| 摘要 |
<p>A crystalline type-A zeolite powder, which can be used as a phosphate substitute in detergents, is produced by precipitation reaction in that in a defined sequence sodium-tetrasilicate solution and sodium-aluminate liquor are simultaneously passed to a reactor containing water, whereupon sodium-tetrasilicate solution is added first and sodium-aluminate liquor thereafter. The crystalline product has an average particle size of 6.7 to 8 .mu.m and a narrow particle size distribution curve.</p> |
