| 摘要 |
A process for preparing a synthetic substantially crystalline sodium aluminosilicate of the zeolite A type is disclosed. The process comprises rapidly and simultaneously introducing a sodium silicate and a sodium aluminate solution under thorough agitation at a constant by volume ratio which provides for a reaction mixture the content of which is equivalent to a molar ratio of x' Na2O/ 1 Al2O3/ y SiO2/z' H2O wherein x' is from about 6.5 to about 9.0, y is from about 1.7 to about 2.2 and z' is from about 180 to about 250, maintaining the reaction mixture at a temperature of from about 70 DEG to about 100 DEG C. under stirring for a sufficient period of time, usually 1-3 hours, in order to allow the initially amorphous reaction product to crystallize and recovering the substantially crystalline product from the resulting suspension. The essential feature of the process is a continuously maintained constant molar ratio Na2O/ Al2O/ SiO2/H2O throughout the reaction mixture during the entire course of the process. The resulting product exhibits a small particle size, an excellent wettability and a high calcium binding power, and is especially suited as a detergent additive. |
