It is one of the most widely used building materials. It is used for plasters and increasingly in panels. Natural gypsum is sodium sulphate with two water molecules. For its industrial use, it is calcined in controlled circumstances removing this water to give anhydrite and hemidrates. The material coming from gas desulfurization is also widely used. It has a smaller particle size and contains less impurities of abrasive minerals as well as of not wished compounds. The percentages of these sulphates make the gypsum behave in a way or another depending on the setting velocity and mechanical resistances.
ANIVI can supply the following equipment for the different types of gypsums:
> Roller Mills using hot gas, when short burning times are required which make quick gypsums for panels or blocks fabrication.
> Indirect Kilns, when slower and high mechanical resistance gypsums are required, such as in mortars for walls.
> Direct Rotary Kilns, which produce quicker gypsums than with the Indirect Kilns and although they do not admit very fine feeds, they involve a more economical system.
Furthermore, it is possible to use Roller Mills for the reduction of the particle size to the Kilns before and after calcination.