异戊醇从氯化物-磷酸体系中萃取盐酸的动力学

Kinetics of hydrochloric acid extraction from chloride-phosphoric acid system by isoamyl alcohol

采用上升液滴法研究异戊醇萃取盐酸的动力学,考察二相接触面积、水相中初始盐酸、磷酸浓度对盐酸萃取速率的影响,以比较磷酸和盐酸的萃取行为。实验结果表明,盐酸的初始正向萃取速率与二相界面积无关,随水相初始盐酸、磷酸浓度的增大而增大,异戊醇萃取盐酸可能属相内反应控制模式。水相中盐酸的存在促进磷酸的萃取,用较高浓度的工业盐酸分解开阳磷矿有利于湿法磷酸的分离和净化。经非线性最小二乘法回归实验数据,得出25℃时异戊醇萃取盐酸的动力学方程,其决定性指标为0.993 9,速率常数的相对标准偏差为7.69%。

The extraction kinetics of hydrochloric acid with isoamyl alcohol was investigated by using the rising drop technique. The effects of interracial area between two phases, the initial concentrations of HCl and H3PO4 in aqueous phase on the extraction rate of HCl were studied to compare the extraction behaviors of the two acids. The experimental results show that the initial forward extraction rate of HCl increases with the increasing of the initial concentrations of both acids in aqueous phase, and the interfacial area between two phases almost has no effect on the extraction rate of HCl. Hydrochloric acid extracted by isoamyl alcohol might be a chemical reaction regime. The existence of HCl in aqueous phase promotes to extract H3PO4, so it is beneficial to separate and purify the wet process H3PO4 produced by decomposition of Kaiyang phosphate rock with higher concentration of industrial HCl. The extraction kinetics equation of HCl at 25 ℃ regressed from experimental data with nonlinear least square method can be expressed, its decisive index is 0. 993 9, and the relative standard deviation of rate constant is 7.69%.