Abstract: Particulate, porous, water-insoluble amorphous poly(silicic acid) which is characterized by an average pore diameter of at least 100 A and a surface area of 500 to 850 m.sup.2 /g, by an average pore diameter of 50 A to about 300 A and a surface area of greater than 850 m.sup.2 /g, or by a pore volume of 1.5 ml/g to about 8.5 ml/g and a surface area of greater than 850 m.sup.2 /g; process for preparing particulate, porous, water-insoluble, amorphous poly(silicic acid) by acidifying an appropriate aqueous silicate solution, allowing the silicic acid thus formed to polymerize to poly(silicic acid), freezing the acidified solution, and thereafter thawing the acidified solution and isolating therefrom, washing, drying and recovering particulate poly(silicic acid), said process further characterized in that:(a) the amount of silicate in the aqueous silicate solution is such that the SiO.sub.

Abstract: In a process for preparing particulate, porous, water-insoluble amorphous poly(alumino-silicate) having a Si/Al gram-atomic ratio of about 1:1 to 10:1, a pore volume of greater than 0.5 ml/g, an average pore diameter of 50 to 200 A and a surface area of 200 to 600 m.sup.2 /g by mixing an aqueous solution of an appropriate aluminate and an aqueous solution of an appropriate silicate, allowing the aluminate and silicate in the resultant mixture to polymerize to poly(alumino-silicate), freezing the mixture and thereafter isolating, washing, drying and recovering particulate poly(alumino-silicate) therefrom, said process characterized in that:(a) the amounts, respectively, of aluminate and silicate, calculated as Al.sub.2 O.sub.3 and SiO.sub.