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《吉林大学学报(地球科学版)》2015,(Z1)
<正>金属硫化物矿山环境中大量暴露于地表的金属硫化物(如黄铁矿、方铅矿、闪锌矿、黄铜矿)会发生氧化而生成酸性矿山排水(AMD)。尾矿和废石中的碳酸盐矿物往往与AMD反应而溶解,同时使AMD的酸度下降,并形成多种具有固定重金属元素能力的次生矿物,因此,碳酸盐矿物常常被作为治理AMD污染的重要矿物材料。由于方解石和黄铁矿广泛存在于多种岩石类型中,岩石露头的地表风化作用常常存在硫化物氧化分解、酸性岩石排水(ARD)形成、碳酸盐矿物分解、次生矿物形成的连续过程,这一过程 相似文献
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铜陵矿山酸性排水及固体废弃物中的重金属元素 总被引：8，自引：0，他引：8
在调查中国铜陵凤凰山铜矿和新桥硫铁矿两种不同类型矿山固体废弃物特征的基础上,研究了矿山尾矿和废石产生酸性排水的可能性及其差异以及矿山固体废弃物中重金属元素的赋存形式。结果表明,凤凰山铜矿的尾矿基本不产生矿山酸性排水,而新桥硫铁矿采矿废石产生矿山酸性排水,并且凤凰山铜矿的尾矿和新桥硫铁矿采矿废石中重金属元素的赋存形式也有差异,前者重金属Cu、Pb、Zn、Cd、As、Hg主要赋存于硅酸盐态中,而后者在还原态中有较高的含量,这反映了在地表条件下尾矿中大量重金属元素已经发生了迁移,而采矿废石已经开始氧化,且酸性排水的存在更有利于废石中重金属元素的迁移和扩散,进而导致矿区周围环境的污染。 相似文献
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从硫化物的氧化、脉石矿物的溶解、氧的扩散、水的流动和溶质质量迁移等过程的耦合作用建立了尾矿-水相互作用的动力学模型。对湖南湘西金矿尾矿库的数学模拟表明：早期尾矿-水的相互作用可以引起酸水的产生和重金属的释放及对环境的污染，影响较大的主要是前30年，随着时间增加，尾矿孔隙水逐渐中性化，污染元素含量显著降低。脉石矿物的溶解和有机物反应可降低尾矿中氧的扩散和产生酸的中和作用。尾矿库上部孔隙水中各组分含量明显高于尾矿库下部，并在约6m深处存在突变带。尾矿库的水文分带是导致地球化学分带的主要原因。 相似文献
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《吉林大学学报(地球科学版)》2015,(Z1)
<正>近年来,矿山开采带来的环境污染问题日益严重,矿区内的尾矿坝及露天堆放的废石堆、矿石堆是矿区周围及其下游环境中重金属元素的主要来源,天然雨水淋溶浸泡作用对重金属元素的释放迁移具有一定的促进作用[1],因此,对尾矿、废石、矿石的模拟淋滤实验能够揭示污染源中矿物的分解转化规律、水-岩氧化还原反应机理、重金属元素在水-岩中的迁移转化规律以及影响因素等,从而能够为矿山环境污染 相似文献
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矿山-河流系统中重金属污染的地球化学研究 总被引：4，自引：0，他引：4
立足于矿山及纳污河流生态系统,从重金属污染源研究入手,分析了尾矿重金属淋滤释放规律和影响因素;阐述了重金属在矿山及相关河流系统中的迁移、转化和富集过程及其对生态环境的影响;总结和评述了现有的矿山环境重金属污染的评价方法,指出了今后的研究重点:努力减少尾矿中重金属向环境释放,逐步实现矿床的无废开采;设计不同条件和影响因素下的尾矿淋滤实验,加强酸性废水和尾矿重金属淋滤释放规律的研究,建立酸性矿山废水和重金属释放的预测模型;运用微量元素、稀土元素和高精度的Pb、S同位素测试手段,示踪重金属的来源及其运移途径;运用3S技术和高新技术手段提取和识别环境地球化学信息,加强矿山-河流系统重金属污染及其生态环境影响的监测;运用地球化学工程技术和植物修复技术治理矿山环境及其影响流域的污染。 相似文献
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矿山开采、选冶等活动将大量废弃物排放至环境中,尤以矿山尾渣和酸性矿山排水为显著,致使大量有毒有害元素暴露在空气和水中并被释放出来,直接或间接危害其周围的环境.矿山重金属的释放途径主要包括尾矿渣的氧化淋滤以及正在作业的选厂排水,其释放的重金属绝大部分都进人到水环境中. 相似文献
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采矿活动影响较小的范围，但对环境会有大的局部影响，采矿场金属主要以酸性矿山排水、废石堆和尾矿堆积的侵蚀等形式释放。对预测酸性矿山排水释放金属的有效方法进行了简单回顾。 相似文献
10.
酸性矿坑废水对流域酸化的影响——以贵州兴仁县典型废弃煤矿区小流域为例 总被引：4，自引：0，他引：4
人们在开采使用矿产资源的同时,堆弃大量含有硫化物的废弃矿石和废渣于周围环境中。矿山环境中因硫化矿物氧化,导致采矿产生大量的酸性矿坑排水。这种水体具有低pH值,高电导率,高硫酸根和高重金属含量的特征。酸性矿坑排水对下游水生生物及植物等具有很强的毒性,大量排放引起的环境问题受到广泛关注。为了了解酸性矿山排水对流域水体和土壤的影响,本文选择位于贵州省西南部兴仁的一个典型废弃煤矿区进行研究,通过测定矿坑排水、水库水、河水的pH值和EC,以及土壤的pH值,分析矿坑排水、地表水以及土壤pH值的空间变化情况,在此基础上对矿坑排水对流域酸化的影响进行了综合评价。调查结果表明,酸性矿坑排水和受其影响的水库水体的电导率很高,且pH值均小于3。研究区域地表水（水库水、河水）本底水化学类型为Ca2+-HCO3-型,其pH值在7左右,反映了流域内有碳酸盐岩广泛分布的自然环境特征。当受到酸性矿坑排水影响后,水化学类型转变为Ca2+-SO42-型,pH值则低于4.0。通常,酸性矿坑排水在流动过程中与河床的碳酸盐岩发生中和反应,促使水体的pH升高。野外考察发现,研究区河道中碳酸盐岩中空易碎,其CaCO3成分因长期与酸性矿山排水发生反应而被耗尽。同时,在氧化条件下,酸性矿坑排水中的铁在流动过程中生成大量的氢氧化物覆盖了沿程的河床。这种覆盖作用抑制了酸性矿山排水进一步与碳酸盐岩发生中和反应。因此,在研究区分布有广泛的碳酸盐岩情况下,受酸性矿坑排水影响的河水到下游5 km处仍保持较低的pH值。研究区的主要农作物是水稻,其灌溉水源主要是水库水。为了了解酸性矿坑排水对土壤的影响,对水库下游流域土壤pH值的空间分布进行普查,统计其出现的频率。结果表明,以受酸性矿坑排水影响的水库水作为灌溉水源的土壤,其表土的pH值较低,平均值在5.0左右。反之,土壤表土的pH值平均值在6.5左右。此外,通过对受到酸性矿坑排水影响显著的土壤进行剖面调查,发现从地表到深度90 cm的土壤的pH值均小于4.0。结合受酸性矿坑排水影响的河水pH值普遍偏低的情况可以推测流域酸化与酸性矿坑排水有密切关系。 相似文献
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The extraction of mineral resources requires access through underground workings, or open pit operations, or through drillholes for solution mining. Additionally, mineral processing can generate large quantities of waste, including mill tailings, waste rock and refinery wastes, heap leach pads, and slag. Thus, through mining and mineral processing activities, large surface areas of sulfide minerals can be exposed to oxygen, water, and microbes, resulting in accelerated oxidation of sulfide and other minerals and the potential for the generation of low-quality drainage. The oxidation of sulfide minerals in mine wastes is accelerated by microbial catalysis of the oxidation of aqueous ferrous iron and sulfide. These reactions, particularly when combined with evaporation, can lead to extremely acidic drainage and very high concentrations of dissolved constituents. Although acid mine drainage is the most prevalent and damaging environmental concern associated with mining activities, generation of saline, basic and neutral drainage containing elevated concentrations of dissolved metals, non-metals, and metalloids has recently been recognized as a potential environmental concern. Acid neutralization reactions through the dissolution of carbonate, hydroxide, and silicate minerals and formation of secondary aluminum and ferric hydroxide phases can moderate the effects of acid generation and enhance the formation of secondary hydrated iron and aluminum minerals which may lessen the concentration of dissolved metals. Numerical models provide powerful tools for assessing impacts of these reactions on water quality. 相似文献
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Acid neutralization mechanisms and metal release in mine tailings: a laboratory column experiment 总被引：1，自引：0，他引：1
Jasna Jurjovec Carol J. Ptacek David W. Blowes 《Geochimica et cosmochimica acta》2002,66(9):1511-1523
Mining and milling of base metal ore deposits can result in the release of metals to the environment. When sulfide minerals contained in mine tailings are exposed to oxygen and water, they oxidize and dissolve. Two principal antagonistic geochemical processes affect the migration of dissolved metals in tailings impoundments: sulfide oxidation and acid neutralization. This study focuses on acid neutralization reactions occurring in the saturated zone of tailings impoundments. To simulate conditions prevailing in many tailings impoundments, 0.1 mol/L sulfuric acid was passed continuously through columns containing fresh, unoxidized tailings, collected at Kidd Creek metallurgical site. The results of this column experiment represent a detailed temporal observation of pH, Eh, and metal concentrations. The results are consistent with previous field observations, which suggest that a series of mineral dissolution-precipitation reactions control pH and metal mobility. Typically, the series consists of carbonate minerals, Al and Fe(III) hydroxides, and aluminosilicates. In the case of Kidd Creek tailings, the dissolution series consists of ankerite-dolomite, siderite, gibbsite, and aluminosilicates. In the column experiment, three distinct pH plateaus were observed: 5.7, 4.0, and 1.3. The releases of trace elements such as Cd, Co, Cr, Cu, Li, Ni, Pb, V, and Zn were observed to be related to the pH buffering zones. High concentrations of Zn, Ni, and Co were observed at the first pH plateau (pH 5.7), whereas Cd, Cr, Pb, As, V, and Al were released as the pH of the pore water decreased to 4.0 or less. 相似文献
14.
Mine tailings integrated investigations: The case of Rio tailings (Panasqueira Mine, Central Portugal) 总被引：1，自引：0，他引：1
Mining generates huge quantities of waste materials from ore extraction and milling operations, which accumulate in tailings and open impoundments. The risks associated with mine tailings have different nature, namely stability, rupture, surface and groundwater contamination, acid mine drainage (AMD) and precipitation of secondary minerals. In fact catastrophic failure of tailings impoundments has occurred, transporting slurry, dissolved metals and fine reactive metal particles to the environment.Often deposition conditions of old mine tailings are unknown and monitoring is deficient or even inexistent. Thus, in order to prevent accidents it is necessary to establish the internal structure, that is, mapping tailings impoundment, internal sediment structures – limits and stratigraphy – seepage and pathway locations, bedrock depth and topography estimates and actual deposition conditions of the tailings. Owing to the complexity of the problem, only integrated approaches can investigate and monitor comprehensively the characteristics and evolution of mine tailings and its impacts on the environment.As this is a multidisciplinary problem, strategies should consider integrated studies such as Geophysics, Geochemistry and borehole surveys. However data from these sources must be interpreted together, in a GIS database, to provide better models and an enhanced overall knowledge of the studied structures.It is proposed to test and validate such a methodology in a case study, Panasqueira mine, central Portugal and to contribute to the decision-making process of environmental and civil protection agencies with responsibilities in the assessing, prevention, mitigation, and controlling the potential and actual effects of tailings spills on the environment. 相似文献
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《Applied Geochemistry》2005,20(3):661-667
This paper describes the geochemical testing of mine tailings sourced from the Black Swan Ni Mine located near Kalgoorlie, Western Australia. Acid–base accounting was used to provide an indication of the acid generating capacity of two kinds of mining tailings: disseminated-ore tailings from the Cygnet Tailings Dam Storage Facility (CTDSF) and massive-ore tailings from the Silver Swan Tailings Dam Storage Facility (SSTDSF). All of the tailings in SSTDSF have acid generating potential which is consistent with previous research reports. New findings in this paper reveal that approximately 16% of the tailings in CTDSF have the potential to be acid generating. In contrast, previous reports state that the disseminated-ore tailings are classified as non-acid forming. Most of the potential acid generating tailings in the CTDSF are found in the upper-middle sections of the tailings profile, but some are located at the bottom of the tailings dam. The upper-middle section of the tailings is oxidized because these tailings have interacted with atmospheric O2 and rain and surface water. Oxidation of the bottom tailings in the CTDSF may be due to infiltration of ground water into hidden fractures under the east bank of CTDSF, which caused these tailings to oxidize under closed and reduced conditions.The acid drainage in the tailings dam storage facility was observed 3 a, after the development of the Black Swan Nickel project. This delayed production of acid drainage was likely due to the slow rates of acid neutralization provided by alteration gouge minerals such as Mg/Fe-carbonates (magnesite–siderite series) associated with the Ni ores. The acid drainage leaking from the tailings dams has contaminated neighboring ground water via increased acidity and heavy metals.Because of the potential acid generation in some of the disseminated ore tailings, it is inadvisable to use disseminated ore tailings as cover materials in the storage facility to isolate the underlying potentially-acid-forming tailings from O2 and water, as proposed by previous research reports. 相似文献
16.
Pham Tich Xuan Nguyen Van Pho O. L. Gas’kova S. B. Bortnikova 《Geochemistry International》2013,51(11):931-938
This study provides an assessment of the environmental impact of open pit mining operations at the Cay Cham titanomagnetite-ilmenite deposit (northern Vietnam). The results of surface water sampling indicate the formation of acid mine drainage and contamination of adjacent areas by heavy metals (Cu, Zn, Ni, and Mn). The acid mine drainage is produced by oxidation leaching of sulfide minerals associated with primary mineralization owing to the low neutralization potential of the natural waters in the humid environment of tropical rainforest. The study showed that alternating dry and wet seasons typical of this climatic region promote the generation of stored acidity leading to a sharp decrease in pH of drainage water during the wet season and result in the negative impacts of this mine on both flowing and stagnant surface waters. 相似文献
17.
Acid mine drainage is an environmental problem produced when sulphide in mine tailings dams comes in contact with O2, bacteria and water. Oxidation occurs and a succession of reactions is responsible for producing acid and metals in the environment. One solution proposed is to use red mud bauxite (RMB) that is very alkaline to neutralise acidic tailings. Previous experiments showed that RMB has a good neutralisation capacity for a short time, but the long-term neutralisation potential is uncertain. So brine was added to RMB to verify if it can improve long-term alkalinity retention of RMB. Some authors have presented results where seawater or other natural or artificial Ca- and Mg-rich brines were used with RMB to convert the basicity (mainly NaOH) and other soluble alkalinity into low solubility hydroxide, carbonate and hydroxycarbonate minerals. Results showed that neutral pH conditions were maintained over the entire test for RMB and a mixture of RMB with brine. Addition of brine to RMB slightly lowered the pH compared to RMB alone. RMB alone lost a lot of dissolved alkalinity at the beginning of the test. Most of the alkalinity was lost in water after a few flushes for RMB samples. The addition of brine helped to keep neutralisation potential over more cycles of leaching. 相似文献
18.
Acid Mine Drainage and Heavy Metal Pollution from Solid Waste in the Tongling Mines, China 总被引：2，自引：0，他引：2
Based on investigation of the characteristics of solid waste of two different mines, the Fenghuangshan copper mine and the Xinqiao pyrite mine in Tongling, Anhui province in central-east China, the possibility and the differences of acid mine drainage （AMD） of the railings and the waste rocks are discussed, and the modes of occurrence of heavy metal elements in the mine solid waste are also studied. The Fenghuangshan copper mine hardly produces AMD, whereas the Xinqiao pyrite mine does and there are also differences in the modes of occurrence of heavy metal elements in the railings. For the former, toxic heavy metals such as Cu, Pb, Zn, Cd, As and Hg exist mostly in the slag mode, as compared to the latter, where the deoxidization mode has a much higher content, indicating that large amounts minerals in the waste rocks have begun to oxidize at the earth surface. AMD is proved to promote the migration and spread of the heavy metals in mining waste rocks and lead to environmental pollution of the surroundings of the mine area. 相似文献
19.
Sudhakar M. Rao B. V. Venkatarama Reddy 《Geotechnical and Geological Engineering》2006,24(6):1545-1559
The gold mining process at Kolar gold field (KGF) mines has generated about 32 million tons of tailings. Gold was extracted
from the mined ores using cyanidation technique that involved dissolution of gold in the ore by water soluble alkali metal
cyanides (example, sodium cyanide or potassium cyanide). Of the several dumps that received the mine tailings only the Kennedy’s
Line dump was active prior to closure of the KGF mines in the year 2000. The Kennedy’s Line dump received sulfide bearing
tailings in slurry form that comprised of spent ore and process water bearing soluble alkali metal cyanide. Depending on the
pH of the tailing slurry, the free cyanides may exist as aqueous hydrogen cyanide that can escape to the atmosphere as hydrogen
cyanide gas or occur as soluble cyanide (CN−) ions that can be leached by infiltrating water to the sub-surface environment. Additionally, the presence of pyrite minerals
in the Kennedy’s Line dump makes them susceptible to acid drainage. This study examines the potential of gold tailings of
Kennedy’s Line dump to release cyanide ions (CN−) and acid drainage to the sub-surface environment by performing physico-chemical and leaching tests with tailing samples
collected from various depths of the dump, sub-surface soil samples beneath the dump and groundwater samples from vicinity
of Kennedy’s Line dump. The chemical mechanisms responsible for the ambient cyanide and pH levels of the tailing dump, sub-surface
soil samples and groundwater are also inferred from the laboratory results. 相似文献