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通过等温热重实验分析CO/CO2/N2气氛中硼铁精矿还原和无烟煤气化的动力学特性,求得Fe3O4→Fe O和Fe O→Fe两个还原阶段及碳素溶损反应的活化能分别为74.72,65.74与194.72 k J/mol.建立了硼铁精矿含碳球团还原过程数学模型,并通过实验验证了模型的准确性.考察了球团尺寸、孔隙率、反应活化能对金属化率的影响,结果表明,球团尺寸从φ16 mm×8 mm增加至φ32 mm×16 mm,前期还原速率降低,但最终金属化率从85%上升至99.4%;球团孔隙率对还原过程影响较小;碳素溶损反应活化能上升抑制还原进行,但对最终金属化率没有影响,而当界面还原活化能从初始值的0.95倍上升至1.05倍时,不仅反应速率下降,最终金属化率也从99.59%降低至94.81%.从活化能对还原过程影响推断,反应前期还原过程受碳气化和铁氧化物还原联合控制,后期为铁氧化物还原反应控制.
The isothermal thermogravimetric experiment was used to analyze the kinetic characteristics of the reduction of boron iron concentrates and anthracite gasification in the CO / CO2 / N2 atmosphere. The kinetic characteristics of the iron reduction reaction and the redox reaction of Fe3O4 → Fe O and Fe O → Fe were obtained The activation energies were 74.72, 65.74 and 194.72 kJ / mol, respectively. The mathematical model of the reduction process of boron-bearing iron ore concentrate containing carbon was established and the accuracy of the model was verified by experiments.The pellet size, porosity, The results showed that the size of the pellets increased from φ16 mm × 8 mm to φ32 mm × 16 mm, the reduction rate decreased in the early stage, but the final metallization rate increased from 85% to 99.4%. The pellet porosity Which has little effect on the reduction process. The activation energy of carbon loss reaction increases to restrain the reduction, but it has no effect on the final metallization rate. When the interface reduction activation energy increases from 0.95 times to 1.05 times the initial value, not only does the reaction rate decrease , And the final metallization rate also decreased from 99.59% to 94.81% .Inferred from the influence of activation energy on the reduction process, the reduction process in the early stage of the reaction was controlled by carbon gasification and iron oxide reduction and later was controlled by the iron oxide reduction reaction.