Effect of MgO on Oxidation of Vanadium Slag at High Temperature

Based on two considerations of making full use of the residual heat of V-slag and exploring a novel green V extraction process, this paper employs MgO as the roasting additive, blows oxygen into the molten V-slag, and uses the residual heat of the V-slag for pre-roasting at high temperature. The influence of MgO on the phase structure of V-slags during oxidation has been investigated by XRD and SEM/EDS. The result shows that MgO as the roasting additive can convert V-slag at a high temperature of 1723 K. With the increase of blowing time of oxygen, the trivalent V in the spinel phase gradually disperses in the silicate matrix and then concentrates in the form of magnesium vanadate solid solution (Mg, Mn, Ca)(2) V2O7. Furthermore, with the increase of MgO content, the peak intensity of the Mg2V2O7 diffraction peak increases significantly. When the MgO content in V-slag increases from 4.01 to 12.74 wt%, the extraction efficiency increases from 18.99 to 64.07%.

Automated summary

By adding MgO and blowing oxygen into the molten V-slag, the residual heat of V-slag can be effectively utilized to increase the extraction efficiency of vanadium.