Abstract: Pre-reduction of fine iron ore at low temperatures was studied with single factor and orthogonal experiments. The effects of ratio of gas to solid, reaction time, temperature of furnace, particle size and kind of reducing agent on the reduction degree of fine iron ore were examined respectively. The process parameters were optimized and the behavior of carbon deposition was also discussed. The experimental result showed that the particle size of 14~20 mm, temperature of furnace in the range 660~700℃, reaction time between 180~220 s, and kind of reducing agent CO 0~20%(j) were the optimal conditions, and the maximal reduction degree of 70.16% was achieved. In addition, the XRD and chemical analysis of reduction product indicated that the carbon deposition occurred during the reduction process. The presence of hydrogen could accelerate the carbon deposition rate.

Key words: fine iron ore, reduction at low temperature, H2-CO mixing gas, carbon deposition

摘要： 研究了铁矿微粉低温输送预还原中气固比、还原时间、炉温、矿粉粒径、还原剂种类等参数对矿粉还原率的影响，并运用正交设计和模式识别方法对工艺参数进行了优化，对预还原过程中样品的附碳行为进行了探讨. 结果表明，在矿粉粒径14~20 mm、炉温660~700℃、反应时间180~220 s、还原气成分CO 0~20%(j)的优化条件下，预还原率较高，最高达70.16%. XRD分析表明，还原样品发生碳吸附现象，少量氢气可提高碳吸附率.

关键词: 铁矿微粉, 低温还原, H2-CO混合气体, 附碳