agent is a kind of substance that can make its aqueous...
Calcium Sulfate Boiling Point
Calcium sulfate is an inorganic compound with the formula CaSO4. It occurs naturally as the mineral gypsum and in a number of hydrates. One form, known as plaster of Paris, is used for building and as a desiccant. The other, gypsum, is used in the production of construction materials such as stucco, division panels, ceiling tablets and wall plaster. Calcium sulfate can also be produced as a byproduct of other reactions or by synthetic processes. It is soluble in water but insoluble in alcohol and other solvents.
At low temperatures, gypsum, or calcium sulfate dihydrate, CaSO4 * 2H2O, is the stable form of calcium sulfate; it is insoluble at high temperature. Gypsum can be dehydrated to produce anhydrous calcium sulfate by heating it. This reaction is known as the calcination of gypsum.
Figure 7 shows the polymorphism of CaSO4. The b-form calcium sulfate hemihydrate, CaSO4
Besides its use as a raw material in the manufacture of building products, gypsum is also widely used in the paper industry. As a filler, it makes paper thicker and brighter so that it is easier to write and draw on. It is also used as a retardant in the drying process of paints and coatings. Another useful application is in the refining of zinc where it is used to co-precipitate heavy metals such as barium from solution of zinc sulfate.