粉煤灰碱焙烧提高Na_2SiO_3溶液模数试验研究

Study on Increasing Modulus of Sodium Silicate Solution of Fly Ash by Roasting With Caustic Soda

通过加碱焙烧处理,研究了粉煤灰提高碱溶产物Na2SiO3溶液的模数,考察了焙烧温度、碱硅配比、焙烧时间、碱性添加剂用量对Na2SiO3溶液模数的影响。试验结果表明：在300℃、碱硅配比0.5、焙烧时间0.5h条件下用稀碱液浸出,浸出物质硅酸钠溶液的模数在1.1-1.3之间,最高值达1.27,与常温条件下的碱溶法相比,所得硅酸钠溶液的模数显著提高;焙烧过程中,碱中添加碳酸钠降低添加物的碱性不利于硅酸钠的溶出。

Fly ash was treated by roasting with caustic soda then was leached using alkaline solution to obtain high modulus sodium silicate solution. The effects of roasting temperature,time, mass ratio of soda-to-silicon,and using sodium carbonate as additives on the modulus of sodium silicate solution were examined, The results show that the modulus of sodium silicate solution is range of 1.1-1.3 under the conditions of roasting temperature of 300 ℃, mass ratio of soda-to-silicon of 0.5, using dilute alkaline solution to leaching. Compared with alkali dissolution method at normal temperature, the modulus of sodium silicate solution is higher. Adding sodium carbonate in soda has an adverse effect on the leaching of sodium silicate.