Prodn. of shaped zeolite aluminosilicate bodies - from a mixt. of calcined clay precursor bodies and aq. alkali soln. contg. aluminosilicate seed

摘要

Coherent composite zeolite bodies comprising a mixt. of crystalline aluminosilicate zeolite dispersed in an amorphous alumina-silica porous residue of anhydrous calcined kaolin, are made by: mixing calcined kaolin clay precursor bodies with aq. alkali, and heating to convert the calcined kaolin clay to zeolite dispersed in alumina-silica, the heating being carried out in the presence of amorphous aluminosilicate nucleation centres. The mixt. may be aged prior to heating. Used in a wide range of catalytic and adsorptive processes. Presence of nucleation centres during heating densitises the growth of crystalline zeolite to variations in the source of clay used to form the bodies and to variations in the calcination conditions used to produce the bodies. Prods. also have good strength and attrition resistance.