China Petroleum & Chemical Corporation
Preparation of molecular sieve and treatment of silicon-containing wastewater therefrom

Abstract:

A method for the treatment of silicon-containing wastewater from the preparation of a molecular sieve or a catalyst includes the step of contacting the silicon-containing wastewater with at least one acid or at least one alkali, so that at least a part of the silicon elements in the silicon-containing wastewater form a colloid. A mixture containing a colloid is thus obtained. A silicon-containing solid phase and a first liquid phase are produced by a solid-liquid separation. A solid phase and a second liquid phase are produced by a solid-liquid separation after at least a part of the metal elements in the first liquid phase form a precipitate. At least a part of the second liquid phase is subjected to electrodialysis to produce an acid liquor and/or an alkali liquor. The silicon-containing solid phase can be used as the raw material for a molecular sieve synthesis.