摘要 |
A process for preparing shaped articles from waste gypsum from wet-process phosphoric acid production comprises: (1) mixing wet calcium sulfate hemihydrate with 0.5-20% by wt. of calcium hydroxide or calcium oxide, (2) adjusting the total water content of said mixture to 20-40% by wt., if necessary, and (3) molding shaped articles from said mixture by compression molding. The shaped objects so prepared have a low density and relatively high compressive strength. |