(1. 太原理工大学 化学化工学院，太原 030024；
2. 太原理工大学 省部共建煤基能源清洁高效利用国家重点实验室，太原 030024；
3. 山西省民用洁净燃料工程研究中心，太原 030024；
4. 太原科瑞康洁净能源有限公司，太原 030006)
摘 要: 以氢气(H2)和甲烷(CH4)等为还原剂的气基冶炼，对于解决传统冶金行业所面临的“双碳”问题意义重大。以红土镍矿为研究对象，在不同还原温度、还原时间、气体浓度等条件下，探讨了CH4与红土镍矿中铁镍氧化物的还原行为。并结合XRD、SEM-EDS、气相色谱等表征手段，对红土镍矿及其焙烧产物物相和形貌等进行了深入分析。结果表明：当还原温度为900 ℃、还原时间为60 min、CH4浓度为50%时，可获得镍品位为3.06%、回收率为52.09%的精矿。精矿中镍品位和回收率较低的原因主要是由于NiO的还原不彻底，即尾矿中仍有大量的镍存于硅酸盐中；以及部分还原后的镍铁合金晶粒过细，易流失于尾矿与滤液中。CH4与红土镍矿的还原过程是在低温下缓慢进行；在高温(900 ℃)时部分CH4裂解产生H2和炭黑，而主要的还原反应是在CH4和H2的协同作用下进行。
关键字: 红土镍矿；甲烷；还原行为；铁镍合金；晶粒
（1. College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
2. Key Laboratory for Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China;
3. Shanxi Engineering Center of Civil Clean Fuel, Taiyuan University of Technology, Taiyuan 030024, China;
4. Taiyuan Green Coke Energy Co., Ltd., Taiyuan 030006, China）
Abstract:The gas-based smelting mainly based on H2 and CH4 is of great significance for solving the "Dual carbon" problem faced by the traditional metallurgical industry. In this paper, the laterite nickel ore is the research object, under the conditions of different reduction temperature, reduction time and gas concentration, the reduction behavior of CH4 with iron-nickel oxide in laterite nickel ore was discussed. Combined with XRD, SEM-EDS, gas chromatography and other characterization methods, the phases and morphologies of laterite nickel ore and its calcined products were analyzed in depth. The results show that, under the conditions of reduction temperature of 900 ℃, reduction time of 60 min and CH4 concentration of 50%, the grade of nickel concentrate obtained is 3.06% and the recovery rate is 52.09%. The reasons for the low grade and recovery rate of nickel concentrate are as following: the reduction of NiO is not complete, there is still a large amount of nickel in the silicate of the tailings. A part of the reduced nickel-iron alloy is too fine, so it is lost easily in the tailings and filtrate. The reduction process of CH4 is slow at low temperature, and a part of CH4 cracks at high temperature (900 ℃) to produce H2 and carbon black. The main reduction reaction is carried out under the synergistic effect of CH4 and H2.
Key words: laterite nickel ore; methane; reduction behavior; iron-nickel alloy; crystal size
