The oxidation behavior of MnO2 on the surface of a shale vanadium ore

Abstract

As a typical oxidative leaching aid in the experimental study of vanadium extraction, MnO2 has a strong destructive effect on the lattice of vanadium-containing minerals. Therefore, the effect of manganese dioxide on vanadium leaching was studied by leaching test of shale vanadium ore. Firstly, the phase change, microstructure and possible structure of the compounds during the condition test were studied by EPMA, FT-IR and SEM-EPS. Then the effect of MnO2 on the leaching rate was studied by kinetics. The results show that under the action of manganese dioxide, the leaching control type is changed from chemical reaction control to mixed control type, and the activation energy is greatly reduced. Secondly, the adsorption of shale vanadium ore by manganese dioxide was characterized, and the density of states, the differential charge density under the action of MnO2 and the dissolution behavior of MnO2 on vanadium in minerals during leaching were studied. Based on the simulation results, it is found that there is a molecular orbital interaction between manganese ions and oxygen and hydrogen on the surface of minerals, which will seriously destroy the lattice of vanadium-containing minerals. The strong oxidation of manganese ions will destroy the structure and stability of the whole tetrahedron and accelerate the leaching trend. Under the action of high-valent manganese ions, Al (S7) -O (S1) bond breaks, Al (S7-O) bond breaks, and vanadium is more easily dissociated from minerals. In this paper, the leaching of vanadium from manganese dioxide was studied by the combination of leaching test, kinetics and quantum chemistry. Through the analysis of kinetics, density of states and charge distribution, the leaching process which could not be characterized by the test was analyzed in detail. It also provides a feasible reference for future research.