Abstract
In this paper, electric field as a chemical process intensification methods was utilized in the leaching experiment of manganese from pyrolusite using pyrite as reductant. The key leaching parameters under the action of electric field, such as liquid-to-solid ratio, mass ratio of pyrolusite and pyrite, H2SO4 molar concentration, stirring speed, leaching temperature, direct current density, were investigated, respectively. The results suggest the optimum parameters of liquid-to-solid ratio, mass ratio of pyrolusite and pyrite, H2SO4 molar concentration, stirring speed, leaching temperature, direct current density were 10ml/g, 10:3, 1.6mol/L, 250 r/min, 353K, 700 A/m2 under the leaching time of 3h, the manganese extraction efficiency of 96.22% was obtained, the manganese extraction rate of leaching with electric field is nearly 36% higher than that of leaching without electric field, indicating that the electric field enhanced ion migration to improve manganese leaching rate. In addition, phase analysis and morphology detection revealed that leaching slag with electric field contains less elemental sulfur and unreacted pyrolusite as well as pyrite. This further showed that the introduction of electric field promoted the high valence conversion of elemental sulfur, decreased the encapsulation effect of elemental sulfur on minerals, and led to efficient leaching of manganese.