铝酸钠溶液碳酸化分解过程动力学

对铝酸钠溶液碳酸化分解过程的动力学进行了研究.在对碳酸化分解过程中的氢氧化钠被二氧化碳中和以及氢氧化铝析出两个过程进行比较后,认为整个碳酸化分解过程是受氢氧化铝析出过程控制,仍然遵循种分机理.借鉴种分过程动力学模型,给出了动力学方程.方程表明:碳酸化分解反应的表观活化能为75.115 KJ/mol,这与晶种分解过程的活化能大致相当,也与碳酸化分解过程仍然遵循晶种分解机理的观点相吻合;碳酸化分解过程强烈地受到过饱和度的影响.

Kinetics of carbonation decomposition of sodium aluminate solution

The kinetics of carbonation decomposition of sodium aluminate solution was investigated. Based on the camparison between the two essential processes in carbonation decomposition-one is the reaction between sodium hydroxide and carbon dioxide, the other is the process of aluminum trihydroxide precipitation, it is revealed that the latter is the controlling step. With the seeded precipitation model in the literature, the model of kinetics of carbonation decomposition and its corresponding kinetic equation were deduced. The results show that the apparent activation energy of carbonation is 75.115 kJ/mol, which serves as a well indication of the similarity on mechanism between the process of carbonation and that of seeded precipitation process. The effect of seed on carbonation precipitation can be well explained only when the concept of instantaneous seed is employed to the kinetic equation. The process of carbonation precipitation is intensively affected by super-saturation.