白云鄂博铁精矿内配碳球团还原动力学研究
赵文广1，高强1，赵卫东2，王永斌1,彭 军1,安胜利1
（1.内蒙古科技大学材料与冶金学院，包头 014010
2.包钢薄板坯连铸连轧厂，包头014010)
关健词:白云鄂博铁精矿；含碳球团；还原动力学; 活化能
中图分类号：TF554文献标志码：A
摘要:为降低CO2排放量，发展以H2为还原剂的炼铁生产方式势在必行。针对富氢气固还原工艺中存在着气体利用率低和还原供热不足等问题，利用热重法研究了温度、碳氧比、煤粉粒度对白云鄂博铁精矿含碳球团还原速度的影响。结果表明，在碳氧摩尔比为1.1时，还原温度越高, 煤粉越小，含碳球团还原速度越大。基于碳气化反应、气相扩散和界面反应的含碳球团还原速度方程能较好地处理本研究的数据。在850℃下，由未反应核模型得出气体内扩散活化能和界面反应活化能分别为87.3kJ/mol和306kJ/mol,还原温度越高，扩散阻力越大，化学反应阻力越小。在950℃下，还原反应过程速度由气体内扩散控制。
Researchon the Reduction kinetics of Baiyunobo Iron Concentrate of Carbon-ContainingPellets
Zhao Wen-guang1, Zhao Wei-dong2, WangYong-bin1, Peng Jun1, An Sheng-li1
(1.Materialsand Metallurgy School , Inner Mongolia University of Science and Technology, Baotou,014010, China, 2.Compact Strip Production Plant, Baotou Iron and Steel (Group)Co.,Baotou 014010,China)
Key words: Baiyun obo ore；carbon-containing pellets；reduction kinetics;activation energy
Abstract:Hydrogen-enriched reduction in blast furnace is an innovativetechnology responding to the requests for further reduction of CO2 emissionand sustainable development on a global scale. Based on the fact that the hydrogen-enriched gas-solid reductionprocess is low at the utilization rate of gas with insufficient supply of heat ,theeffect of temperature，carbon-oxygen ratio andcoal fines size on the reduction rate ofBaiyun obo iron concentrate of carbon-containing pellets was studied by using thermogravimetricanalysis (TG) method. Theresult indicated that while carbon-oxygen ratio was 1.1, the reduction rate increased with increasingthe temperature and decreasing the size of the coal fines. Four well-known kinetic equations canwell represent most of the experimental data, thus allowing an accurateevaluation of the rate constants. The gas internal diffusion activity energyand interfacial reaction activity energy calculated with unreacted core model is87.3kJ/mol and 306kJ/molrespectively. The greater is the reduction temperature, the higher is the internaldiffusion resistance and the smaller is the chemical resistance. It was henceconcluded that gas internal diffusion should be the rate controlling step for thereduction of carbon-containing pellets at 950℃.