Patent ID: 8986642
Filing Date: 2015-03-24
Classification: B01J,C01B,C01P,C08F,Y10T

Abstract:
1. A process for producing spherical beads comprising at least one metal oxide and/or semimetal oxide, having a mean diameter in the range from 10 to 120 μm, a BET surface area in the range from 400 to 800 m 2 /g and a pore volume in the range from 0.3 to 3.0 cm 3 /g, wherein the diameter of a given bead at any one point of said bead deviates by less than 10% from the average diameter of said bead and the surface of said bead is substantially smooth, said process comprising the steps: (A) providing a mixture comprising at least one at least partially water-miscible organic solvent, water and at least one precursor compound of the at least one metal and/or semimetal oxide as mixture A, (B) providing a mixture comprising at least one at least partially water-miscible organic solvent, water and at least one acid as mixture B, (C) combining the mixtures A and B and reacting the at least one precursor compound of the at least one metal and/or semimetal oxide with said at least one acid to obtain a mixture C comprising an aqueous phase comprising the spherical beads and an organic phase, (D) separating the organic phase from the mixture C obtained in step C to obtain an aqueous phase comprising the spherical beads, (E) optionally treating the spherical beads obtained in step (D) with at least one acid, and (F) drying the spherical beads obtained in step (D) or (E), wherein the at least one precursor compound of the at least one metal oxide and/or semimetal oxide is selected from the group consisting of alkali metal silicates, alkaline earth metal silicates, colloidal silica sols, and mixtures thereof.