【作者】 廖国礼；

【导师】 吴超；

【作者基本信息】 中南大学 ， 安全技术及工程， 2005， 博士

【摘要】 资源与环境是人类赖以生存、繁衍和发展的基本条件,资源短缺、环境污染和生态恶化已越来越引起人们的普遍关注和重视。如何有重点地研究与开发有色金属生产和污染治理技术,促进我国有色金属工业与环境的协调发展,是国家高技术研究发展计划的重点研究领域之一,该课题研究具有重大的理论和实用价值。 论文从目前有色金属采矿活动中存在的重金属污染问题出发,以治理与控制矿区环境重金属污染为基本目标。在综述了大量的有关重金属污染研究文献的基础上,以湖南某有色金属矿山为研究对象,通过矿区水体和土壤的取样、化验和分析,对该矿重金属迁移规律进行了深入研究,并对矿区重金属污染进行了系统地评价。 论文的主要工作和获得的成果如下: 1、揭示了有色金属采矿活动将矿石从地下搬运到地表,并通过选矿和冶炼,使地下一定深度的矿物暴露于地表环境,改变了矿物的化学组成和物理状态,从而使重金属元素开始向生态环境释放和迁移,并产生严重的重金属污染的过程及规律。 2、建造了有色金属采矿活动过程重金属污染的事故树,通过对该事故树的定性分析,认为尾矿库是采矿活动重金属进入环境的主要污染源,在矿山治理和控制重金属污染时重点应放在尾矿污染区。 3、阐明了采矿活动中重金属向环境迁移过程首先是通过尾矿中硫化矿物的氧化使尾矿废水酸化,从而使重金属化合物在酸性条件下发生一系列的化学反应而开始的机理。应用地下渗流理论、多孔介质的水动力弥散理论,建立了尾矿AMD（Acid Mine Drainage）中重金属向土壤迁移的数学模型,对其进行了定量化分析。 4、通过对矿区土壤的标准化评价和重金属元素的相关性分析,认为该矿区土壤已受到了重金属的严重污染。矿区土壤Zn、Pb、Cd、Cu和As平均含量分别达2803.73 mg·kg^-1、1787.50 mg·kg^-1、5.37 mg·kg^-1、357.40 mg·kg^-1和46.61 mg·kg^-1,分别为参考的土壤环境背景值的29.20、21.90、0.83、13.10倍和0.71倍,Zn、Pb和Cu的污染相当严重,Cd、As的污染不明显。土壤重金属元素浓度之间都存在一定的正相关性。Pb与Zn之间相关性系数0.9,具有显著相关性。污染重金属元素之间的相关性在一定程度上反映了元素污染程度的相似性或污染元素有相似的来源。更多还原

【Abstract】 Resources and environment are the essential conditions on which human being could survive, breed and develop. Now, people pay more and more attention to and attach more importance to these questions such as lack resources, environmental pollution and ecological deterioration. How to study the nonferrous metal production and its pollution treatment technology and facilitate harmony development between nonferrous metal industry and environment is one of emphasis research areas of hi-tech project. Therefore, the research topic is very important both in theory and in practical values.In this research, a typical nonferrous metal mine was taken as studied object. Based on sample, test and analysis of the water and the soil near the studied object, the transport characteristics of heavy metals and pollution assessment in mining activities were investigated.In summary, the dissertation includes the following contents and contributions:（1） The process and behavior of release and transport of heavy metals in the mining area were explained in theory. Mining operation moves the valuable ores in underground to the surface. Mineral milling and metallurgical processes made the ores into new products of which the construction and chemical composition of minerals were changed. Consequently, during the processing, heavy metals will release and transport to ecological environment, which bring heavy metals pollution seriously.（2） By searching the process of mining activities, the fault tree of heavy metals pollution was built which indicates tailings are the most serious field of heavy metals pollution. The emphasis of preventing and controlling the heavy metals pollution of mine should be concentrated on the area of the tailings pollution.（3） The polluted mechanism could be explained as following: sulfide mineral oxidation of tailings produced waste water acidification, and then, a series of chemical reactions in acid condition occur which bring heavy metal ions to environment. Also, some mathematic models for describing the transport characteristics of heavy metals from acid mine drainage to soils were established, depended upon hydrodynamics, underground leakage theory and so on.（4） By analyzing the heavy metal concentrations and their correlation, it indicates that mining area has been polluted by heavy metals seriously. The average contents of Zn, Pb, Cd, Cu and As in soils of studied area are 2 803.73 mg·kg^-1, 1 787.50 mg·kg^-1, 5.37 mg·kg^-1, 357.40 mg·kg^-1 and 46.61 mg·kg^-1 respectively. They are 29.20, 21.90, 0.83, 13.10 and 0.71 times of environmental background values of soils. Among them, Zn, Pb and Cu pollution is very serious, and Cd and As pollution is unobvious. There was a positive correlation among heavy metals concentration. The correlated coefficient between Zn and Pb was 0.9, which indicates that the pollution status corresponds to the same polluted sources.（5） The system pre-estimation theory was used to establish the mathematic models for forecasting the heavy metal concentration of pollution in tailing area based on the history measuring data from 1994 to 2002. The forecasting results show that Pb, Zn, Cd and As concentrations near the tailing dam in 2022 will reach 1.191².710 times compared with the case in 2002.（6） Three-step extraction procedure set by European Bureau of Reference was applied to extract heavy metals fractionation of the soils. The testing results show that heavy metals are thedominant status in associated with residual fraction and least associated with reducible fraction. Lead and zinc are primarily associated with the residual fraction of 61.5% and 43.0% respectively.（7） Intimated method and synthetic index were applied to assess a polluted river near the mine. The assessment result indicates the river has been polluted by heavy metals which synthetic index is 25.08. The contamination of Pb2+ and Zn2+ is rather serious.（8） Depending upon the polluted features of various mining activities in the mine, the contaminated soil area was divided into four zones which were polluted by tailings, mine drainage, dust deposition in wind and spreading minerals during vehicle transportation respectively. Ranking of pollution intension of different zones from heavy to light is in the sequence of tailing zone, mineral transportation zone, mine drainage zone, and dust deposition zone. The Nemero indexes are 177.60, 65.54, 9.76 and 8.99 respectively, which show the pollution intension of tailings is the heaviest.（9） The ecology risk assessment index in the mine was computed. The heavy metals toxic response coefficient and ecology harm coefficient were also calculated and discussed. The average ERI （ecology risk index） among 28 samples was 418.26. The general environmental quality of studied area became considerabe deterioration. Risk of heavy metals pollution is very high in the mine.（10） Some policy suggestions for preventing and controlling the environmental pollution by heavy metals in mining activities were put forward, which claimed the most effective approach is to increase the mineral processing recovery ratio and reduce discharge of the tailings in order to prevent heavy metal contamination. Nowadays, the key measure is to disseminate scientific knowledge of preventing and controlling environmental pollution by heavy metals, encourage and support scientific research and technological development, and expand the scope of mine environmental impact assessment. Meanwhile, the state should promulgate feasible policies to encourage and support the comprehensive recovery and rational utilization of tailings, and adopt economic and technical policies and measures that facilitate the comprehensive use of tailings.更多还原