Method for producing sodium silicate and coarse pore spherical silica gel from sulfuric acid slag

The invention discloses a method for producing sodium silicate and coarse pore spherical silica gel from sulfuric acid slag. The method comprises repeatedly washing primarily discharged waste slag of sulfuric acid slag treatment through a hydrochloric acid solution with a concentration of 9-16% for 21-32min, washing the filter cake through clear water three times, carrying out filtration to obtain pure filter cake, mixing the pure filter cake and liquid sodium hydroxide according to a pure mass ratio of 1: 1.08-1.58, carrying out a reaction process on the mixture in a pressure reactor subjected to steam heating to obtain a sodium silicate solution, filtering the sodium silicate solution, carrying out light concentration and cooling on the sodium silicate solution to obtain a sodium silicate solution product, diluting the sodium silicate solution through water, mixing the dilute sodium silicate solution and dilute sulphuric acid, carrying out gelatinization balling, carrying out aging for 6h, carrying out wash