Fluidized roasting reduction kinetics of low-grade pyrolusite coupling with pretreatment of stone coal

Abstract

Based on the fluidized roasting reduction technology of low-grade pyrolusite coupling with pretreatment of stone coal, the manganese reduction efficiency was investigated and technical conditions were optimized. It is found that the optimum manganese reduction efficiency can be up to 98.97% under the conditions that the mass ratio of stone coal to pyrolusite is 3:1, the roasting temperature of stone coal is 1000°C, the roasting temperature of pyrolusite is 800°C, and the roasting time is 2 h. Other low-grade pyrolusite ores in China from Guangxi, Hunan, and Guizhou Provinces were tested and all these minerals responded well, giving ∼99% manganese reduction efficiency. Meanwhile, the reduction kinetic model has been established. It is confirmed that the reduction process is controlled by the interface chemical reaction. The apparent activation energy is 36.397 kJ/mol.

Keywords

pyrolusite / ore roasting / ore reduction / fluidized beds / kinetics / stone coal

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