Gypsum Processing Plant & Machinery Solutions

Mined gypsum rock is crushed and screened to a size the mill can take. By-product gypsum from fertiliser or flue gas plants joins the line at this stage instead.

Free moisture is driven off and the rock is ground to a powder before it goes to the calciner. Ground gypsum is lifted to the calciner feed bin.

Heating the ground gypsum drives off part of the chemically combined water and converts it into hemihydrate, the plaster used in building products. Heat is supplied indirectly or by hot gas, depending on the plaster grade being made.

Freshly calcined plaster leaves the calciner hot and reactive, and is cooled and held before use so that its setting behaviour settles down. Cooled plaster goes to storage silos.

Plaster is milled to the fineness the end product needs and classified, with coarse material returned to the mill. Grades of different fineness are stored separately.

Retarders, accelerators and fillers are weighed in and blended so that the plaster sets in the time the application needs. Batches are mixed dry, with no water added at the plant.

Blended plaster is packed into bags, closed and coded, then stacked for despatch. Packing points are vented so that fine plaster is not lost into the packing hall.