Method for preparing sodium stannate by calcinating high-silicon cassiterite concentrate soda

The invention discloses a method for preparing sodium stannate by calcinating high-silicon cassiterite concentrate soda. The method has the advantages that reactions among stannic oxide, silicon dioxide and sodium carbonate in a soda calcination process are regulated through control of calcination conditions such as the sodium carbonate ratio, the calcination temperature and the atmosphere in a two-stage calcination process, formation of sodium-silicon-tin ternary oxides is inhibited, and generation of the sodium stannate is promoted, so that the conversion rate of the sodium stannate is increased, and the recovery rate of tin is increased to more than 98.6%. 本发明公开了一种利用高硅锡石精矿苏打焙烧制备锡酸钠的方法，通过控制两段焙烧过程碳酸钠配比、焙烧温度、气氛等焙烧条件，调控苏打焙烧过程中二氧化锡、二氧化硅和碳酸钠之间的反应，抑制钠硅锡三元氧化物的形成，同时促进锡酸钠的生成，最终提高锡酸钠的转化率，将锡回收率提高至98.6％以上。