METHOD FOR PURIFYING SILICA

摘要

PURPOSE: Provided is a method for purifying silica which can effectively and perfectly remove impurities of iron oxides contained in silica, thereby causing an increase of purification yield. CONSTITUTION: The method comprises steps of (S1) supplying a silica ore by a conveyer belt, (S2) pulverizing the silica ore to form a first group having a first size of 30 mm or less using a first pulverizer; (S3) further pulverizing the silica powder pulverized in the step(S2) to form a second group having a second size of 10 mm or less using a second pulverizer; (S4) mixing the pulverized silica powder prepared in the step(S3) with ball mills having at least two diameters in a weight ratio of 2.5 to 3.5:4.5 to 5.5 in a grinder rotating about 27 to 30 per 1 minute to form silica powder having a size of 60 to 150 mesh; (S5) selecting the ground silica powders according to their sizes and returning the silica powders having a size exceeding 60 mesh to the grinder; (S6) removing the ground silica powders having a size of less than 150 mesh and supplying the silica powders having a size of 60 to 150 mesh to a first tank; (S7) washing the silica powders having a size of 60 to 150 mesh by ultrasonic; (S8) transferring the washed silica powders to a second tank to settle down sludge with impurities; and (S9) hydrating and drying the silica powders.