Extraction kinetics of separating molybdenum(Ⅵ) over iron(Ⅲ) from high acid leach solutions with mixtures of P507 and N235

Abstract

In view of the difficulty of separating molybdenumVI over ironIII from high acid leach solutions, the extraction kinetics of separating molybdenumVI/ironIII with mixtures of 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) and long chain tertiary amine (N235) was investigated using a Lewis cell to enhance the separation efficiency. Parameters affecting the extraction process such as stirring speed, specific interfacial area, and temperature were studied. The results show that the extraction process of MoVI takes place in the bulk aqueous phase, and the extraction rate is controlled by diffusion (The apparent activation energy was calculated to be 16.66 kJ/mol). The rate constants (kf) of mean MoVI extraction was calculated as 100.3, and the extraction rate equation was established: - d[Mo]/dt = 100.3[Mo](a)[P507](o)0.35[N235](o)0.24. The extraction reaction of MoVI had a fast rate in the studied range of solution conditions, but FeIII was not extracted. Moreover, the separation mechanism was speculated by two-phase titration, Fourier transform infrared spectroscopy and Nuclearmagneticresonancespectroscopy.