超细氢氧化铝晶核生长动力学数学模型的建立

Establishment of a kinetic model of alumina trihydrate crystal growth

为了有效控制、调节氢氧化铝制备的工艺参数,创造良好的晶体成核、生长条件,以粉煤灰为原料制备超细氢氧化铝,通过单因素实验分别构建铝酸钠溶液浓度、碳化温度、分散剂掺量、CO2气体浓度、pH值、A试剂加入量、碳化通气速度等影响因素对氢氧化铝粒径影响的回归方程,建立氢氧化铝晶核生长动力学数学模型,然后通过正交实验,确定各因子相关系数.模型检验结果表明,误差在5%以内,具有一定的可信度.采用动力学数学模型可以减少实验工作量,提高工程放大倍数,从而降低研发成本,提高产品产量与质量.

To prepare uhrafine alumina trihydrate from flyash, the establishment of a kinetic model of alumina trihydrate crystal growth has been studied. Through single factor experiment, the regression equations about the concentration of sodium aluminate solution, the carbonation temperature, the dispersant dosage, the con- tent of CO2, the pH value, the A reagent dosage and the veloeity of CO2 gas which influence the particle size have been established respectively. The kinetic model of alumina trihydrate crystal growth was also established, and the correlative coefficients were obtained by the orthogonal experiment. Results of the experiment show that the error is less than 5% and the model is reliable. Through establishing the kinetic model, the technical parameters can be controlled and accommodated effectively, so the best conditions of crystal nucleation and growth can be educed. Adopting this model, the workload can be reduced and the multiples of pilot plant can be enlarged, which can reduce the R＆D cost and improve the ability of competition.