A PROCESS FOR PRODUCING SILICA, SODIUM SULFITE AND SODIUM HYDROGEN SULFITE WITH SODIUM SULFATE

摘要

: The present invention provides a process for producing silica, sodium sulfite and sodium hydrogen sulfite with sodium sulfate, wherein quartz sand, sodium sulfate and carbon are mixed and charged into a furnace for reaction and the obtained solid sodium silicate and sulfur dioxide are used to prepare silica, sodium sulfite and sodium hydrogen sulfite according to the following steps: 1) To produce silica: said solid sodium silicate is dissolved in water and filtered to produce a water glass solution; then sulfuric acid is reacted with said water glass solution to produce precipitated silica and sodium sulfate; and the precipitated silica is washed, filtered, liquefied and dried to produce silica; 2) To produce sodium sulfite: soda is added into a sodium hydrogen sulfite solution to produce sodium sulfite solution; one part of said sodium sulfite solution is concentrated and evaporated to obtain dry sodium sulfite; and the other part of the sodium sulfite solution is reacted with the sulfur dioxide produced during the production of the sodium silicate to produce sodium hydrogen sulfite solution, which can be recycled and reused in step (2); 3) To produce sodium hydrogen sulfite: soda is added into a sodium hydrogen sulfite solution followed by reacting with the sulfur dioxide produced during the production of the sodium silicate to produce a supersaturated sodium hydrogen sulfite solution, which is crystallized and dried to obtain a dry solid sodium hydrogen sulfite. The process of the present invention produces various products at low production cost and without causing environmental problems, and thus it has great practical value. No. of Pages : 7 No. of Claims : 4