界面化学反应控制的萃取动力学研究——新协萃体系D2EHPA-MEHPA萃取Al^(3+)动力学及反应机理

INVESTIGATION ON KINETICS AND MECHANISM OF ALUMINUM EXTRACTION BY A NEW SYNERGISTIC SYSTEM D2EHPA-MEHPA

本文研究了D2EHPA-MEHPA混合萃取剂萃取Al^(3+)的动力学。观察到该体系具有双重协萃放应,既增加Al^(3+)的分配系数,又提高Al^(3+)的萃取速率。从动力学和表面化学的研究结果,证实该混合萃取剂萃取Al^(3+)为界面化学反应控制机制。建立了该混合萃取剂萃取Al^(3+)的反应速率方程式。根据萃合物组成及其红外光谱的研究结果,得到了协萃络合物组成及其生成反应方程式,并讨论了协萃机理。

The extraction and separation of aluminum is known to be an extremely important problem which presents generally in hydrometallurgical solvent extraction process. We take the general problem and renewable resource of a waste Ni-Al catalyzer as background. The extraction kinetics and equilibria of aluminum in the D2EHPA-MEHPA system are studied. It is found that the system has simultaneously two series synergistic effects (kinetic and therm odynamic) . The interfacial chemical reaction can have a predominant effect in determining the extraction. The extraction rate epuation, composition of synergistic complex and synergistic reaction of aluminum with D2EHPA-MEHPA are obtained.