镁质镍矿高效综合回收关键技术研究

发布时间：2018-04-10 09:35

  本文选题：贫红土镍矿　切入点：焙烧-磁选　出处：《西安建筑科技大学》2017年硕士论文

【摘要】：随着全球对镍需求量的增加以及硫化镍矿的日益枯竭,红土镍矿的开发利用研究工作逐渐成为热点。传统的焙烧-磁选工艺及化学浸出工艺不仅对不同类型红土镍矿适应性较差,还存在着有用组分综合利用率低及产品附加值低等问题。鉴于此,研究以青海某红土镍矿为原料,采用正交试验方法进行了焙烧-磁选及化学浸出工艺对比,并阐明了不同因素对选别效果的影响规律。研究还对酸浸贵液中的镍离子等的综合回收进行了探索试验。在此基础上,取得了以下成果:红土镍矿的焙烧-磁选正交试验结果表明,对焙烧-磁选镍粗精矿的产率和回收率影响的因素显著性依次为磁场强度物料厚度还原时间还原温度还原剂用量。焙烧-磁选镍的优化条件为:还原剂用量为5%、还原温度为800℃、料层厚度为10mm、还原时间为30min、磁场强度为2500A/m。在此条件下可获得产率为22.88%和回收率为38.99%的镍粗精矿。红土镍矿的浸出正交试验结果表明,影响镍浸出率的因素显著性依次为液固比浸出温度硫酸浓度浸出时间搅拌速率,且浸出时间和搅拌速率,浸出时间和浸出温度交互影响均不显著。酸浸红土镍矿的最佳条件为:液固比为4:1,浸出温度为100℃,硫酸浓度为5.2mol/L,浸出时间2.5h,搅拌速率为250r/min,在此条件下镍的浸出率可达98.23%。此外,影响氧化镁浸出率的最显著因素为液固比和浸出温度,浸出时间为一般显著影响因素,而硫酸浓度和搅拌速率为不显著影响因素。氧化镁的浸出优化条件为:液固比为3.5:1,浸出温度为100℃,硫酸浓度为4.3mol/L,浸出时间4h,搅拌速率为250r/min,在此条件下氧化镁的浸出率可达93.92%。浸出贵液中不同离子的综合回收试验结果表明,分批加入117g氢氧化钠,反应时间为25min,控制矿浆pH值在5~6范围内,可获得镍铁混合沉淀产品。该产品在1320℃的条件下煅烧2h,经磁选后可获得镍的品位为1.69%,回收率为82.04%。滤液经静置析晶及硫化除镍净化处理后,在温度为150℃,搅拌速率为350 r/min,硫酸镁与氢氧化钠的摩尔比为1:2.5,硫酸镁质量浓度为3.5%,晶种添加量为硫酸镁的3%,反应时间为3h的条件下,采用水热合成法可以获得结晶良好的碱式硫酸镁晶须。研究既可为红土镍矿的工业化生产提供理论依据,也对同类矿石的现场生产有一定的指导意义。
[Abstract]:With the increase of global demand for nickel and the depletion of nickel sulphide ore, the development and utilization of laterite nickel ore has gradually become a hot spot.The traditional roasting magnetic separation process and chemical leaching process not only have poor adaptability to different types of laterite nickel ores but also have some problems such as low comprehensive utilization ratio of useful components and low added value of products.In view of this, the roasting, magnetic separation and chemical leaching processes of a laterite nickel ore in Qinghai Province were studied by orthogonal test, and the influence of different factors on the separation effect was clarified.The comprehensive recovery of nickel ions from acid leachate was also studied.On this basis, the following results have been obtained: the roasting and magnetic separation orthogonal test results of laterite nickel ore show that,The factors that influence the yield and recovery of roasting magnetic separation nickel concentrate are in turn the reduction time of reduction time of magnetic field strength material thickness and the amount of reducing temperature reductant.The optimum conditions for roasting and magnetic separation of nickel are as follows: reducing agent dosage is 5, reduction temperature is 800 鈩，

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