澳大利亚尾矿治理现状及先进技术综述

澳大利亚在尾矿治理方面拥有先进的技术,处于国际领先水平,并提出了基于风险的矿山生命周期法,确保尾矿对环境造成的风险控制在可接受的低水平内。介绍了澳大利亚在尾矿治理方面的普遍性经验,主要包括尾矿浓缩、尾矿覆盖系统的设计以及尾矿的植被恢复。并在此基础上总结了澳大利亚尾矿治理的先进技术,包括脱水尾矿、联合处置、膏体石、空穴充填、地貌恢复及尾矿回收等环节,并且以澳大利亚3个矿区为例,证明了这些先进技术的可行性。     

Reducing mine water requirements

Mining is a water intensive activity, and reducing water consumption is a key requirement in moving toward a more sustainable mining industry. This paper identifies mine water reduction, reuse and recycle options, and demonstrates cases where these options have been implemented around the world. A mine water system model is developed and used to show potential water saving strategies through six scenarios. Apart from the base case, these scenarios include the introduction of evaporation reduction strategies, paste tailings disposal, filtered tailings disposal, ore pre-sorting and a combination of the most effective options. The results of the modeling show how an open-pit copper mine with a traditional layout can move from having an average water withdrawal of 0.76 m³/t of ore processed to 0.20 m³/t of ore processed or lower. A key result of the modeling is the discovery that a combination of ore pre-concentration and filtered tailings disposal can reduce water consumption by 74% or more. This finding demonstrates an opportunity to significantly lower water consumption on mine sites.     

LCA of comprehensive pig manure management incorporating integrated technology systems

Increased and intensified pig production has raised the needs for proper management systems of pig manure in order to reduce negative environmental impacts. The objectives of this study were to identify the most significant environmental impacts from pig manure management considering a wide range of impact categories and to determine which integrated technology system at which handling stage can achieve the highest impact reduction. Twelve scenarios applying various treatment, storage and land application systems were developed and compared. Life cycle assessment (LCA) with the aim of capturing the actual consequences of the considered scenarios was selected as the tool for impact quantification. The most important impact categories in this investigation are global warming (GWP), aquatic eutrophication (AEP), respiratory inorganics (RIP), and terrestrial eutrophication (TEP). The two latter impacts, caused by ammonia emissions, have not been widely considered in most of previous LCA studies on pig manure management. The main keys for the effective impact reduction are the integration of treatment technology systems aiming at energy recovery with high nutrient recovery and control of greenhouse gas, ammonia, and nitrate emissions at every handling stage. For GWP and AEP, the anaerobic digestion-based scenario with natural crust storage achieves the highest impact reduction because of high efficiencies in energy and nutrient recovery with restricted emissions of GHG and nitrate. For RIP and TEP, the incineration and thermal gasification based scenarios and the scenario without a treatment system applying the deep injection method yield the highest impact minimisation due to the lowest ammonia emissions. This study further indicates the need to consider all significant impacts to decide the best management options taking into consideration local conditions.     

Optimisation of the mine closure process

The excitement and fanfare that surrounds the opening of a new mine is never present when it finally closes. Closure may be planned but most commonly, it is premature, occurring before ore (or coal) reserves are exhausted. The reasons why mines close are diverse and include economic, geological, geotechnical, regulatory, community and other pressures. Premature and planned mine closures can result in significant adverse impacts on the environment and community and need to be managed appropriately.The use of risk management techniques can help reduce these impacts. The closure risk model has significant potential as a tool for decision-makers to assess the major closure risks at individual mine sites in a structured, systematic manner both qualitatively and quantitatively. This, in turn, facilitates comparisons between the closure issues at a single site as well as between different mines. A team-based approach is essential to ensure that all of the risks are incorporated, and the use of an external facilitator, as is standard practice in risk assessments, helps to reduce subjective bias. The importance of community engagement during operation and the inevitable mine closure phases cannot be overstated. If ignored, an optimal closure outcome will not be achieved. The consequences of a poor consultation strategy are potentially severe in terms of community impacts. Mining companies that get it right will benefit from the support they receive from employees, landholders, local and state governments, and other stakeholders. Other benefits include significant cost savings and a competitive advantage for future exploration/mining activities.Even though closure issues are unique from mine-to-mine, it is possible to develop a series of principles to assist the company, government and community involved in the closure process to ensure maximum benefit for all parties involved.     

Compatibility of slurry wall backfill soils with acid mine drainage

The use of slurry walls to contain oxidized tailings and provide cutoff below tailings dams is generally a cost-effective way of preventing environmental degradation due to seepage of acid water from tailings areas. Long-term environmental protection dictates that the slurry wall materials be compatible with the acid water. Six percent Avonseal bentonite by weight was added separately to two natural soils to represent slurry wall backfill materials, which were then permeated with several pore volumes of acid mine drainage (AMD) in the laboratory. Results using both flexible wall and fixed wall permeameters were similar. The carbonate-rich backfill gave an average hydraulic conductivity (K) of 1×10⁻⁹ cm/s, buffered the AMD at circumneutral pH, and kept effluent metal concentrations to very low values (for example, less than 0.05 mg/l zinc). Although the carbonate-free backfill also maintained low K (average 3×10⁻⁸ cm/s) during AMD permeation, it could not neutralize the AMD as effluent pH decreased to approximately 3.5, and metal concentrations reached those of the influent or permeant after approximately 17 pore volumes.     

Contributions to eco-design of machine-to-machine product service systems: the example of waste glass collection

Efficient waste management is necessary in order to face up to increasing quantities of waste generated in modern societies. A technical solution using a Machine-to-Machine (M2M) enhanced Product-Service System (PSS) for bring-in waste glass collection is identified. Methodology based on Life Cycle Analysis (LCA) is proposed. The results help understand the mechanisms of M2M PSS. Possible improvements are explored and the study shows how the PSS infrastructure impacts the environment. It examines the influence of major organisational parameters and contributes to eco-design and dimensioning of the M2M PSS. It reveals the interest of mutualisation to reduce environmental impacts and shows the importance of limiting data exchanges. It argues for the use of multi-criteria LCA on the complete system including the telecom infrastructures and employs realistic use scenarios derived from field studies.     

污水处理厂环境影响的生命周期分析

生命周期分析技术除了强调污水处理工艺对于污水处理以及污泥的处理和处置必须具有令人满意的功能以外，还强调它们产生的其他方面的重要环境影响，涉及污水厂的能源管理，污水厂的设计，原材料管理以及有关污水厂的总体环境政策。每一种污水处理工艺在净化污水的同时，在其他 施工建设，生产运行和报废拆毁的三个阶段中均存在能源的使用以及污染物的排放问题。     

广西大厂多金属矿区河流中Sb和As的迁移及环境影响

以广西大厂多金属矿山为例,对其矿山尾矿堆及地表河流进行采样,研究矿山开采中释放的毒害元素Sb和As对河流水环境的影响. 结果表明,矿渣堆中的w(Sb)和w(As)分别为175～7 119和309～24 233 mg/kg;选厂排水中ρ(Sb)和ρ(As)最高值分别为5 475和179 μg/L;受矿山影响的河流中的ρ(Sb)和ρ(As)平均值在枯水期为630和100 μg/L,在丰水期为497和65 μg/L. 该矿山的开采致使选厂排水和矿山尾渣均对矿区河流中重金属含量做出显著贡献,已对周边河流产生严重影响,造成了刁江上游河水的污染. Sb与As虽然化学性质相似,但二者在河水中的迁移特性仍有明显的差别,As在河水中的衰减强于Sb. 河水中Sb和As的影响范围都很大,模拟计算表明,Sb和As的影响范围分别离矿山区约120和60 km.      

Towards sustainability in urban water: a life cycle analysis of the urban water system of Alexandria City,Egypt

Urban water authorities and water planers in many countries are struggling to satisfy the growing urban water and sanitation demands, while at the same time achieving sustainability of the urban water system. This research focused on the assessment of the environmental impact of today's Alexandria's urban water system and on the identification of options to improve the sustainability of the system. Therefore, a life cycle assessment (LCA) methodology was used. The urban water system was modelled using SimaPro software, and the impacts of various options on the system were analyzed based on the Eco-indicator 99 assessment method. The results show that the highest impact in today's system is generated by the disposal of primary treated wastewater (68% of the total impact) and by high-energy-consuming water treatment plants (18% of the total impact). The research assessed different scenarios for improving the environmental performance of the system and a paradigm shift (decentralization and separation at-source of different kinds of household wastewater) was found to be the preferred long-term scenario.     

Climate change scenarios to facilitate stakeholder engagement in agricultural adaptation

To prepare agricultural systems for climate change, scientists need to be able to effectively engage with land managers and policy makers to explore potential solutions. An ongoing challenge in engagement is to distil the complexity of climate-change-management-change interactions in agro-ecological systems to identify responses that are most important for adaptation planning. This paper presents an approach for selecting climate change scenarios to provide a focal point for engaging with stakeholders to evaluate adaptation options and communicate assessment outcomes. We illustrate how scenarios selected with the approach can be used by evaluating climate change impacts and an adaptation option for livestock industries in the north-east Australian rangelands. Climate change impacts on forage production, animal liveweight gain and soil loss are found to track projected climate changes in four pasture communities; increasing by up to 50% and declining by up to 110% in response to doubled atmospheric carbon-dioxide (CO₂), 4°C warming, and +20% to ?40% changes in mean annual rainfall. The effectiveness of reducing grazing pressure as an adaptation option shows a similar response; resulting in higher forage production (up to 40%), animal liveweight gains (up to 59%) and gross margins (up to 40%), and reduced soil erosion (down by 91%) per hectare relative to the baseline management. The results show that a few key scenarios may be selected to represent the range of global climate model (GCM) projections for use in assessing and communicating impacts and adaptation; simplifying the assessments and allowing limits to the effectiveness of adaptation options to be explored. The approach provides a framework for capturing and communicating trends in climate change impacts and the utility of options, which are required for successful engagement of stakeholders in finding viable adaption responses.     

Assessment of future scenarios of climate and land-use changes in the IMPRINTS test-bed areas

The main objective of this work is to identify and evaluate the potential impacts produced by climate and land-use changes in six European test-bed basins (Llobregat, Guadalhorce, Gardon d’Anduze, Linth, Verzasca and Sambuco). Data to build future scenarios that can modify the different basins’ flash flood and debris flow risk level has been analyzed in this paper. High resolution climate scenarios have been obtained from several European projects and/or National initiatives, depending on each case. Climatic variables have been widely analyzed, with a special focus on extreme precipitation. Typical generalized extreme value (GEV) distributions have been fitted to observed and projected rainfall data to assess impacts in the frequency distributions of extreme rainfall up to 2100. Regarding climate, the main conclusion is the importance of using data at the maximum spatial and temporal resolution applying downscaling methodologies adapted to basin scale (test-bed areas ranging from approx 200 to 5000 km²) and oriented to obtain extreme rainfall values.In general, high variability has been detected, obtaining very different results for the different models and scenarios. Data corrections may lead to better representations of present situations and, therefore, more reliable future projections, but currently some of them are not suitable for extreme precipitation assessment.Regarding land-use changes, a cellular automata-based model has been used (MOLAND) to simulate the 2000–2040 period taking the CORINE land-use dataset as input data. Llobregat, Guadalhorce and Gardon d’Anduze basins have been identified as potentially interesting for simulating urban land-use dynamics due to the existence of important urban areas within their limits. The assessment of the rural land-use changes has been carried out using the results from the EURURALIS project (2000–2030 period), available for all the basins.The results of this paper are framed in the FP7 project IMPRINTS that has the aim of analyzing impacts of future changes to provide guidelines for mitigation and adaptation measures and, in general, to improve the application of the EC Flood Risk Management Directive.     

乐昌铅锌尾矿的酸化及重金属溶出的淋溶实验研究

利用淋溶实验，研究了乐昌铅锌尾矿的酸化及其对重金属溶出的影响。结果表明：高硫和中硫尾矿因含很高的有效硫（分别为２０．４％和１５．９％），在尾矿的堆放过程中会发生酸化，发生酸化的时间在第５１周左右，低硫尾矿（有效硫为７．２％）在短期内不会发生酸化。尾矿发生酸化后，将促进其中盐份的溶解，从而使得Ｐｂ、Ｚｎ和Ｃｕ等重金属的溶出增高。本研究可为铅锌尾矿的环境管理提供科学依据     

金属矿山采选项目的环境管理制度执行情况及问题分析

介绍了金属矿山项目的一般环境影响及特殊环境影响,通过识别金属矿山的特殊环境影响,以金属矿山尾矿库溃坝事故为例,对金属矿山项目环境管理制度执行情况及在管理过程中存在的问题进行了分析。尽管在矿山开采建设及服务过程都伴随着环境制度的监管,但是在实际运行过程中仍会出现不同的问题,产生环境污染影响与生态影响。因此,识别出金属矿山项目采选易发生的环境问题,在开发矿产资源的同时做好矿山环境保护及管理工作、加强矿山环境制度建设及环境监管是非常必要的。     

大厂矿区锡矿尾砂对银合欢生长的影响研究

大厂矿区锡矿尾砂含有多种有毒有害物质 ,尤其是重金属As、Cd、Zn ,严重限制了植物的自然定居与生长。筛选能适应如此恶劣的条件的植物种类和对尾砂进行适当的改良是锡矿尾砂库植被恢复与重建成功与否的关键。在温室内进行的银合欢栽培实验表明 ,城市垃圾肥能较好地改善尾砂的理化性质 ,可以起到替代土壤的作用 ;银合欢在尾砂含量和垃圾肥含量各为 50 %并添加适当磷肥的组合中生长良好 ,可以作为大厂矿区锡矿尾砂库植被恢复与重建的优选植物。     

广东凡口Pb-Zn尾矿中重金属的表生地球化学行为及其对矿山环境修复的启示

通过分级提取实验 ,结合矿物成分和化学成分分析 ,对广东凡口铅锌尾矿的新尾矿和 1号尾矿库不同氧化程度尾矿的矿物组成、重金属含量及其形态进行了研究和对比 .新尾矿中的黄铁矿含量很高 (约 3 1% ) ,铅锌的含量分别高达 0 7%和 1 2 %以上 ,重金属元素主要赋存于金属硫化物中 .1号尾矿库样品中的黄铁矿含量 <10 % ,重金属元素也明显低于新尾矿 .在表层氧化带 (硬化层 ) ,硫化物的快速氧化导致大量次生矿物沉淀 ,锌大量吸附于 (氢 )氧化铁表面 ,可迁移性大 ;铅则主要形成次生难溶矿物 (如铅矾 ) ;次氧化带以硫化物的缓慢淋溶作用为主 ,难以形成次生矿物 ,Pb、Zn的流失比例大于 70 % .常用于矿山环境治理的尾矿覆盖方法往往使尾矿处于次氧化环境 .上述研究结果表明 ,这些方法不一定能够阻滞污染元素的迁移 .此外 ,本次研究采用Dold提出的分级提取法 ,发现方铅矿的溶解主要发生在第 2步 (提取液 :pH =4 5 ,1moL L- 1 NH4 Ac) ,而其它硫化物的溶解主要在第 6步 ,这可能是Ac- 与Pb2 + 的络合作用所造成的 ,表明提取液中含Ac- 的分级提取方法不宜用于评价铅的活性     

中国电动自行车动力铅酸蓄电池生命周期评价

以近年来中国用量增长最快的电动自行车动力铅酸蓄电池为对象,建立了生命周期环境影响评价模型,分析了从原材料生产、电池生产、电池运输、电池使用和废旧铅酸蓄电池及含铅废物回收处理全生命周期的环境影响.研究采用了大量企业调研数据和中国本土LCA数据库,以期反映整个中国铅酸蓄电池产业链的技术工艺和环境管理水平现状.结果表明,原材料生产和电池使用是资源(含能源)消耗的主要阶段,贡献了电池全生命周期绝大部分的环境影响.原材料生产贡献最多的全生命周期环境影响包括非生物资源耗竭(699%)、富营养化(89%)、光化学烟雾(98%)、臭氧层破坏(117%)、人体毒性(159%)和生态毒性(484%).电池使用过程的电耗间接消耗了83%的一次能源,相应地贡献了最多的气候变暖潜值(86%)和酸化潜值(70%).废旧铅酸蓄电池和含铅废物回收再生铅可抵消很大一部分原材料生产造成的环境影响.延长电池寿命,减少电池生产金属用量及提高废旧电池回收处理过程的工艺技术和污染控制水平也是减少铅酸蓄电池生命周期环境影响的关键.     

生命周期评价在工农业生产中的应用研究

生命周期评价是指产品在整个生命周期中对环境的影响、对物质和能源的投入、产出进行汇集、测定的系统方法。从产品生命周期评价的发展过程和技术框架入手,对生命周期评价的意义以及工农业生产中的应用进行探讨,着重阐述了生命周期评价在农业生产、环保工艺、节能减排、清洁生产和环境管理中的应用。并认为生命周期评价应广泛用于环境治理领域,这是解决社会生产发展和环境污染之间矛盾的主要手段。     

Land use as a mitigation strategy for the water-quality impacts of global warming: a scenario analysis on two watersheds in the Ohio River Basin

This study uses an integrative approach to study the water-quality impacts of future global climate and land-use changes. In this study, changing land-use types was used as a mitigation strategy to reduce the adverse impacts of global climate change on water resources. The climate scenarios were based on projections made by the Intergovernmental Panel on Climate Change (IPCC) and the United Kingdom Hadley Centre's climate model (HadCM2). The Thornthwaite water-balance model was coupled with a land-use model (L-THIA) to investigate the hydrologic effects of future climate and land-use changes in the Ohio River Basin. The land-use model is based on the Soil Conservation Service's curve-number method. It uses the curve number, an index of land use and soil type, to calculate runoff volume and depth. The ArcView programming language, Avenue, was used to integrate the two models into a geographic information system (GIS). An output of the water-balance model, daily precipitation values adjusted for potential evapotranspiration, served as one of the inputs into the land-use model. Two watersheds were used in the present study: one containing the city of Cincinnati on the main stem of the Ohio River, and one containing the city of Columbus on a tributary of the Ohio River. These cities represent two major metropolitan areas in the Ohio River Basin with different land uses experiencing different rates of population growth. The projected hypothetical land-use changes were based on linear extrapolations of current population data. Results of the analyses indicate that conversion from agricultural land use to low-density residential land use may decrease the amount of surface runoff. The land-use practices which generate the least amount of runoff are forest, low-density residential, and agriculture; whereas high-density residential and commercial land-use types produce the highest runoff. The hydrologic soil type present was also an important factor in determining the amount of runoff and non-point-source pollution. A runoff-depth matrix and total nitrogen matrix were created for Cincinnati and Columbus to describe possible land-use mitigation measures in response to global climate change. The differences in Cincinnati and Columbus were due to differences in geographic location, air temperature, and total runoff. The results of this study may be useful to planners and policy makers for defining the possible impacts of future global climate and land-use changes on water resources.     

The Environmental Performance Strategy Map: an integrated LCA approach to support the strategic decision-making process

Life Cycle Assessment (LCA) is a well-known tool for analyzing environmental impacts on a wide perspective with reference to a product system and the related environmental and economic impacts. The need for a novel approach that complements environmental and financial considerations is addressed in this study with the introduction of a new graphical representation: the Environmental Performance Strategy Map. This graphical map allows one to combine the main environmental indicators (footprints) with the additional dimension of cost. The paper defines the Sustainable Environmental Performance Indicator as a single measure for sustainability of a given option. Comparison of different options for strategic decision-making purposes can be enhanced and facilitated by the use of this indicator.