The Environmental sustainability of mining in Australia: key mega-trends and looming constraints

At first ‘sustainable mining’ could be perceived as a paradox—minerals are widely held to be finite resources with rising consumption causing pressure on known resources. The true sustainability of mineral resources, however, is a much more complex picture and involves exploration, technology, economics, social and environmental issues, and advancing scientific knowledge—predicting future sustainability is therefore not a simple task. This paper presents the results from a landmark study on historical trends in Australian mining, including ore milled, ore grades, open cut versus underground mining, overburden/waste rock and economic resources. When complete data sets are compiled for specific metals, particular issues stand out with respect to sustainability—technological breakthroughs (e.g. flotation, carbon-in-pulp), new discoveries (e.g. uranium or U), price changes (e.g. Au, boom/bust cycles), social issues (e.g. strikes), etc. All of these issues are of prime importance in moving towards a semi-quantitative sustainability model of mineral resources and the mining industry. For the future, critical issues will continue to be declining ore grades (also ore quality and impurities), increased waste rock and associated liabilities, known economic resources, potential breakthrough technologies, and broader environmental constraints (e.g. carbon costs, water). For this latter area, many companies now report annually on sustainability performance—facilitating analysis of environmental sustainability with respect to production performance. By linking these two commonly disparate aspects—mining production and environmental/sustainability data—it becomes possible to better understand environmental sustainability and predict future constraints such as water requirements, greenhouse emissions, energy and reagent inputs, and the like. This paper will therefore present a range of fundamental data and issues which help towards quantifying the resource and environmental sustainability of mining—with critical implications for the mining industry and society as a whole.     

Mining and sustainable development: considerations for minerals supply

Sustainable development involves meeting the needs of human societies while maintaining viable biological and physical Earth systems. The needs include minerals: metals, fuels, industrial and construction materials. There will continue to be considerable demand for virgin mineral resources, even if levels of recycling and efficiency of use are optimal, and rates of population growth and globalisation decrease significantly. This article aims to stimulate debate on strategic issues for minerals supply. While the world has considerable stocks of mineral resources overall, international considerations of the environmental and social aspects of sustainable development are beginning to result in limitations on where mining will be conducted and what types of deposits will be mined. Current and emerging trends favour large mines in parts of the world where mining can be conducted within acceptable limits of environmental and social impact. Finding new deposits that meet such criteria will be all the more challenging given a disturbing global decline in the rate of discovery of major economic resources over the last decade, and the decreasing land area available for exploration and mining.
To attract responsible exploration and mining, governments of mining nations will need to provide: regional-scale geo-scientific datasets as required to attract and guide future generations of exploration; resource access through multiple and sequential land use regimes, and frameworks for dealing with indigenous peoples' issues; and arrangements for consideration of mining proposals and regulation of mines that ensure responsible management of environmental and social issues.
The minerals industry will need to continue to pursue advances in technologies for exploration, mining, processing, waste management and rehabilitation, and in public reporting of environmental and social performance.     

Multi-Criteria Assessment of Tensions in Resource Use at Continental Scale: A Proof of Concept with Australian Rangelands

The purpose of this study was to help to inform policy development for the Australian rangelands, and provide a proof of concept for application of a multi-criteria analysis approach to assessment of competing resource use at continental scale. The study aimed to identify and locate key natural resource and agricultural production assets in the rangelands, define a number of measures of potentially threatening processes, and use a multi-criteria approach to identify areas where threatening processes, agricultural production problems, or valuable natural resources coincided. The analysis used 35 readily available, continental spatial data layers at 5-km pixel resolution ranked from 1 (low) to 5 (high) under three themed groupings: natural resource base, production base, and threatening processes. These measures were aggregated into composite indicators to define attributes such as environmental sensitivity and total grazing pressure. The composites were then compared in a two-way analysis to explore particular interactions between threatening processes such as pastoralism and mining, and the condition of production and natural resource assets. These interactions were defined as “tensions” for purposes of this analysis. Example “tensions” included the association of high grazing intensity with areas of high environmental sensitivity, indicating a risk of land degradation under adverse climatic conditions. A summary of patterns of tension was obtained by extracting area proportions of high-tension classes for selected Natural Heritage Trust Regions, which are a basis for Australian Government funding of improved environmental management. The study provides a basis for further examination of trade-offs in the use of natural assets, opportunities for improved productivity and sustainability, and social and economic implications.     

Modelling future copper ore grade decline based on a detailed assessment of copper resources and mining

The concept of “peak oil” has been explored and debated extensively within the literature. However there has been comparatively little research examining the concept of “peak minerals”, particularly in-depth analyses for individual metals. This paper presents scenarios for mined copper production based upon a detailed assessment of global copper resources and historic mine production. Scenarios for production from major copper deposit types and from individual countries or regions were developed using the Geologic Resources Supply-Demand Model (GeRS-DeMo). These scenarios were extended using cumulative grade-tonnage data, derived from our resource database, to produce estimates of potential rates of copper ore grade decline.The scenarios indicate that there are sufficient identified copper resources to grow mined copper production for at least the next twenty years. The future rate of ore grade decline may be less than has historically been the case, as mined grades are approaching the average resource grade and there is still significant copper endowment in high grade ore bodies. Despite increasing demand for copper as the developing world experiences economic growth, the economic and environmental impacts associated with increased production rates and declining ore grades (particularly those relating to energy consumption, water consumption and greenhouse gas emissions) will present barriers to the continued expansion of the industry. For these reasons peak mined copper production may well be realised during this century.     

The morality behind sustainability

The concepts of sustainable agriculture, organic agriculture, regenerative agriculture, and alternative agriculture are receiving increasing attention in the academic and popular literature on present trends and future directions of agriculture. Whatever the reasons for this interest, there nevertheless remain differences of opinion concerning what counts as a sustainable agriculture. One of the reasons for these differences is that the moral underpinnings of a policy of sustainability are not clear. By understanding the moral obligatoriness of sustainability, we can come to understand precisely what must be sustained, and by implication, how. This article discusses the arguments that can be advanced for sustaining anything and initially concludes that our obligations to future generations entail sustaining more than just sufficient food production or an adequate resource base. Indeed, a tradition of care and community must underlie whatever agricultural and resource strategies we are to develop under the rubric of sustainability. A consideration of the larger social and environmental system in which agriculture operates and the constraints this system places on agriculture forces us to recognize that sustainability has to do with larger institutional issues, including our ability to incorporate our common morality democratically into our institutions, practices, and technologies.     

Surface iron ore mining in eastern India and local level sustainability

Mining often brings certain irreversible changes to the surrounding environment. Different types of natural resources mostly surround the mines. Degradation of natural resources around the active mining zone may adversely affect the local economy. After cessation of mining operations local people may no longer be able to sustain their livelihood from the surrounding degraded natural resource; there are chances that the economy of the region will be shattered. The paper deals with this problem of local level sustainability of iron ore mining in eastern India. This problem is examined in the light of different theories of sustainability and national policies. By using household survey data, sustainability of iron ore mining in this region is tested. Substitution of depleting natural capital with other forms of capital can promote long-term sustainability of the local economy. This necessitates certain policy interventions to induce the mine operators to reinvest some part of their resource rent in the natural capital of the region.     

Long-term perspectives on world metal use—a system-dynamics model

In this paper, a system dynamics model is described, which simulates long-term trends in the production and consumption of metals (i.e. iron/steel and an aggregate of metals of medium abundance) in relation to impacts such as ore-grade decline, capital and energy requirements and waste flows. This metal model can be of assistance in exploring the issue of sustainability of metal resource use. Application of the model to historical trends shows it to be fairly capable of reproducing the long-term trends in the 1900–1990 period, among others on the basis of two intensity of use curves applied to 13 world regions. For future trends, a set of perspective-based long-term scenarios has been constructed that represent the major paradigms in resource use. These scenarios highlight some of the uncertain factors in the relation between economic growth, metal resource exploitation and use, and energy and environmental consequences. They also indicate that apparently similar metal flows in society may be the result of quite different and sometimes contrary assumptions on metal demand, production patterns and resource base characteristics. Such analyses contribute to a more open and transparent discussion on the issue at hand by adding quantitative explications to qualitative views.     

Ecometrics' stakeholder subjectivity: Values,issues, and effects

Stakeholder groups, defined according to their transcendent values, have different concepts of sustainability. Their prioritizations of individual, family, collective, and local and global environmental issues also differs. Given this, the metrics required for a given sustainable development path are subjective. Therefore, the questions of who should define ecometrics, their transparency, number, state of aggregation, standardization, and benchmarking are questions that require an enfranchised multi-stakeholder debate. At present, corporations have been asked to bear the burden of environmental reporting and eco-indicators have been established to account for material intensity, energy consumption and waste or toxic releases, among other factors. However, the links among these local-, product-, or service-based microecometrics and global states such as temperatures or atmospheric concentrations have yet to be established. The relationship of macroecometrics to individual definitions of sustainable development also has not been addressed. This article summarizes four plenary lectures given at ECOMETRICS '98 in Lausanne, Switzerland. The workshop involved forty participants from industry, academic and government organizations representing seven countries and three continents.     

Environmental and resource sustainability of Chinese cities: A review of issues,policies, practices and effects

This paper synthesizes the English literature on current issues, policies and practices, and their effects on environmental and resource sustainability in China's ongoing urbanization. Aspects of urban sustainability reviewed include air, water, solid waste, energy efficiency, transportation and land use. It shows that Chinese cities have been and probably will continue to be struggling with issues such as air pollution, scarcity of clean water, solid waste and greenhouse gas emissions. But there are many opportunities for improvement. It suggests shortages of existing policies and major gaps in knowledge and practice, which can be helpful to policy makers, planners and researchers in China and other developing countries.     

Useful indicators of urban sustainability: Some methodological issues

This paper considers methodological questions concerning indicators of sustainability, which have arisen in the course of an EPSRC-supported project investigating a systems approach to assessing the sustainability of cities. The project aimed: (a) to develop a methodology, the Reference Sustainability System (RSS), for representing the energy, resource and material flows, on which the environmental sustainability of cities depends; (b) to show how this methodology could contribute to a more systematic assessment of the potential of technological and resource management strategies to enhance urban sustainability. Systems models of the material or resource flows caused by the household demand for paper, energy, water and bottled water have been constructed. The project has highlighted the complexity of assessing the contributions of specific technologies and strategies to enhanced sustainability. Particular issues raised include the relative merits and problems of using externality valuation methods compared to physical indicators, the difficulties of aggregating environmental impacts, the question of where system boundaries should be drawn in a life cycle analysis, and the need to consider both distant and local impacts which arise from the end-use demands of urban populations. The paper explores these issues, through the use of modelling results from the case studies. Particular emphasis is placed on the communication of research results to policy makers, interested organisations and the public, drawing on recent experience with the dissemination of results from the project's first case study relating to waste-paper management options.     

Optimal production scale of open pit mining operations with uncertain metal supply and long-term stockpiles

An open pit mining operation consists of various stages, and the calculation of the production capacities of these stages depends upon the available supply of ore (mineralized material of economic value) and waste material. Cutoff grade is the criterion that specifies the amount of ore and waste. The material with grade equal to or higher than the cutoff grade is classified as ore. The material with grade less than the cutoff grade is considered waste. While this explains the link between cutoff grade theory and the calculation of production capacities, the majority of optimization models for finding production capacities not only disregards this relationship but also ignores expected variations and uncertainty in metal content or the available supply of ore and waste material.     

Exploration and discovery of Australia's copper,nickel, lead and zinc resources 1976–2005

Examination of copper, nickel, lead and zinc (base metals) exploration expenditure and discovery in Australia over the period 1976–2005 reveals some significant trends. Australia's base metal resource inventory grew substantially as a consequence of successful exploration over the period, both through addition of resources at known deposits and new discoveries, notably a small number of very large deposits that underpin the resource base. In 2005, Australia had the world's largest economic demonstrated resources (EDR) of nickel, lead and zinc, and the second largest EDR of copper. Growth in nickel resources has been especially strong owing to discovery of large laterite resources in the late 1990s. Resource life, in average terms based on current EDR and production, is approximately 30 years for lead and zinc, 40 years for nickel sulphide (120 years for all nickel EDR) and 50 years for copper. Despite this success, major increases in production over the period (copper, nickel and zinc output increasing 3–4 fold, lead output doubling) and a fall in discovery rates during much of the 1990s means that resource life for lead and zinc is lower and nickel sulphide comparable now to that in 1976; only the resource life of copper has grown substantially over the period. Current published ore reserves are sufficient for at least 15 years operations at current production levels, but only a small number of the largest deposits currently being mined are likely to still be in production in 20 years. However, several mines have substantial inferred resources that may allow production beyond current mine reserves and there is a substantial number of undeveloped deposits that may provide the foundation for extended or new mining operations. The discovery record is strongly cyclical with resource growth for all the base metals punctuated by the discovery of giant (world-class) deposits each decade: these underpin current and future production. Recent higher metal prices and renewed interest in base metals, especially nickel, has reversed a 10 year decline in base metal exploration attended by reduced rates of discovery and resulted in record expenditure, new nickel, copper and zinc discoveries, and increased resources at a number of existing deposits, notably the Olympic Dam copper–uranium–gold deposit. With the exception of the Prominent Hill copper–gold and West Musgrave nickel–copper deposits, most of the recent discoveries, especially zinc (-lead) deposits, are of small tonnage (some of high grade). Nevertheless, these new discoveries have helped stimulate further exploration and also highlight the potential for further discoveries in little-explored provinces, especially those under regolith and shallow sedimentary cover.     

Quantifying the impacts of primary metal resource use in life cycle assessment based on recent mining data

The quantification of impacts in the abiotic resource category in life cycle assessment is still controversial. However, this is a pertinent issue because of the growing dependence of our industrial society on these resources, particularly on metal resources. One of the important shortcomings of the existing assessment methods used today is that characterization factors are not based on actual mining practice data. In this paper, a new characterization factor derived from recent (1998–2010) and representative (more than 50% coverage of global primary metal production) mining data was established for nine metals: copper, zinc, lead, nickel, molybdenum, gold, silver, platinum and palladium. The quantification of this new characterization factor is based on the annual increase in mass of ore required per unit mass of metal in the ore. This quantification relies on the concept that the mining of resources is threatened not by lack of ores but by changing ore characteristics, e.g., the percentage of metal in the ore, mineral type and location. The characterization factors determined in this study ranged from below 0.1 kg ore kg⁻¹ y⁻¹ for zinc to more than 15,000 kg ore kg⁻¹ y⁻¹ for gold. These results indicate that in 1999, 370,000 kg of ore was required per kg of gold in the ore, whereas in 2008, 530,000 kg of ore was required per kg of gold in the ore (an increase of approximately 4% per annum). When comparing these results with traditional life cycle impact assessment methods, it was found that in all but one method gold, palladium and platinum have the highest characterization factors among the nine metals. In all methods based on ore grade changes lead and zinc are the metals with the lowest characterization factors. However, an important difference in the proposed method is that it assigns higher relative values to precious metals. This suggests that the supply of precious metals may be under more pressure than indicated by other methods, which in the framework of the proposed method implies greater efforts in mining and mineral processing. There is still scope for improvement of the proposed method if more data become readily available.     

Government and voluntary policymaking for sustainability in mining towns: A longitudinal analysis of Itabira,Brazil

The socio‐economic fabric of single‐company mining towns needs to be carefully considered by both Government and companies in sustainability policymaking. Policy design and effectiveness in such towns are significantly impacted by the city's economic dependence on a single company. This paper explores the perceived effectiveness of government and voluntary private sector mining policies for pursuing sustainability in the historic mining town of Itabira, Brazil over a period of 20 years. Itabira serves as a worthwhile case study because it allows for an in‐depth and longitudinal analysis that can reveal valuable lessons to policymakers of different sectors and jurisdictions located elsewhere. Based on extensive face‐to‐face interviews and literature reviews, study results indicate that changes to the state environmental licensing policies in the 1990s led to significant socio‐environmental improvements in the area. The globalization of the mining company also contributed to an increase in the quantity and quality of voluntary industry policies. Recent technological improvements in the beneficiation processes of the mining company promises to extend the life of the mine to 2050. Although there are significant incremental socio‐environmental policies and programmes, sustainability remains an elusive vision in Itabira, with no clear objectives or monitoring and accountability mechanisms. The paper concludes by recommending a more formal integrated policymaking framework.     

Innovation for sustainable development in artisanal mining: Advances in a cluster of opal mining in Brazil

The objective of this article is to understand how the promotion of clusters of small economic agents in the gem sector has brought some improvements in the economic, social and environmental conditions in the mining sector and activities related to it. The research provides policy and theoretical contributions to the field of gem production, as well as enhances understanding of the under researched opal production in Brazil. It argues that government funding and technical support dedicated to the development of mining clusters, i.e. working with small economic agents as a whole and not individually, could promote not only more economic development, but also effectively incorporate social and environmental issues, such as workers safety, water management and tailings recycling. The argument is based on an evaluation of environmental, economic, social and institutional aspects of the opal mining cluster in Pedro II municipality, Piauí state. The results suggest that some formalisation of existing practices and adequate policies have triggered innovation with some positive effects on the performance of artisanal mining. Nevertheless, there are indications that if decision-makers plan to make this cluster more sustainable, they will have to include other issues in the debate including developing substituting economic activities.     

A heuristic approach to stochastic cutoff grade optimization for open pit mining complexes with multiple processing streams

Cutoff grade specifies the available supply of metallic ore from an open pit mine to the multiple processing streams of an open pit mining complex. An optimal cutoff grade strategy maximizes the net present value (NPV) of an open pit mining operation subject to the mining, processing, and marketing/refining capacity constraints. Even though, the quantities of material flowing from the mine to the market are influenced by the expected variation in the available metal content or inherent uncertainty in the supply of ore, the majority of cutoff grade optimization models not only disregard this aspect and may lead to unrealistic cash flows, but also they are limited in application to an open pit mining operation with single processing facility. The model proposed herein determines the optimal cutoff grade policy based on a stochastic framework that accounts for uncertainty in supply of ore to the multiple ore processing streams. An application on a large-scale open pit mining operation develops a unique cutoff grade policy along with a portfolio of mining, processing, and marketing/refining rates. Owing to the geological uncertainty, the approach addresses risk by showing a difference of 14% between the minimum and maximum production rates, cash flows and NPV.     

Multiproduct mine output and the case of mining waste utilization

This article addresses the concepts of economies of scope and multiproduct production, subadditivity and transray convexity as it applies to the mining industry. The article goes on to expand these concepts to include the case of mining waste utilization. It discusses how the modification of mining wastes into a marketable product can develop a relationship across the cost functions of the modified mining waste and ore production and how this interrelationship affects the profit maximizing condition. It discusses four possible outcomes from mining waste modification and its development into marketable products on the profitability and production of ore by the firm. Finally, it discusses mining waste utilization effects on rehabilitation costs and the potential for a decrease in the adverse community effects due to mine closure.     

An uncertainty based multi-criteria ranking system for open pit mining cut-off grade strategy selection

Cut-off grade strategy (COGS) is a concept that directly influences the financial, technical, economical, and environmental issues in relation to the exploitation of a mineral resource. Despite the simple definition of cut-off grade, the COGS problem is one of the complex and complicated problems in the mine planning process. From the optimization point of view, the COGS with an objective of maximizing the present value of future cash flows is a non-linear and a non-convex problem that even in its deterministic form can be solved using approximate optimization methods. This optimization problem will also be more complex and complicated under uncertainty conditions. This paper proposes an uncertainty based multi-criteria ranking system to investigate the problem of COGS selection considering metal price and geological uncertainties. The proposed system aims at selection of the best COGS among technically feasible alternative COGSs under uncertainty circumstances. Our developed system is based on integrating metal price and geological uncertainties as well as operating flexibility to close the mine early. We incorporate this operating flexibility into the proposed system using a Monte Carlo based real options (RO) valuation model. For this purpose, in addition to the expected value, other risk criteria are considered to rank the alternatives. These risk criteria include abilities of strategies in producing extra profits, minimizing losses, and achieving the predefined goals of the production. In this study, the technically possible COGSs are generated using the Lane comprehensive algorithm. To demonstrate the effectiveness of the proposed system, we utilize data of an Iranian gold mine. Results show that the proposed system outperforms conventional methods in the sense that it shows significantly lower average mis-ranking than the other methods and also selects a strategy with a higher value. The sensitivity analysis of the proposed system relative to the gold price shows that the system is highly dependent on the parameters of the stochastic process used to model the evolution of the metal price. Therefore, special consideration should be given in estimating stochastic process parameters.     

The investment climate for gold mining

This analysis compares the gold mining industry investment climate in the USA to the investment climate in Australia. These two major gold producing nation's industries share many similarities; in both the USA and Australia, there is evidence of a maturing gold mining industry. Each country has experienced a dramatic increase in gold production and, more recently, greater mining of refractory ore and development of more underground operations. In the 1980s both nations experienced a pronounced rationalization trend that consolidated some gold producing operations and eliminated others. Each country commands a disproportionately large share of exploration expenditures. Land access, a major concern in the USA, has also become a critical issue in Australia as well. For all their similarities, however, the two countries have differences that are significant enough to influence mining company investment decisions. This paper explores those differences and how they may affect the future course of these nations' gold mining industries. Both effective government policy making and corporate strategic planning will occupy a major role in the future course of the two nations' gold mining industries .     

Labour challenges and mercury management at gold mills in Zimbabwe: Examining production processes and proposals for change

The use of mercury in small-scale gold mining has been a growing concern in many parts of Africa. However, although the negative effects of mercury pollution are increasingly reported, little has been written about how labour relationships and gold production challenges in mining communities affect mercury management practices. This article provides an integrative analysis of small-scale gold extraction processes, labour challenges, and mercury use at gold mills in Zimbabwe, focusing on a gold rush area in Mashonaland West Province. It examines practices employed by miners who have limited economic capacities to upgrade technologies, and how the complex relationships between miners, mill owners and government regulators affect environmental performance. The study draws attention to how poor environmental management practices relate to labour inequities, low gold recovery as well as the informal gold trade dynamics amid the country's economic crisis. Results of a United Nations-supported stakeholder consultation process are discussed, with proposals for improving labour conditions and reducing environmental risk. The article highlights why the government should develop and support local programs to assist miners, as well as the decisive roles mill owners could take in ensuring improved standards on their sites.