云南镁质贫镍红土矿矿物学特性及其煤基还原—磁选工艺研究

发布时间：2018-10-12 08:57

【摘要】：随着硫化镍资源的逐步枯竭,低品位镍红土矿的综合利用日益受到人们的关注。本文针对云南镁质贫镍红土矿工艺矿物学特性,惰性气氛中不同温度下焙烧后矿相转变进行了系统研究。并在热力学理论分析的基础上,初步研究了该矿的煤基还原-磁选工艺。为我国云南大批量呆滞镁质贫镍红土矿矿的短流程、低成本清洁利用提供理论支撑。工艺矿物学研究结果表明,原矿主要矿物为蛇纹石和铁矿物,其中蛇纹石占87%,铁矿物占10%,另有少量的绿泥石、石英、高岭石、蒙脱石等。镍含量为0.82%,镍的物相分析表明,镍主要以类质同象的形式分布在利蛇纹石矿物中,分配率为80.5%,其余的镍以氧化镍、硫化镍、吸附性镍以及以类质同象取代氧化铁矿中铁的形式存在。本文借助X射线衍射仪(XRD)、热重-差热分析仪(TG-DSC)、傅里叶变换红外光谱仪(FT-IR)、扫描电镜(SEM)和比表面积测定仪(BET)等,对N2氛围中镁质贫镍红土矿在不同温度下(400-1300℃)焙烧后的样品的矿相转变进行了系统研究。该矿经400℃焙烧后,矿相无明显变化。610℃焙烧后,发生脱羟基作用,蛇纹石(利蛇纹石和纤蛇纹石)转变为非晶态物质,样品中出现许多裂缝。800℃焙烧后非晶态物质重新结晶生成新的镁硅酸盐(镁橄榄石和顽辉石),比表面积明显减少。对镍红土矿煤基还原-磁选工艺进行研究,通过理论计算和实验研究,分析了还原温度、还原时间、还原剂配比等对镍铁成分及金属回收率的影响。研究结果表明：还原温度对生成物物相变化影响最大,当焙烧温度为1250℃,恒温时间60 min,还原剂用量为8%时,镍铁富集效果最好。最优条件下,得到镍铁精矿中镍、铁品位分别为2.56%和60.55%,镍、铁回收率分别为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，

本文编号：2265538