| 摘要 |
1,129,008. Retarded cement. W. R. GRACE & CO. 29 Sept., 1966 [22 Oct., 1965], No. 43548/66. Heading C1H. Cement contains 0À1 to 5À0% FeSO 4 as a retarder, and no Ca(OH) 2 or compound convertible by hydrolysis into Ca(OH) 2 . The FeSO 4 can be added to the clinker or at any subsequent stage. The retarded cement can form a mortar with sand. |
