| abstract |
Pelletized calcium sulfate is prepared from finely divided, natural or synthetic calcium sulfate, wherein the particle size of the finely divided calcium sulfate is at least about 90 per cent by weight less than 200 mu m, there being no particles larger than 500 mu m, and wherein the finely divided calcium sulfate has a free water content of from about 0.5 to about 4 per cent by weight, by pressing the finely divided calcium sulfate in the presence of water with a roll press using a surface pressure of 1 to 5 Mp per cm roller length. |