PURPOSE: To reinforce the growth of crystals by treating the surface of a porous metal support with acid, afterwards, impregnating it in a synthetic gel and crystallizing a zeo-type material on the support.
CONSTITUTION: The porous metal support of the stainless steel or the like having an average pore diameter of 0.1 to 200 μm is impregnated in an organic solvent, degreased, afterwards, impregnated in an aquous solution having the concentration of acid such as hydrochloric acid of 0.01 to 5 mol over a period of 1 to 24 hours, next washed and dried. Besides, an NaAlO2 aqueous solution is added to an Na2SiO3 aqueous solution, mixed and crystallized and a hydrogel forming the crystalline zeo-type material is adjusted. Next, the cleaned porous metal support is impregnated in the adjusted hydrogel and left while heating and after the zeo-type material is crystallized on the support, the support is taken out, sufficiently washed and dried. Afterwards, the process for impregnation in the hydrogel, crystallization, following washing and drying is repeated again more than twice and a filter coated with the crystal membrane of the zeo-type material having prescribed thickness is provided.
GURAHAMU JIYON BURATSUTON
CHIMOSHII DO BIRIAAZU NEIRAA
JIEREMII DEIBITSUDO TOMUKINSUN