| 摘要 |
<p>A process for calcined-gypsum production which attains a reduction in the amount of water to be mixed and does not prolong setting time. A raw-materi al gypsum is calcined after a carboxylic acid is incorporated thereinto, whe reby calcined gypsum can be obtained which necessitates a smaller amount of water to be mixed therewith and needs no prolonged setting time. Even when r ecycled gypsum, which leads to an increase in the amount of water to be mixe d, is used in a large amount as a raw material for gypsum, the calcined gyps um produced by the process is reduced in the amount of water to be mixed the rewith and needs no prolonged setting time. Consequently, ordinary gypsum bo ards can be produced without lowering the productivity thereof.</p> |
