Roasting reduction and its kinetics of low-grade pyrolusite by biomass char

Abstract

Abstract: ABSTRACT Contrast experiments of low-grade pyrolusite reduction roasting were performed with biomass char and activated carbon as the reductant in a tube furnance, founding that biomass char is obviously better in terms of roasting time and manganese reduction efficiency in the tube furnance. The manganese reduction efficiency of pyrolusite using a reductant of biomass char replacing fossil fuel was studied as a function of roasting temperature, roasting time and the dosage of biomass char. X-ray diffraction analysis was carried out on the roasting products, and the results indicate that pyrolusite roasting reduction experiences the process of MnO2→Mn2O3→Mn3O4→MnO.The results show that under the conditions of roasting temperature 800℃, roasting time 50 min, the dosage of biomass char 10% of the quality of ore sample, manganese reduction efficiency greater than 98% for MnO2 in pyrolusite can be achieved. Based on the results, the reduction kinetics was also investigated, and it is confirmed that the reduction process is controlled by interface chemical reaction. The apparent activation energy of the reduction is about 43.896 kJ·mol-1.

Key words: low-grwde pyrolusite, biomass char, reduction roasting, mechanism study, reaction kinetics

References

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