含硅铝酸钠溶液深度脱硅动力学及脱硅机理的研究

Study on the Kinetics and Mechanism of Deep Desilication of the Sodium Aluminate Solution Containing Silicon Dioxide

对含硅铝酸钠溶液添加氧化钙-硫酸钙复合脱硅剂深度脱硅进行了研究。实验表明：脱硅后溶液中SiO2的含量受脱硅时间和脱硅温度的影响很大，随着脱硅温度升高和脱硅时间的增长，SiO2的含量逐渐减小。并由SiO2的含量与脱硅时间和脱硅温度的关系，推导出了该脱硅过程中的动力学方程：-dC／dt=42．95exp（-2．10×10^4／RT）×C^1.04，在313—371K，脱硅速度随反应温度提高而加快，此过程的表观活化能为2．10×10^4J／mol。通过渣相的X衍射测试分析，探讨了氧化钙-硫酸钙复合体系的脱硅机理。

An experimental research on advanced desilication of the sodium aluminate solution containing silicon dioxide by means of adding CaO - CaSO4 compound desiliconizing agent has been performed. The experimental resuits showed that the content of SiO2 in desiliconized solution is greatly influenced by the desilication time and desilication temperature. The content of SiO2 is minished with the rising of desilication temperature and the prolonging of desilication time. By means of the relations between SiO2 content and desilication time and desilication temperature,the kinetic equation is inferred as follows; -dC/dt =42.95exp（ -2.1×10^4/RT） x C^1.04. The rate of the desilication process is increased with increasing of the temperature in the range of 313 - 371 k. It was concluded that the apparent activation energy of desilication process was 2.10×10^4J/tool. The desilication mechanism of sodium aluminate solution containing silicon dioxide by using CaO -CaSO4 compound desiliconizing agent was examined.