铅锌硫化矿尾矿生物浸出工艺优化研究

发布时间：2018-04-04 09:09

本文选题：铅锌硫化矿尾矿　切入点：嗜酸性化能无机营养型微生物　出处：《广东工业大学》2015年硕士论文

【摘要】：选矿过程产生大量尾矿废渣,尾矿蕴含着大量有价金属,是一种可利用的再生资源。金属硫化矿尾矿含硫量较高,硫可以作为嗜酸性化能无机营养型微生物生长的营养源,从而为实现硫化矿尾矿的生物浸出提供了可能。铅锌硫化矿尾矿的生物浸出,不仅能回收尾矿中的铅和锌,实现资源的综合利用,而且可以减少矿尾中重金属的释放对水环境和土壤的污染,具有重要经济和环境意义。论文的研究内容包括：嗜酸性化能无机营养型微生物的筛选；铅锌硫化矿尾矿成分分析；浸出条件对硫化矿尾矿中铅、锌浸出率的影响；单矿物(方铅矿和闪锌矿)的生物浸出规律。首先,从某硫化铅锌矿尾矿库的尾矿库坑水中筛选出嗜酸性化能无机营养型微生物,通过测定Fe2+氧化为Fe3+的转化率,评价微生物的氧化活性。生物浸出的尾矿样品取自某硫化铅锌矿尾矿库,对矿样成分分析表明,硫、铁含量很高,主要以S2-和Fe2+形态存在,为嗜酸性化能无机营养型微生物提供了生存条件。然后,评估了不同的酸(HCl、H2SO4和HNO3)对尾矿生物中铅、锌浸出率的影响,结果表明不同的酸对Pb浸出效果由高到低为HClHNl3H2SO4,对Zn浸出效果由高到低为H2SO4HClHNO3,这可能与酸根阴离子与Pb2+和Zn2+生成的化合物浓度积大小及对尾矿生物生长影响有关。其次,考察了采用HCI作为添加酸的情况下,矿浆固液质量比、矿浆初始pH值、不同微生物接种量对硫化铅锌矿尾矿中铅、锌浸出率的影响。结果表明：固液比越大,Pb的浸出率峰值越大,峰值出现的时间越晚；固液比越大,Zn的浸出率峰值越小,峰值出现的时间越晚；初始pH值越小,Pb的浸出率峰值越大。当矿浆初始pH值小于2.4大于1.2,提供了酸度适应的环境,Pb的浸出率,峰值由60%左右上升到90%以上,有明显升高。初始pH值在1.2到2.0之间,Zn浸出率峰值变化不大；矿浆初始pH值从2.0到2.8,Zn浸出率峰值减小；接种量在2%到5%之间,Pb、Zn浸出率峰值变化不大；接种量从5%到10%,Pb、Zn浸出率峰值剧增,接种量从10%到20%,Pb、Zn浸出率峰值变化不大。最后,用方铅矿和闪锌矿作为研究对象,模拟实际尾矿中的铅、锌硫化矿物,研究了方铅矿和闪锌矿的生物法浸出规律,考察了添加Fe2+对嗜酸性化能无机营养型微生物浸出方铅矿和闪锌矿的影响。结果表明,对于方铅矿和闪锌矿中Pb、Zn的浸出：添加嗜酸性化能无机营养型微生物比单纯的用酸更有利；在添加嗜酸性化能无机营养型微生物情况下,添加Fe2+比不添加Fe2+更有利。
[Abstract]:A great deal of tailings are produced in the process of dressing, which contains a lot of valuable metals, and is a kind of renewable resources.The sulfur content of metal sulphide tailings is high, so sulfur can be used as a nutrient source for the growth of acidophilic energy inorganic nutrient microorganisms, which provides the possibility for the bioleaching of sulphide tailings.The bioleaching of lead-zinc sulphide tailings can not only recover lead and zinc from tailings and realize the comprehensive utilization of resources, but also reduce the pollution of heavy metals from tailings to water environment and soil, which is of great economic and environmental significance.The main contents of this paper are as follows: screening of acidophilic energy inorganic nutrient microbes, analysis of tailings composition of lead-zinc sulphide ore, influence of leaching conditions on leaching rate of lead and zinc in sulphide tailings;Bioleaching of single minerals (galena and sphalerite).Firstly, the acidophilic energy inorganic nutrient microbes were screened from the tailings pit water of a tailings pool of lead and zinc sulphide ore. The conversion of Fe2 to Fe3 was determined to evaluate the oxidation activity of microbes.The samples of bioleaching tailings were collected from a tailings reservoir of lead zinc sulphide ore. The analysis of the mineral composition showed that the sulfur and iron contents were very high, mainly in the form of S2- and Fe2, which provided the living conditions for the acidophilic energy inorganic nutritious microorganisms.Then, the effects of HClH2SO4 and HNO3) on the leaching rate of lead and zinc in tailings were evaluated.The results show that the leaching effect of different acids on Pb leaching is from high to low to HClHl3H2SO4 and from high to low to H2SO4HClHNO3, which may be related to the concentration product of acid anion with Pb2 and Zn2 and the effect on the growth of tailings.Secondly, the effects of HCI on the leaching rate of lead and zinc in the tailings of lead-zinc sulphide ore were investigated under the conditions of solid liquid mass ratio, initial pH value of pulp and inoculation amount of different microorganisms.The results show that the higher the ratio of solid to liquid, the bigger the peak value of leaching rate of Pb, the later the time of the peak value, the smaller the peak value of leaching rate of Zn, the later the time of the peak value, and the higher the initial pH value, the larger the peak value of leaching rate of Pb.When the initial pH value of pulp is less than 2.4 > 1.2, the leaching rate of Pb in the environment suitable for acidity is provided, and the peak value increases from about 60% to more than 90%.The peak value of leaching rate of Zn from 2. 0 to 2. 0 was not changed, the peak value of leaching rate of Zn from 2. 0 to 2. 8% of pulp decreased, the peak value of leaching rate of Pb ~ (2 +) Zn from 2% to 5% was not changed, and the peak value of leaching rate of Zn from 5% to 10% was increased rapidly.The peak leaching rate of Pb ~ (2 +) Zn from 10% to 20% had little change.Finally, using galena and sphalerite as research objects, the bioleaching law of galena and sphalerite was studied by simulating the lead and zinc sulphide minerals in actual tailings.The effect of adding Fe2 on the leaching of galena and sphalerite by acidophilic energy inorganic nutrient microorganism was investigated.The results show that for the leaching of Pb ~ (2 +) Zn from galena and sphalerite, the addition of eosinophilic energy inorganic nutritious microorganism is more advantageous than that of pure acid, and the addition of Fe2 is more advantageous than that of no Fe2 under the condition of adding acidophilic energy inorganic nutritious microorganism.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X753

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