氯化物—磷酸体系中异戊醇萃取磷酸的动力学研究

Study on Extraction Kinetics of Phosphoric Acid in the System Chloride-Phosphoric Acid by Isoamyl Alcohol

采用上升液滴法研究了氯化物—磷酸体系中异戊醇萃取磷酸的动力学,考察了两相接触面积和水相中磷酸、盐酸初始浓度对磷酸萃取速率的影响。结果表明:磷酸的初始正向萃取速率随着两相界面积和水相磷酸、盐酸初始浓度的增大而增大,异戊醇萃取磷酸可能属扩散控制模式,磷酸的初始正向萃取速率与水相中磷酸浓度呈准二级反应,与盐酸浓度呈一级反应。经线性最小二乘法回归实验数据,得出25℃时异戊醇萃取磷酸的动力学方程为Rp=4.719×10-8c1p.802c1Cl.004,其速率常数的计算值与实验值的相对标准偏差为5.02%。

The extraction kinetics of phosphoric acid in the system chloride-phosphoric acid by isoamyl alcohol was investigated using the rising drop technique. The effects of interfacial area, the initial concentrations of H3PO4 and HCl in aqueous phase on the extraction rate of H3PO4 were studied. The experimental results showed that the initial forward extraction rate of H3PO4 was found to increase with the interfacial area between the two phases and the initial concentrations of H3PO4 and HCl in aqueous phase, and extracting H3PO4 by isoamyl alcohol might be a diffusion controlling regime. The initial forward extraction rate as a function of H3PO4 concentration was quasi two orders and as a function of HCl concentration was first order. The extraction kinetics equation of H3PO4 at 25℃ was regressed from experimental data with linear least square method could be expressed as Rp =4. 719 × 10^-8cp^1.802cCl^1.004 , and the relative standard deviation of computed values from experimental data of rate constant was 5.02%.