(1. 太原理工大學(xué) 化學(xué)化工學(xué)院，太原 030024；
2. 太原理工大學(xué) 省部共建煤基能源清潔高效利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，太原 030024；
3. 山西省民用潔凈燃料工程研究中心，太原 030024；
4. 太原科瑞康潔凈能源有限公司，太原 030006)
摘 要: 以氫氣(H2)和甲烷(CH4)等為還原劑的氣基冶煉，對(duì)于解決傳統(tǒng)冶金行業(yè)所面臨的“雙碳”問(wèn)題意義重大。以紅土鎳礦為研究對(duì)象，在不同還原溫度、還原時(shí)間、氣體濃度等條件下，探討了CH4與紅土鎳礦中鐵鎳氧化物的還原行為。并結(jié)合XRD、SEM-EDS、氣相色譜等表征手段，對(duì)紅土鎳礦及其焙燒產(chǎn)物物相和形貌等進(jìn)行了深入分析。結(jié)果表明：當(dāng)還原溫度為900 ℃、還原時(shí)間為60 min、CH4濃度為50%時(shí)，可獲得鎳品位為3.06%、回收率為52.09%的精礦。精礦中鎳品位和回收率較低的原因主要是由于NiO的還原不徹底，即尾礦中仍有大量的鎳存于硅酸鹽中；以及部分還原后的鎳鐵合金晶粒過(guò)細(xì)，易流失于尾礦與濾液中。CH4與紅土鎳礦的還原過(guò)程是在低溫下緩慢進(jìn)行；在高溫(900 ℃)時(shí)部分CH4裂解產(chǎn)生H2和炭黑，而主要的還原反應(yīng)是在CH4和H2的協(xié)同作用下進(jìn)行。
關(guān)鍵字: 紅土鎳礦；甲烷；還原行為；鐵鎳合金；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
