METHOD FOR PRODUCING SILICA POWDER HAVING HUGE PARTICLE, HIGH PURITY AND GLOBULAR SHAPE BY ADDING SURFACTANT, VARIOUS CATALYSTS, TETRAETHYLORTHOSILICATE AND ALCOHOL IN WET PROCESS

摘要

PURPOSE: To provide a method for simply producing high purity globular silica powder having huge particle size of about 100 μm in an amount of 5 to 10 tons/day without additional facility cost by adding a mixed solution of surfactant, various catalysts, TEOS(tetraethylorthosilicate) and alcohol in a general wet process. CONSTITUTION: The method for producing silica powder having huge particle, high purity and globular shape comprises a step of preparing a mixed solution by adding TEOS(tetraethylorthosilicate) that is a raw material of silica at an ordinary temperature, alcohol for controlling rates of hydrolysis, polymerization and condensation and distilled water for guiding hydrolysis, polymerization and condensation in a mole ratio of 1:0.4 to 0.6:05 to 4 and adding surfactant for preventing agglomeration of silica particles in a mole ratio of 3.3±1.65% of the distilled water to a mixed solution; a step of guiding the initial stage of hydrolysis by stirring the mixed solution for 15 minutes after adding ammonia to the mixed solution until pH of the mixed solution becomes 10 while holding temperature of the mixed solution to 45 deg.C; a step of inhibiting production of fine silica powder by stirring the mixed solution for 30 minutes while holding temperature of the mixed solution to 0 deg.C after neutralizing the mixed solution by adding hydrochloric acid to the mixed solution until pH of the mixed solution becomes 7; a step of adding acetic acid having a middle acidity to the mixed solution until pH of the mixed solution becomes 4.5 and stirring the mixed solution for 2 to 10 hours, thereby accelerating polymerization and condensation, and uniformly injecting a mixed solution of TEOS and alcohol into the solution during stirring, thereby guiding growth of particles of silica powder at the same time; a step of stopping growth of particles of silica powder by adding ammonia to the mixed solution until pH of the mixed solution becomes 7 and stirring the mixed solution for 10 hours after growing particle size of silica powder to 100 μm; and a step of performing drying and heat treatment on the washed silica powder after sequentially washing the grown silica powder by a filter using distilled water and alcohol.