生物质焦焙烧还原低品位软锰矿及其动力学

采用生物质焦和活性炭粉作还原剂,在管式炉中进行了低品位软锰矿焙烧还原对比试验.分别研究了焙烧温度、焙烧时间、生物质焦用量等条件对软锰矿还原率的影响,对焙烧产物进行了X射线衍射分析.结果表明,生物质焦在焙烧时间和还原效率上优于活性炭粉;软锰矿焙烧还原依次经历Mn O2→Mn2O3→Mn3O4→Mn O过程;在焙烧温度为800℃,焙烧时间为50 min,生物质焦用量为10%时,软锰矿还原率可达98%以上,在此基础上导出了还原动力学方程,并证实还原过程由界面化学反应控制,表观活化能为43.896 k J·mol-1.

Roasting Reduction and Its Kinetics of Low-Grade Pyrolusite by Biomass Char

Roasting reduction contrast experiments of low-grade pyrolusite were performed by using biomass char and activated carbon as the reductant in a tube furnace. The effects of roasting temperature， roasting time and the dosage of biomass char on manganese reduction efficiency of pyrolusite were studied， and X-ray diffraction analysis was carried out for the roasting products. The results indicated that biomass char is obviously better than activated carbon in roasting time and manganese reduction efficiency.Roasting reduction of pyrolusite undergoes the process of MnO2→Mn2O3→Mn3O4→MnO. Manganese reduction efficiency greater than 98% was achieved when roasting temperature is 800℃， roasting time is 50min and the dosage of biomass char is 10%. Based on the results， the reduction kinetics equation was derived， and it is confirmed that the reduction process is controlled by interface chemical reaction， and the apparent activation energy is about 43.896kJ·mol-1.