Abstract: Corresponding to the ascertained conditions of heat transfer and temperature range of 900~1150℃, self-reduction experiments of carbon composite iron ore hot briquette (CCB) are studied. By analyzing the changes of reduction weightloss and product gases of CCB, self reduction mechanism of CCB is explained. The experimental results show that the self-reduction of CCB in N2 atmosphere meets homogeneous and porous material model. The whole reduction process could be divided into two stages, the reduction rate during the first stage is significantly faster than that during the second one. In the experimental conditions, the reduction of CCB is controlled by the step of gas inner diffusion through the layer of reduction iron product.

Key words: carbon composite iron ore hot briquette, controlling step, self-reduction, reduction kinetic

摘要： 在传热条件一定的前提下，于900~1150℃反应温度范围内进行了热压含碳球团的自还原实验. 通过分析热压含碳球团还原失重和产物气体的变化规律，阐述了热压含碳球团的自还原机理. 结果表明，热压含碳球团的自还原可用多孔物料反应模型进行描述. 整个过程分为两个阶段，第一阶段还原速率明显大于第二阶段. 在本研究条件下，热压含碳球团自还原过程两个阶段的限制性环节均为气体通过还原产物层的内扩散.

关键词: 热压含碳球团, 限制性环节, 自还原, 还原动力学