REMOVAL OF SILICATES DISSOLVED FROM SOLVENTS DIRECTLY SYNTHESIZED FROM ALCOHOL AND SILICON

摘要

PROBLEM TO BE SOLVED: To remove a dissolved silicon compound and other contaminants and restore a used solvent so as to be reusable by bringing the used solvent containing the dissolved silicon compound into contact with a carboxylic acid and carrying out an acid decomposing reaction. SOLUTION: (A) A used solvent containing a dissolved silicon compound is brought into contact with (B) a carboxylic acid (preferably acetic acid or formic acid) in an amount sufficient to carry out a reaction for converting the dissolved silicon compound into solid silicates and/or silica and the solvent which is the component A is then separated from the converted component B to thereby restore the solvent. The solid suspended in the solvent is preferably separated before the contact step. The component B is preferably added to the component A in 0.5-6 ratio of the carboxylic acid equivalents/silicon atoms. The concentration of the component B is preferably at least 10 wt.%.