Mining Life Cycle Research Articles

A Holistic Approach in Re-Mining Old Tailings Deposits for the Supply of Critical-Metals: A Portuguese Case Study

Demand growth for metallic minerals has been faced with the need for new techniques and improving technologies for all mining life-cycle operations. Nowadays, the exploitation of old tailings and mine-waste facilities could be a solution to this demand, with economic and environmental advantages. The Panasqueira Mine has been operating for more than a century, extracting tungsten and tin ore. Its first processing plant, “Rio”, was located near the Zêrere river, where mineral-processing residues were deposited on the top hillside on the margin of this river in the Cabeço do Pião tailings dam. The lack of maintenance and monitoring of this enormous structure in the last twenty years represents a high risk to the environment and the population of the surrounding region. A field-sample campaign allowed the collection of data, and resulted from laboratory tests to use regression optimization. Re-mining the tailings by hydrometallurgical methods was considered to satisfy the two conditions of metal demand and environmental risk. The metal content in Cabeço do Pião was shown be enough for environmental restoration. The re-mining solution was studied, taking into account the technical, economic, social, and environmental aspects.

Environmental protection or subversion in mining? Planning challenges, perspectives and actors at the largest gold deposit in Europe

The gold ores in Roşia Montană have been intensely mined for the last two thousand years, as this mining district was one of the richest gold deposits in the Apuseni Mountains (the so-called Golden Quadrangle of Romania). Itis currently considered the largest gold deposit in Europe. Up until a few decades ago, gold mines had a relatively predictable path, which began with exploration and ended with abandonment. This has since changed, once the impact of abusive past or current exploitation methods and technologies has been deemed unacceptable by the state and the public. With its millennia-old history of mining, Roșia Montană raises the intriguing question of what does the future hold for different actors in a situation that is clearly unsustainable, but which may be continued through environmental rehabilitation, or even a larger mine. We address the question for this particular mine by drawing on a worldwide database of similar cases contained in the Environmental Justice Atlas (EJAtlas). We consider three scenarios, namely: 1) continued degradation with no intervention; 2) approval of large-scale mining, due to international arbitration; 3) environmental rehabilitation. These capture the most plausible future scenarios of the Roșia Montană case and, by relating them to the relevant transnational environmental justice context, we aim at assessing their implications for different actors and also the extent to which they are illustrative for the fate of other mines worldwide. Mine closure and the rehabilitation of the environment, regardless how distant they may seem at the beginning of the prospection and extraction stage, are imminent in the mine life cycle and a mandatory step of the environmental management process. We conclude by suggesting under which governance regimes each scenario is likely to unfold and what implications can be drawn for public policy.

Phylogenetic Estimation of Community Composition and Novel Eukaryotic Lineages in Base Mine Lake: An Oil Sands Tailings Reclamation Site in Northern Alberta.

Reclamation of anthropogenically impacted environments is a critical issue worldwide. In the oil sands extraction industry of Alberta, reclamation of mining-impacted areas, especially areas affected by tailings waste, is an important aspect of the mining life cycle. A reclamation technique currently under study is water-capping, where tailings are capped by water to create an end-pit lake (EPL). Base Mine Lake (BML) is the first full-scale end-pit lake in the Alberta oil sands region. In this study, we sequenced eukaryotic 18S rRNA genes recovered from 92 samples of Base Mine Lake water in a comprehensive sampling programme covering the ice-free period of 2015. The 565 operational taxonomic units (OTUs) generated revealed a dynamic and diverse community including abundant Microsporidia, Ciliata and Cercozoa, though 41% of OTUs were not classifiable below the phylum level by comparison to 18S rRNA databases. Phylogenetic analysis of five heterotrophic phyla (Cercozoa, Fungi, Ciliata, Amoebozoa and Excavata) revealed substantial novel diversity, with many clusters of OTUs that were more similar to each other than to any reference sequence. All of these groups are entirely or mostly heterotrophic, as a relatively small number of definitively photosynthetic clades were amplified from the BML samples.

Characterising the interface between large and small-scale mining

There are many scenarios that can develop when the large and small-scale mining sectors form an interface. This paper focuses on the complexities of large-scale and artisanal and small-scale mining (“LSM” and “ASM”) operating within a shared physical environment. The term “interface” is used to characterize the many points at which LSM and ASM physically intersect at the asset level, and the ways in which these interactions shape development options and outcomes for both sectors. In doing so, we use terminology associated with LSM. Terms such as “mine lifecycle”, “project approval” and “risk management” provide entry points into the analysis, and highlight the drivers of interactional outcomes left unexplained in the existing literature. We provide a base typology for researchers and other parties to engage the complex dynamics that define the LSM-ASM interface. Our objective is to show that by examining the interface through the prism of large-scale resource development, we can achieve greater clarity about the enabling and constraining factors for existing pro-ASM policy initiatives.

Environmental Impact of Mine Exploitation: An Early Predictive Methodology Based on Ore Mineralogy and Contaminant Speciation

Mining wastes containing sulfide minerals can generate contaminated waters as acid mine drainage (AMD) and contaminated neutral drainage (CND). This occurs when such minerals are exposed to oxygen and water. Nowadays, mineralogical work—when it is done—is independently and differentially done according to the needs of the exploration, geotechnics, metallurgy or environment department, at different stages in the mine development process. Moreover, environmental impact assessments (EIA) are realized late in the process and rarely contain pertinent mineralogical characterization on ores and wastes, depending on countries’ regulations. Contaminant-bearing minerals are often not detected at an early stage of the mine life cycle and environmental problems could occur during production or once the mine has come to the end of its productive life. This work puts forward a more reliable methodology, based on mineralogical characterization of the ore at the exploration stages, which, in turn, will be useful for each stage of the mining project and limit the unforeseen environmental or metallurgical issues. Three polymetallic sulfide ores and seven gold deposits from various origins around the world were studied. Crushed ore samples representing feed ore of advanced projects and of production mines were used to validate the methodology with realistic cases. The mineralogical methodology consisted in chemical assays and XRD, optical microscopy, SEM and EPMA were done. Five of the ores were also submitted to geochemical tests to compare mineralogical prediction results with their experimental leaching behavior. Major, minor, and trace minerals were identified, quantified, and the bearing minerals were examined for the polluting elements (and valuables). The main conclusion is that detailed mineralogical work can avert redundant work, save time and money, and allow detection of the problems at the beginning of the mine development phase, improving waste management and closure planning.

Towards circular economy in mining: Opportunities and bottlenecks for tailings valorization

Current management of mining waste is based on linear economy thinking. However, the use of mining waste as a raw material resource can be one solution to the limited metal supply. The objective of this study was to fill in the knowledge gaps of business opportunities, drivers, needs and barriers for tailings valorization, since the transformation towards a circular economy needs advancements in understanding these factors. Based on a workshop and theme interviews, the utilization of tailings in the mining industry is currently in its infancy, but there is clear raw material potential for the future. The handling of sidestreams at mine sites depends on mine lifecycle. The identified opportunities and drivers were categorized under the circular economy mindset, technological, environmental, institutional and economic drivers. The needs were new value chains, technology development, the decrease in the amount of waste, stability, taxation, and predictability of regulation. Challenges and bottlenecks were categorized under new value chains, technological, environmental, institutional, economic and knowledge bottlenecks. The identified needs and barriers need to be properly addressed to speed up the transformation towards the circular economy in the mining industry.

Mining Deformation Life Cycle in the Light of InSAR and Deformation Models

The Sentinel-1 constellation provides an effective new radar instrument with a short revisit time of six days for the monitoring of intensive mining surface deformations. Our goal is to investigate in detail and to bring new comprehension of the mine life cycle. The dynamics of mining, especially in the case of horizontally evolving longwall technology, exhibit rapid surface changes. We use the classical approach of differential radar interferometry (DInSAR) with short temporal baselines (six days), which results in deformation maps with a low decorrelation between the satellite images. For the same time intervals, we compare the radar results with prediction models based on the Knothe–Budryk theory for mining subsidence. The validation of the results with ground levelling measurements reveals a high level of resemblance of the DInSAR subsidence maps (−0.04 m bias with respect to the levelling). On the other hand, aside from the explicable exaggeration, the location of the subsidence trough needs improvement in the forecasted deformations (0.2 km shift in location, a deformation velocity four times higher than in DInSAR). In addition, a time lag between DInSAR (compatible with extraction) and prediction is revealed. The model improvement can be achieved by including the DInSAR results in the elaboration of the model parameters.

Innovation and technology for sustainable mining activity: A worldwide research assessment

The analysis of innovations and technologies aimed at improving the sustainability of mining activity has become important in recent decades. The main objective of this article is to evaluate the dynamics of this line of research worldwide between 1998 and 2017. A bibliometric analysis and a systematic review of a sample of 2,562 articles was developed along with an analytical framework based on the mine life cycle and the three areas of sustainability (economic, social and environmental). The results show that sustainability research has grown at a much higher rate than that of mining and minerals research. The three journals that have published the most articles on this line of research are Journal of Cleaner Production, Environmental Science and Technology, and Gornyi Zhurnal, and the three countries with the highest number of published articles are the USA, China, and Germany. Some 60.9%, 30.9%, and 8.2% of the analysed mining innovations impact environmental, economic, and social sustainability, respectively, and some 7.1% affect the exploration phase, 84.8% the exploitation phase, and 8.1% the closure phase. The analysis of issues related to environmental sustainability becomes more relevant as the exploration phase moves on to exploitation and closure. The primary challenges and future lines of research are in reducing energy use and increasing the use of renewable sources, analysing the social sustainability of current mining activities, and achieving clean production in the development of new mining activity environments (ice-covered areas and the ocean floor). This work provides new perspectives on the analysis and integral assessment of innovations and technologies aimed at making mining activity more sustainable, particularly where the contributions to the environmental, economic, and social fields are valued.

Environmental impacts of the life cycle of alluvial gold mining in the Peruvian Amazon rainforest

Alluvial gold mining activities in the Peruvian Amazon rainforest are responsible for mercury emissions and deforestation. To understand related environmental impacts, specifically toxicity and climate change, this study uses Life Cycle Assessment methodology. Four predominant extraction systems were selected and modelled and three scenarios that reflect currently available gold recovery systems were modelled: amalgamation, amalgamation with mercury recovery through retort system and gravimetric tables. The USEtox and IPCC life cycle impact assessment methods were used to assess the environmental impacts in term of human toxicity, freshwater ecotoxicity and climate change.Results show that for all systems, human toxicity values are governed by mercury emissions in gold recovery activities (ca. 80%). However, the use of retort significantly lowers these impacts (ca. 90%). Machines and diesel use for ore extraction and freighting activities drive freshwater ecotoxicity. Moreover, deforestation has a major contribution on the environmental impacts related to climate change. However, these impacts are dependent on the type of extraction system. Although human toxicity, freshwater ecotoxicity and climate change are frequently studied separately, a direct relationship between them has been identified in this system. Finally, beyond the environmental burdens related to alluvial gold mining, there are impacts affecting the social, cultural, and economic dimensions that will need to be analyzed to ensure a comprehensive understanding of the system.

A Shaft Pillar Mining Subsidence Calculation Using Both Probability Integral Method and Numerical Simulation

In order to prolong the life cycle of the coal mine, Jinggezhuang (‘JGZ’) coal mine decided to excavate the shaft pillar. The first panel 0091 was designed near the pillar boundary as an experiment in shaft pillar mining. Both probability integral method (PIM) and FLAC^3D were used to evaluate the influence on the shaft safety. PIM parameters were obtained from previous surface subsidence station. The rock property is based on the lab mechanical test. A simulated FLAC^3D model containing shafts and a panel was built based on stratigraphic information. Surface subsidence results of PIM show that the 0091-panel excavation has no influence on the shafts. The simulated results show that the subsidence of the main shaft and air shaft is small and can be ignored, but it could cause the auxiliary shaft 220 mm horizontal displacement. So, the stress and displacement of the underground part of shaft were analyzed, it shows that the stress changes, subsidence and displacement are mainly located at the top part of the shafts. According to the stress and movement of the simulated shafts, 0091 was decided to be excavated and a surface monitor line was built and measured. In comparison of PIM, FLAC^3D, and measured data, the PIM results fit the surface subsidence better. And the FLAC^3D results have smaller maximum subsidence and greater influence area than measured. But FLAC^3D can provide more details such as displacement, subsidence, stress and strain of both surface and underground. So, for a planned mining excavation, both methods should be used especially for the evaluation of deformation of underground constructions. In the future, with the development of the rock numerical computation technology, the numerical simulation method will be recommended first. The research shows compare of two methods of the coal mine subsidence calculation and provides a solution method for shaft pillar mining.

Using risk assessments to address corruption in mining

Transparent and accountable mining can contribute to sustainable development. This begins with corruption-free approvalsthe very first link in the mining value chain when decisions are made about whether, where, and under what circumstances to permit mining, including who is awarded licences or contracts. This viewpoint introduces the Mining Awards Corruption Risk Assessment Tool developed by the global civil society anti-corruption coalition, Transparency International. Corruption in mining approvals can result in environmentally unsound and socially destructive mining projects being approved, rights to a country's mineral wealth being granted to unqualified or unethical operators, and politicians or government officials taking advantage of their position to profit from their interests in the sector. Corruption at the start of the mine lifecycle compromises the rest of the processimpairing how operations are monitored and regulated, undermining the collection of taxes and royalties and damaging the mining industry's social licence to operate. Identifying, assessing and then managing the risks of corruption are integral to effective anti-corruption strategies.

Green Mining – A Holistic Concept for Sustainable and Acceptable Mineral Production

Mining has become increasingly difficult for societal and environmental reasons all over the world. There is increasing competition with other land uses, and water and energy are scarce in many important mining regions. People are not ready to radically reduce the use of mineral-based products, but increasingly oppose mining. The industry faces major challenges to improve its performance and image. The Green Mining concept (GM) was developed as a major tool to make Finland the forerunner in sustainable mining. It promotes material, water and energy efficiency to reduce the environmental footprint of mineral-based product life cycles. GM allows the recovery of all useful minerals and minimises mining waste. GM aims to ensure the availability of mineral resources for future generations, which requires long-term investment in exploration supported by geoscientific mapping, mineral systems research and the development of exploration techniques. An important goal of GM is to minimise adverse environmental and social impacts in all stages of the operations, and to maximise local benefits. GM helps to organise the operations in such a way that they are safe and meaningful to employees, and harmless for local residents and the environment. After mine closure, GM helps to restore the mining areas to make them safe and preferably to allow other types of land use. The broad-based participation of local residents and other stakeholders is crucial throughout the mining life cycle, from early exploration to mine closure. Societies, governments and investors will not tolerate unsustainable mining companies in the future. The mining industry has to solve increasing social, ecological and technical problems of the future by applying holistic concepts, such as the Green Mining concept, to earn the social license to operate.

Educational Data Mining Life Cycle Model for Student Mental Healthcare and Education in Malaysia and India

Educational Data Mining Life Cycle Model for Student Mental Healthcare and Education in Malaysia and India

The Role of the Mining Industry in a Circular Economy: A Framework for Resource Management at the Mine Site Level

SummaryThe circular economy (CE) concept advocates drastically reduced primary resource extraction in favor of secondary material flowing through internal loops. However, it is unreasonable to think that society will not need any resources, for example, metals, from mining activities in the short, medium, or longer term. This article explores the role of the mining industry in transitioning to the CE and shows that mines can make significant progress if they apply the CE principles at the mine site level. Circular flows within the economy aim at keeping resources in use for as long as possible and limit final waste disposal. Likewise, operating mines for as long as minerals can be extracted at acceptable environmental costs, thus minimizing the loss of a nonrenewable resource, can be viewed as a contribution of the mining industry to CE objectives. To test this idea, we propose a framework where the conservation of nonrenewable resources is a core concern. The first part establishes a set of material flow indicators relevant to a mine project. The second part considers the entire mine's life cycle, in particular, the consequences of interruptions in activities on material losses. The framework is then illustrated by a case study of the Mount Morgan mine in Australia, where three distinct extractive strategies were applied throughout its history. The results from applying the framework show that proactive and preventive management of mining waste provides significant environmental benefits and generates value from mine waste. These outcomes illustrate that the concept of the CE can be applied in a practical manner to a mining operation.

Corporate social responsibility in resource companies – Opportunities for developing positive benefits and lasting legacies

A key aspiration for Corporate Social Responsibility (CSR) in the resource sector is to leave behind a lasting and positive legacy for local and regional communities, which is referred to here as Enduring Community Value (ECV). This paper examines the capacity of resource companies to create ECV for local communities within three jurisdictions in Australia drawing on perspectives from resource company employees and key stakeholders including individuals and groups in local communities.The capacity to implement ECV was tracked through the planning, governance, implementation and evaluation phases of CSR for companies of different sizes, stage of mining life-cycle and degree of remoteness of mining operations.ECV was found to be a critical value of CSR for resource company employees and stakeholders, providing a common ground for engagement and cooperation. Company employees, also saw ECV as a necessary tool to help navigate the complexities of CSR within a local community context.Personal moral and ethical values of resource employees and stakeholders, including motivations to improve local community outcomes and to achieve sustainability drove the adoption of ECV. This was supported to varying degrees by resource companies’ culture and goals, organisational values of stakeholder organisations, regulatory and legislative frameworks, guidelines and standards.Through the application of Giddens’ structuration theory it was identified that there was a high reliance on human agency to drive outcomes, with a lack of consistent institutional structures and relevant processes being in place. This meant that planning for ECV often occurred late in the mine life-cycle, reducing the potential benefits. Further institutional support, such as through robust planning tools, guidelines and standards and resourced stakeholder forums where lessons, experiences and assessments are shared, could help drive outcomes more clearly toward ECV. The implications of models for CSR and sustainable development perspectives are also presented.

Setting rehabilitation priorities for abandoned mines of similar characteristics according to their visual impact: The case of Milos Island, Greece

Abstract Mine rehabilitation is nowadays an essential part of the mine life-cycle. Nevertheless, due to the inadequate legislative framework and the lack of appropriate financial instruments in the past, abandoned mined land is present in almost all regions with a mining history. Especially in times of fiscal and financial belt tightening, where direct funding is almost impossible, the restoration of abandoned mines becomes a difficult task and, consequently, prioritization of the restoration projects is necessitated. So far, several models have been developed for that purpose. The existing models, however, usually underestimate that, especially for non-reclaimed mines located close to populated areas, landscape degradation generated by surface mining is a critical factor. To this end, this paper presents, through an illustrative example, a new approach providing the means for prioritizing mine restoration projects based on the visibility of surface mines with regard to the neighboring areas of interest. The proposed approach can be utilized as an additional module in existing prioritization models, or it can be used standalone when considering a group of surface mines where what distinguishes them from each other is primarily the disturbance of the landscape.

Concentrator utilisation under geological uncertainty

Mineral concentrators are designed from preliminary geological data, and are therefore subject to geological uncertainty. This uncertainty has a demonstrable impact on the mining lifecycle, and has motivated stochastic strategic mine planning algorithms. The current paper describes how these algorithms may be extended to consider mineral processing operations in conjunction with open-pit mining operations. In particular, the paper describes an effective way to incorporate variable concentrator feed grade into these algorithms, which is the first step toward more elaborate representations of mineral concentrators. The resulting framework will be able to connect geological data to alternate configurations of the downstream resources, hence comparing the benefit of each configuration, and the corresponding capital investments. Sample computations are presented, comparing the net present value and utilisation for several different mineral processing capacities.

A Life Cycle Assessment study of iron ore mining

This paper assessed the cradle-to-gate life cycle of an iron ore mining. The study was based on production data from an open pit mine located in the Iron Quadrangle/Brazil. The functional unit was defined as “one tonne of iron ore concentrate produced” and the data used were collected directly from the company's production reports covering the time of one year. The evaluation included the classification and characterization of life cycle impacts, not including normalization and weighting as well as sensitivity analysis of results. The evaluation of impacts used SimaPro-7, Ecoinvent 2.0, Eco indicator'99 and IPCC 2007. The results indicated that the use of grinding media in the processes is the main source of environmental impacts in the iron ore production chain, highlighting its contribution to life cycle impacts on human health and quality of ecosystems. Ore transportation by conveyor belts powered by electricity was more efficient in relation to the generation of impacts on the abiotic resources depletion and on climate changes than ore transportation by diesel trucks because the electricity generation matrix in Brazil has significant participation from hydroelectric plants.

Mine Lifecycle Planning and Enduring Value for Remote communities

Mine lifecycle planning is critical to developing enduring value from mining for remote communities. The history of mining is replete with examples of communities being unsustainable post mine closure. The concept of enduring value involves ensuring that a sustainable community will remain following the closure of an associated mine. Since 2003, awareness has increased amongst the International and Australian peak mining bodies for the need to plan for enduring community value. This increased awareness has developed alongside the requirement for mining companies to operate in a socially responsible manner by maintaining a social license to operate. This paper thematically reviews the literature relevant to mine life cycle planning, enduring value, the socio-economic impacts of mining, and mine closure. Conditions required for a community to gain enduring value from mining include: ‘normalisation’ rather than being a ‘closed’ town; the existence of government support and funding; and realised economic diversification opportunities. It is imperative that these conditions are given due consideration 1) in the initial stages of mine and town planning and 2) throughout the life of the mine through ongoing monitoring and community engagement. However, we acknowledge the shortcomings in assuming planning is a panacea and suggest areas for further testing.

Mining and Processing Kaolin

Kaolin is used in many consumer products and as a functional additive and process enabler in manufacturing. It is typically extracted from open-pit mines that range from small to very large scale (tens to hundreds of thousands of dry metric tons produced per year). Ore processing consists of removing impurities, engineering particle size and shape, and enhancing certain properties through thermal and chemical treatment. In addition to the technical aspects of mining and processing, the social, environmental, and economic impacts of kaolin production are managed at each stage of the mining life cycle. Discussed herein are aspects of the history of kaolin mining, the classification of kaolin mines, the processing of kaolin, and the life cycle of mining.