铝酸钾溶液碳酸化分解的动力学

Kinetics of carbonation decomposition of potassium aluminate solution

对铝酸钾溶液碳酸化分解过程进行研究,建立碳酸化分解过程的动力学模型。借鉴拜耳法晶种分解的动力学模型,对碳分动力学数据进行多元回归,得到动力学方程。结果表明:碳酸化分解的表观活化能为39.2708kJ/mol,说明铝酸钾溶液碳酸化分解需要突破的壁垒小;瞬时晶种量对碳酸化分解过程的影响较小;相比铝酸钠溶液碳酸化分解,苛碱浓度对铝酸钾溶液分解的影响更大。铝酸钾溶液在40~80℃碳化分解,所得氢氧化铝为拜耳石型。

The kinetics of carbonation decomposition of potassium aluminate solution was investigated and the kinetic model was established. Referencing seeded precipitation model, the kinetic equation was deduced through multiple linear regression according to experimental data. The equation shows that the apparent activation energy is 39.2708 kJ/mol, demonstrating that the carbonation decomposition reaction of potassium aluminate solution is easier than that of sodium aluminate solution. The instantaneous seed quantity has a small effect on the process of carbonation decomposition; the alkali concentration has more significant impact on the carbonation decomposition of potassium aluminate solution than that of sodium aluminate solution. XRD analysis demonstrates that the obtained products at 40-80 ℃ belong to Gibbsite Al（OH）3.