PRODUCTION OF HIGH-PURITY KAOLINITE-LIKE MINERAL

摘要

PURPOSE:To obtain a high-purity kaolinite-like mineral containing neither impurities nor unreacted substances in production by hydrothermal synthesis by blending an aqueous solution of sodium silicate with an aqueous solution of aluminum sulfate at a specific pH, subjecting Na ion to ion exchange for proton to give a gel and using the gel as a raw material. CONSTITUTION:An aqueous solution of sodium silicate is uniformly blended with an aqueous solution of aluminum sulfate while maintaining at pH 4-12 to give a mixed gel of silica and alumina. Then, Na in the gel is subjected to ion exchange for proton by using a cationic exchanging ion exchange resin containing a sulfonic group or carboxylic group as a functional group. Then, the prepared raw material gel is fed to an autoclave so as to give 5wt.% slurry concentration, subjected to hydrothermal treatment at 220 deg.C for 10 days, cooled, washed with water, filtered and dried to give a kaolinite-like mineral, a reaction product.