(1. 重庆大学 材料科学与工程学院，重庆 400044；
2. 昆明理工大学 省部共建复杂有色金属资源清洁利用国家重点实验室，昆明 650093)
摘 要: 采用热分析动力学方法，研究了Na2CO3作用下硅镁质型红土镍矿非等温碳热还原的动力学规律，确定了主要的动力学参数，查明了还原过程的物相变化。结果表明：添加Na2CO3可降低碳热还原开始温度约250 ℃，并加速碳的气化反应；碳热还原过程可分为三个阶段，即初始阶段(α=0~0.15)、中期阶段(α=0.15~0.60)和衰变阶段(α=0.60~1.0)。初始阶段的活化能随着还原反应的进行由223 kJ/mol快速下降到76 kJ/mol，受二维扩散控制；中期阶段活化能先增加后降低，该阶段受化学反应控制；衰变阶段主要发生FeO及Fe2SiO4的还原反应，活化能由184 kJ/mol缓慢减小到132 kJ/mol，随后又增加到173 kJ/mol，该阶段受化学反应控制。与无添加剂相比，添加Na2CO3后极大地促进了红土镍矿的碳热还原，降低了整个过程的活化能。
关键字: 红土镍矿；动力学；非等温；碳热还原；碳酸钠
（1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:Kinetics study of non-isothermal carbothermic reduction of nickel laterite ore was carried out in the presence of Na2CO3. Based on the thermogravimetry and kinetic analysis methods, relevant kinetic parameters were determined and the phase transformation during reduction was revealed. The results indicate that the starting temperature of carbothermic reduction is reduced and the gasification of carbon is intensified after adding Na2CO3. The reduction process can be divided into three stages: the initial stage (α=0-0.15), the middle stage (α=0.15-0.60) and the decaying stage (α=0.60-1.0). The activation energy of initial stage decreases from 223 kJ/mol to 76 kJ/mol in which the two-dimensional diffusion is identified as the mechanism function. For the middle stage, the activation energy firstly increases and then decreases. The chemical reaction mechanism is found to be the best fit. The decaying stage also belongs to chemical reaction mechanism, while the activation energy of this stage decreases from 184 kJ/mol to 132 kJ/mol and then increases to 173 kJ/mol. The reductions of Fe and Fe2SiO4 are the main reactions in this stage. Compared to the reduction in the absence additive, the reduction process is enhanced and the corresponding activation energy can be reduced after adding Na2CO3.
Key words: nickel laterite ore; kinetics; non-isothermal; carbothermic reduction; Na2CO3
