【摘要】：隨著硫化鎳資源的逐步枯竭,低品位鎳紅土礦的綜合利用日益受到人們的關(guān)注。本文針對云南鎂質(zhì)貧鎳紅土礦工藝礦物學(xué)特性,惰性氣氛中不同溫度下焙燒后礦相轉(zhuǎn)變進行了系統(tǒng)研究。并在熱力學(xué)理論分析的基礎(chǔ)上,初步研究了該礦的煤基還原-磁選工藝。為我國云南大批量呆滯鎂質(zhì)貧鎳紅土礦礦的短流程、低成本清潔利用提供理論支撐。工藝礦物學(xué)研究結(jié)果表明,原礦主要礦物為蛇紋石和鐵礦物,其中蛇紋石占87%,鐵礦物占10%,另有少量的綠泥石、石英、高嶺石、蒙脫石等。鎳含量為0.82%,鎳的物相分析表明,鎳主要以類質(zhì)同象的形式分布在利蛇紋石礦物中,分配率為80.5%,其余的鎳以氧化鎳、硫化鎳、吸附性鎳以及以類質(zhì)同象取代氧化鐵礦中鐵的形式存在。本文借助X射線衍射儀(XRD)、熱重-差熱分析儀(TG-DSC)、傅里葉變換紅外光譜儀(FT-IR)、掃描電鏡(SEM)和比表面積測定儀(BET)等,對N2氛圍中鎂質(zhì)貧鎳紅土礦在不同溫度下(400-1300℃)焙燒后的樣品的礦相轉(zhuǎn)變進行了系統(tǒng)研究。該礦經(jīng)400℃焙燒后,礦相無明顯變化。610℃焙燒后,發(fā)生脫羥基作用,蛇紋石(利蛇紋石和纖蛇紋石)轉(zhuǎn)變?yōu)榉蔷B(tài)物質(zhì),樣品中出現(xiàn)許多裂縫。800℃焙燒后非晶態(tài)物質(zhì)重新結(jié)晶生成新的鎂硅酸鹽(鎂橄欖石和頑輝石),比表面積明顯減少。對鎳紅土礦煤基還原-磁選工藝進行研究,通過理論計算和實驗研究,分析了還原溫度、還原時間、還原劑配比等對鎳鐵成分及金屬回收率的影響。研究結(jié)果表明：還原溫度對生成物物相變化影響最大,當(dāng)焙燒溫度為1250℃,恒溫時間60 min,還原劑用量為8%時,鎳鐵富集效果最好。最優(yōu)條件下,得到鎳鐵精礦中鎳、鐵品位分別為2.56%和60.55%,鎳、鐵回收率分別為15.18%和30.45%。
[Abstract]:With the gradual depletion of nickel sulphide resources, the comprehensive utilization of low grade nickel laterite ore has attracted more and more attention. In this paper, the mineralogical characteristics of magnesia-poor nickel laterite ore in Yunnan Province and the phase transition after calcination at different temperatures in inert atmosphere have been systematically studied. On the basis of thermodynamic theory analysis, the coal-based reduction-magnetic separation process of the mine is studied preliminarily. It provides theoretical support for the short process and low cost clean utilization of large quantities of stagnant magnesia-poor nickel-laterite ore deposits in Yunnan. The results of technological mineralogy show that the main minerals of the ore are serpentine and iron, of which 87 are serpentine, 10 are iron minerals, and a few are chlorite, quartz, kaolinite and montmorillonite. The nickel content was 0.82%. The phase analysis of nickel showed that nickel was mainly distributed in serpentine minerals in the form of similar substance, and the distribution rate was 80.5%. The remaining nickel was nickel oxide, nickel sulphide, nickel sulfide, nickel oxide, nickel sulfide, Adsorptive nickel and the form of iron in oxidized iron ore are substituted for isomorphism. In this paper, (XRD), thermogravimetric differential thermal analyzer (TG-DSC), Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM) and specific surface area analyzer (BET) were used. The phase transition of magnesia-poor nickel-poor laterite samples calcined at different temperatures (400-1 300 鈩，

本文編號：2265538