METHOD AND APPARATUS FOR PRODUCTION OF GLOBULAR SILICAGEL

摘要

A method comprises (i) reacting water glass (18 wt.% SiO2) with 6-12N H2SO4 (or mixt. soln. of H2SO4 and Al2(SO4)3) to form stable silica hydrosol (pH 1.5-3.5, and not gelling for 24hr), (ii) supplying these sol and dil.-water glass (3-10 wt.% SiO2) by 2:1-7:1 ratio into a mixing nozzle, (iii) spraying to org. solvent phase (upward circulated with const. rate, maintained at 60-100 deg.C, and not mixing with these) through nozzles for gelation while maintaining globular shape, and (iv) underwater-transporting the gelled product to the outside of gelation tower to dry and separate.