A PROCESS FOR PRODUCING GYPSUM

摘要

The invention relates to a process for the preparation of a gypsum produc t wherein wherein calcium sulphate hemihydrate and/or calcium sulphate anhyd rite and water are contacted sothatso that the calsiumcalcium sulphate hemih ydrate and/or calcium sulphate anhydrite and the water react with each other and form a gypsum product. The rectionreaction mixture has a dry matter con tent of 34- 84 % by weight in order to obtain a gypsum product which consist s of crystals that are small, flat and of as equal size as possible. The inv ention also realatesrelates to a product prepared by this process. A gypsum product is formed which consists of essentially intact crystals having a siz e of between 0.1 and below 2.0 .mu.m. The products are applicapleapplicable e.g. as fillers or coating pigments in e.g. paper industry.