熟料溶出二次反应过程中Al_2O_3损失动力学机理

为了分析熟料溶出过程的二次反应机理,对该过程中Al2O3损失动力学进行了详细的研究.采用DY8型低压群釜进行熟料溶出实验,分别用EDTA容量法和硅钼蓝比色法分析溶液中Al2O3和SiO2的质量浓度.根据给出的动力学方程,得到铝酸钠溶液中Al2O3、Na2CO3和NaOH质量浓度对该反应的级数分别为0.94、0.03和0.14.该结果表明,导致SiO2进入铝酸钠溶液和由此带来的Al2O3损失主要是熟料中硅酸钙与NaAl(OH)4相互作用的结果,而NaOH和Na2CO3的贡献则相对较小.在此结论的指导下进行了熟料高浓度溶出实验,实验结果表明,合理地调控影响因素可使熟料高浓度溶出过程二次反应得到有效控制.

Kinetic mechanism of Al2O3 loss in secondary reaction during clinker leaching

In order to analyze the mechanism of secondary reaction during clinker leaching, the kinetics of Al₂O₃ loss in this process was investigated. The clinker leaching experiment was conducted in the DY8 gang kettle. The Al₂O₃and SiO₂ concentration in the sodium aluminate solution was measured by the EDTA volumetric method and silicon molybdenum blue photo colorimetric method respectively. According to the obtained kinetic equation, the orders of the reaction with respect to the Al₂O₃, Na₂CO₃ and NaOH concentration in the sodium aluminate solution are estimated to be 0.94, 0.03 and 0.14. It can be thought that the interaction between calcium silicate in clinker and NaAl（OH）₄ is the main reason to result in the entrance of SiO₂ into sodium aluminate solution and the loss of Al₂O₃. Thus, the high concentration clinker leaching experiment was performed. The experimental results indicate that the secondary reaction during high concentration clinker leaching can be effectively controlled when the major influencing factors are properly adjusted and controlled.