矿粉粒度及反应温度对高磷鲕状赤铁矿制备碳化铁的影响

为探索利用高磷鲕状赤铁矿作为炼钢原料的新途径,在CH4-H2气氛下对高磷鲕状赤铁矿制备碳化铁进行了实验研究,探讨了矿粉粒度对还原和碳化的影响。采用热重法、SEM-EDS和XRD分别对实验中试样还原失重过程、高磷鲕状赤铁矿矿相和碳化产物进行了分析。实验得到120~160目粒度矿粉的反应活化能最低,还原反应活化能为44.95kJ/mol,碳化阶段表观活化能为9.71kJ/mol。从反应速率的角度,利用高磷鲕状赤铁矿制备碳化铁的最佳温度为1 023K,矿粉的最佳粒度为120~160目,总体来讲,温度比矿粉粒度对高磷鲕状赤铁矿制备碳化铁反应速率的影响大。

Effect of hematite particle size and reaction temperature onthe preparation of iron carbide from high phosphorus oolitic hematite

In order to use high phosphorus oolitic hematite as a new raw material for steelmaking, the particle size of high phosphorus oolitic hematite and reaction temperature on the preparation of iron carbide are studied in H2-CH4 atmosphere. The weight loss of sample in reduction process, phase composition of high phosphorus oolitic hematite and carburization products are investigated by means of thermogravimetric method, SEM-EDS and XRD. The SEM-EDS and XRD analysis show that the main compositions of high phosphorus oolitic iron ore are hematite and quartz, and the main microstructure is oolitic clusters with the zonal distribution of hematite and apatite. According to the experiment results, the reaction activation energy of high phosphorus oolitic hematite with size in the range of 120~160 mesh is the lowest. In reduction step, the reaction activation energy is 44.95 kJ/mol, and the apparent reaction activation energy is 9.71 kJ/mol in carburization step. From the perspective of reaction rate, the optimum temperature for preparing iron carbide from high phosphorus oolitic hematite is 1 023 K and the optimum particle size is 120~160 mesh. Generally, compared with iron ore particle size, temperature has much more influence on the iron carbide formation from high phosphorus oolitic hematite.