METHOD FOR PREPARING PRECIPITATED SILICA FROM SODIUM METABISULFITE OR SODIUM SULFITE

摘要

A method for preparing precipitated silica includes the reaction of sodium metabisulfite or sodium sulfite with sand, wherein a) sand is mixed with sodium metabisulfite or sodium sulfite; b) the mixture thus obtained is melted to produce solid sodium silicate and sulfurous anhydride; c) the solid sodium silicate is dissolved in water to provide a sodium silicate aqueous solution, d) the sulfurous anhydride is reacted with the sodium silicate aqueous solution to provide a mixture containing precipitated silica; and e) the precipitated silica is separated from said mixture.