(北京科技大學(xué) 土木與環(huán)境工程學(xué)院，北京 100083)
摘 要: 紅土鎳礦所含的蛇紋石礦物在焙燒過程中會出現(xiàn)脫羥基和重結(jié)晶等相變。選取兩種不同試樣進(jìn)行直接還原焙燒-磁選實驗，研究蛇紋石的高溫相變對直接還原焙燒紅土鎳礦的影響。對兩種紅土鎳礦進(jìn)行熱重分析、XRD衍射分析和掃描電鏡分析，研究兩種紅土鎳礦中的蛇紋石礦物在焙燒過程中相變過程的異同及其對直接還原的影響。結(jié)果表明：兩種試樣所含主要礦物為蛇紋石和針鐵礦，其熱重分析曲線相似；在焙燒過程中，試樣2在較低溫度下出現(xiàn)橄欖石相。在最終的焙燒礦物相中，與試樣1相比，試樣2中出現(xiàn)石英相；與試樣2相比，試樣1的蛇紋石顆粒內(nèi)部在焙燒后形成較多裂隙。因此，試樣2的鎳回收率較低。
關(guān)鍵字: 紅土鎳礦；蛇紋石；直接還原；相變
（School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The phase transitions of dehydroxylation and recrystallization will happen in the roasting process of serpentine mineral in the laterite nickel ore. To study the effect of phase transition of serpentine on the direct reduction of laterite nickel ore, the direct reduction roasting-magnetic separation test was conducted on two samples. The similarities and differences of phase change of the two kinds of laterite nickel ore in the process of roasting and the influence on direct reduction roasting were analyzed by TGA, XRD and SEM. The results show that two kinds of samples contain the same main minerals of serpentine and goethite, and the TGA curves are similar. Olivine phase appears earlier in Sample 2 at low temperature in the roasting process. The quartz phase appears in the final roasting mineral phases of Sample 2 but not in that of Sample 1. Compared with Sample 2, there are more fracture in serpentine particles of Sample 1 after roasting. Therefore, the nickel recovery rate of Sample 2 is lower.
Key words: laterite nickel ore; serpentine; direct reduction; phase transition
