赤铁粉矿在H_2气氛中的闪速还原行为

Flash reduction behavior of hematite ore fine in a hydrogen atmosphere

通过高温下的动力学实验对铁粉矿在H_2气氛中的闪速还原行为进行了研究.采用XRD、SEM和金相显微镜对反应后铁粉矿的物相组成和单个粉矿颗粒表面及内部微观形貌的演变规律进行了分析,采用化学分析法获得了反应后赤铁粉矿的还原度.结果表明:铁粉矿高温下发生的闪速还原仍然遵循Fe_2O_3→Fe_3O_4→FeO→Fe的逐级还原规律.粉矿颗粒的剖面由未反应核和产物层构成,符合未反应核模型的描述.采用模型函数配合法得出铁粉矿与H_2在高温下发生闪速还原反应的限制性环节是界面化学反应,进一步基于动力学模型计算得到,闪速还原的表观活化能为311 kJ/mol.

The flash reduction behavior of hematite ore fines in a hydrogen atmosphere was investigated with the high temperature experiments.The phase composition of the hematite ore and the morphology of individual partially reduced iron ore particles was analyzed by XRD,SEM and optical microscope.The reduction degree was obtained by chemical titration method.It was found that the evolution of iron oxides during the flash reduction process follows the reduction order of Fe 2O 3→Fe 3O 4→FeO→Fe.The polished section of the partially reduction iron ore particle is consisted of an unreacted shrinking core and a product layer,which can be depicted with the unreacted shrinking core model.According to the model fitting method,the rate controlling step during the flash smelting reduction process is the interfacial chemical reaction.The apparent activation energy is 311 kJ/mol.