Research On The Separation Of Iron And Vanadium In Chloride Solution

As a characteristic resource in China, vanadium-bearing titanomagnetite has lots of useful elements such as Fe, Ti and V. The efficient utilization of different elements is of vital importance for the utilization of the resource. The new process was proposed to utilize Fe, Ti and V at the same time by the National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences. However, there are several elements such as Fe and V existing in the leaching solution of vanadium-bearing titanomagnetite. Therefore, the separation of Fe and V is of the key process for the new technology. In this study, D2EHPA was used as an extractant to extract V from the chloride acidic solution with high concentration of Fe (Ⅱ) and low concentration of V (IV). The separation of Fe and V was studied systematically and the main contents are as follows:(1) The extraction of Fe (Ⅲ) using D2EHPA was studied systematically. The extraction of Fe decreased with the decrease of H+concentration, equilibrium time, phase ratio (O/A), D2EHPA concentration, saponification rate, and salt concentration. H2C2O4is a good stripping agent for iron stripping and the optimal stripping conditions were H2C2O4concentration of11wt.%, stripping time of60-80min, stripping phase ratio (O/A) of2:1. The three-stage stripping ratio of iron under the optimal conditions was more than99%.(2) The extraction of V (Ⅳ) from Fe (Ⅱ) bearing chloride acidic solutions was studied systematically. The optimal extraction conditions for V (Ⅳ) were H+concentration of0.4-0.5mol/L, extraction temprature of25-30℃, equilibrium time of60min, saponification rate of50%, phase ratio of1:1, D2EHPA concentration of10%(v/v). The single-stage extraction of vanadium was98%and the extraction of iron was less than10%under the optimal conditions. The optimal stripping conditions for vanadium stripping were H2SO4concentration of20wt.%, stripping time of90min, stripping phase ratio (O/A) of8:1-12:1. The single-stage stripping ratio of vanadium was more than98%and the purity of vanadium product was more than99%(V2O5).(3) The extraction of vanadium from the leaching liquor of vanadium bearing titanomagnetite was studied using orthogonal experiments and the multi-stage countercurrent extraction was used to provide data for industrialization. The four-stage counter current extraction results indicated that the extraction of vanadium was94%and the extraction of impurity elements were less than3.5%under the eatraction conditions of pH of0.99, extraction temperature of30℃, equilibrium time of20min, phase ratio (O/A) of1:3, D2EHPA concentration of20%(v/v). The stripping of vanadium was more than99%under20wt.%H2SO4, stripping phase ratio (O/A) of6:1, stripping time of60min for the two-stage counter current stripping. The stripping of iron was more than98%under11wt.%H2C2O4, phase ratio (O/A) of3:1, stripping time of60min for the two-stage counter current stripping.