| 摘要 |
The invention relates to a gypsum product which consists of essentially intact crystals having a size of between 0.1 and below 2.0μm. The product is especially suitable as a coating pigment or filler in paper manufacture. The invention also relates to a process for the preparation of a gypsum product, wherein calcium sulphate hemihydrate and/or calcium sulphate anhydrite, water and a crystallization habit modifier are contacted so that the calcium sulphate hemihydrate and/or calcium sulphate anhydrite and the water are reacted with each other and form a crystalline gypsum product. The calcium sulphate hemihydrate and/or calcium sulphate anhydrite is/are used in such an amount that the reaction mixture formed from the calcium sulphate hemihydrate and/or calcium sulphate anhydrite, the water and the crystallization habit modifier has a dry matter content of between 50 and 84 % by weight. Then, said gypsum product can be formed which consists of essentially intact crystals having a size of between 0.1 and below 2.0μm. |
