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1、 西安建筑科技大学硕士学位论文 红土镍矿直接还原焙烧-磁选试验研究 专 业：钢铁冶金 研 究 生：贺 峰 指导教师：杨双平 教授 摘 要 随着高品位、易开采的硫化镍矿日益枯竭和国内不锈钢产业的快速发展，低品位红土镍矿的利用受到越来越多的关注。本课题以国内某进口的褐铁矿型红土镍矿为原料，对红土镍矿进行还原焙烧磁选试验研究。研究的主要内容包括原料的矿物组成、化学成分、还原焙烧、磁选分离以及镍铁精矿的矿物组成和化学成分分析，并得到了以下结论： （1）红土镍矿的还原焙烧试验的正交试验可以得出焙烧温度、还原剂用量、反应时间、原料粒度，对镍回收率影响的主次顺序为：焙烧温度还原剂用量反应时间原矿粒度。焙烧温
2、度对试验的结果影响最大，焙烧温度越高，镍的品位和回收率就越大。但是实际生产表明，在 1200的时候，红土镍矿在回转窑内出现了严重的结圈现象，阻碍了正常生产。因此本试验选择最佳的还原焙烧温度为1150。 （2）红土镍矿的还原焙烧过程添加剂的试验表明：红土镍矿无添加剂作用下进行直接还原磁选效果不理想，适宜的添加剂可以强化红土镍矿的还原、分离的效果。含 S 添加剂在还原焙烧过程中可以降低镍铁晶粒的熔点和表面张力，促进镍铁晶粒的聚集、长大，磁选分离效果明显。复合添加剂要比单一的添加剂对镍的还原、富集效果更明显，配加 5%的复合添加剂 T-5，镍的品位由原来的没有添加剂的 3.0%提高到 4.1%。 （
3、3）通过还原焙烧磁选试验，得到最优的试验条件为：原料粒度-200 目，焙烧温度 1150，还原剂为褐煤，还原剂的粒度为-60 目，还原剂的用量为 4%，复合添加剂 T-5 为焙烧添加剂,添加剂用量为 5%，焙烧时间 90min，焙烧后焙砂的粒度-300 目，磁场强度为在 3000GS 扫选再 1000GS 精选。在最佳试验条件下，镍的品位为 4.1%，铁的品位为 80%，镍、铁的回收率分别为 92%和 77%。镍铁精矿的矿物组成表明，镍并不是以镍单质的形式存在，而是以镍铁合金的形式存在于镍铁精矿中。镍铁精矿中镍品位高，为后续冶炼减少渣量、节能能耗，是电炉冶西安建筑科技大学硕士学位论文 炼不锈钢
4、的理想原料。 本课题的研究结果表明：采用还原焙烧磁选工艺可以选择性的富集镍和铁，为后续镍铁的冶炼减少了渣量，降低了能耗，这对红土镍矿的开发和利用有重要的意义。 关键词：红土镍矿；还原焙烧；磁选分离；添加剂；镍铁 西安建筑科技大学硕士学位论文 Research on Direct Reduction Roasting and Magnetic Separation of Laterite Nickel Ore Specialty: Ferrous Metallurgy Graduate: He Feng Adviser: Professor Yang Shuangping Abstract Wi
5、th the high grade and the easy mining nickel sulfide ores being used up, and the rapid development of Chinas stainless steel industry, more and more attention has been put on the use of the low grade nickel laterite. This paper, taking one kind of imported limonite type laterite ore as raw material,
6、 researched on the direct reduction roasting and magnetic separation. The experimental study mainly include the mineral composition, chemical component, reduction roasting, magnetic separation, as well as the analysis of mineral composition and chemical component of nickel-iron concentrate. The conc
7、lusions are given as follows: (1)The primary and secondary order of the effection to nickel recovery can be provided as: calcinations temperature reductant dosage reaction time raw material particle size by the orthogonal test of reductive roasting nickel laterite. The test results show that paramet
8、er of calcinations temperatures have great influence on the grade and recovery of nickel. The higher calcinations temperature is, the more grade and recovery of nickel are. However, the actual production show that the laterite nickel ore has a serious phenomenon of ring formation in rotary kiln when
9、 the temperature is 1200, which hinder the normal production seriously. Therefore, the test take 1150 as the best reduction temperature. (2)Additives in reduction roasting nickel laterite process show that: the effect of reduction roasting-magnetic is not good without additives. However the effect c
10、an be strengthened within suitable additives. The additives containing sulphur can reduce the melting point and surface tension of the nickel-iron crystals in the roasting reduction process, and promote the aggregation, growth of the nickel-iron crystals, which has 西安建筑科技大学硕士学位论文 obvious effcet. The
11、 compound additives has more effect than single additives. The nickel grade increase from 3.0% without additives to 4.1% within the 5% of compound additive T-5. (3)The optimal test conditions of reduction roasting-magnetic are that: the particle size of ore being -200mesh, roasting temperature 1150,
12、 lignite as reductant, the particle size of reduction being -60mesh, the 4% of reductor dosage, the roasting additives being compound additives T-5, the 4% of T-5 dosage, reduction time being 90min, roasting product particle size of -300mm, roughing in 3000GS and then choiceness in 1000GS of magneti
13、c-field intensity. Under the optimal conditions, nickel grade was 4.1%, and iron grade was 80%. The recovery of nickel and iron were 92% and 77%. XRD analysis of nickel-iron concentrate show that nickel dose not exist as a nickel single substance, but rather exists as the form of a nickel-iron alloy
14、. The nickel-iron concentrate with high grade nickel can reduce the amount of slag and save the energy consumption, which is the ideal raw material for making stainless steel. The result of this paper shows that: the reduction roasting-magnetic separation process can enrich nickel and iron selective
15、ly, and reduce the amount of slag for subsequent smelting of ferronickel. The energy consumption also shrunk at the same time. it is great significance for the development and utilization of the nickel laterite. Keywords: laterite ore, reduction roasting, magnetic separation, additive, ferronickel西安建筑科技大学硕士学位论文 I 目 录 1 文献综述 . 1 1.1 引言 .1 1.2 镍及其主要化合物的物理化学性质 .1 1.2.1 镍的主要物理化学性质 .1 1.2.2 镍的主要化合物及性质 .
