ULTRA PURE HIGH CRYSTALLINITY SILICAS

摘要

This invention relates to an improved process for producing ultra-pure high crystallinity porous silicas by dealuminating a crystalline aluminosilicate, optionally in the presence of a silicon compound, and calcining the dealuminated product at a high temperature. The dealumination step may be carried out by steam treatment of the aluminosilicate. Unlike conventional processes the present invention does not rely on low alumina aluminosilicates produced from relatively expensive raw materials such as tetraalkyl ammonium hydroxides.