Process for producing white carbon black and sodium sulphite by sodium sulfate method

A method is provided to produce silica and sodium sulfite with sodium sulfate, wherein a mixture of quartz sand, sodium sulfate and carbon is reacted to produce solid sodium silicate and sulfur dioxide; said solid sodium silicate is dissolved in water and then filtered to obtain a sodium silicate solution; said sodium silicate solution is brought into contact with the sulfur dioxide to produce precipitated silica and sodium sulfite solution; the resultant mixture is filtered; the filter cake is acidified and then goes through filtration, washing and drying to obtain silica; and the filtrate is concentrated and dried to get sodium sulfite. The process of the present invention has great value due to its simple steps, low production cost and reduction of environmental problems.