Mine Closure Research Articles

Comparative capacity of global mining regions to transition to a post-mining future

This paper focuses on the ability of regions where mining is concentrated to adapt to closure given the regional assets and the complexities of their association with declining production of various commodities. We propose a conceptual framework to examine the relative capacity of global regions to transition and prosper post-mining by analysing contextual factors and characterising the mining footprint in the regions. Public sources of geo-locatable data are used to define and locate mining regions in transition and to assess the interacting mining and contextual factors that enable or constrain their capacity to transition. The data-driven examination illuminates the comparative capacity of global regions confronting the challenge of mine closure. It engages with themes from regional studies, mine closure and transition studies to consider multidimensional aspects of regional transition.

Are mining companies mature for mine closure? An approach for evaluating preparedness

Evaluating how well a mining company is prepared to close an operating mine can help in managing the risks of not achieving closure goals and intended future site conditions. Considering international best practices recommendations, we developed and tested a procedure to evaluate, during the operational phase, the preparedness of companies to close a mine. Based on the principles of physical stability, chemical stability, socioeconomic transition, and post-mining land use, a weighted checklist containing 69 best practice statements was tested in three operating metal mines in Northeastern Brazil. The best practice statements and their respective weights were submitted to a 12-member expert group. The practices are organized in four assessment areas: (i) mine closure documents, (ii) physical and chemical stability, (iii) costs and financial provisioning, and (iv) community engagement and social transition. In applying the tool, evidence is collected by document review, interviews and site inspections, and evaluated using professional judgement to determine a level of achievement for each group of practices. A preparedness index is then calculated and a preparedness level is obtained. All field-tested mines ranked high for cost and financial provisioning, possibly reflecting they are publicly-owned companies, but ranked in the medium range for the three other assessment areas, indicating a risk of negative legacy. Their preparedness for closure should be a matter of concern for investors, regulators and communities.

Restoration of Forest and Associated Ecosystem Services of Backfilled Open Cast Coal Mines at Dhanbad, Jharkhand, India

Backfilled open cast coal mines are subjected to reclamation and restoration as per the mining and mine closure policies of India. The present paper discusses a case study on restoration of 15 acres land of backfilled open cast mine in the Bharat Coking Company Limited (BCCL) located at Barora, Dhanbad district, India. Through this study an attempt has been made to quantify return of ecosystem services in terms of growth rate and survival rate of native species planted, nutrient replenishment, biodiversity conservation with insect diversity as an indicator. The paper briefs the stepwise methodology used for ecological restoration and results on early success indicators of successful reclamation.

Major trends shaping development of coal industry in the world and in Russia under conditions of low-carbon energy economy: Major trends. Part I. Coal sector development ratio and rates under the influence of major coal market countries

The Paris climate agreement and the restrictions introduced in connection with them boosted the decarbonization efforts and the global energy transition to renewable energy sources and hydrogen. For this reason, many countries have closed their coal-fired thermal power plants, switched to green energy sources and approved the concept of low-carbon development in the period up to 2050 (2060). In this regard, the domestic coal industry faced the risks of not only an accelerated reduction in coal production and exports, but also the risk of a possible complete closure of coal mines. In 2020, coal production in the world decreased by 4.9%, to 7.4 billion tons compared to the previous year. Russia remained the world’s 6th coal producer with 401.6 million tons of coal produced, including 312.9 million tons of power-generating coal. Russia’s share in the global coal production in 2020 was 5.5%. In connection with the introduction of cross-border carbon regulation, the burden on the Russian coal producers may reach significant proportions. Russia believes the EU’s new crossborder carbon tax is contrary to WTO rules in terms of trying to equalize products made in the EU with minimal CO2 emissions with products from other countries that use technologies with high CO2 emissions. However, many COP26 participants stressed that trans-carbon regulation could become the norm in the coming years and have a significant impact on hydrocarbon markets and trade flows. The analysis of these major factors and the current ratio and rates in production of power-generating coal makes the framework for the coal production prediction under conditions of low-carbon energy economy.

Inorganic arsenic contamination and the health of children living near an inactive mining site: northern Thailand.

Arsenic toxicity is a global health problem affecting millions of people. Contamination is caused by arsenic from natural geological sources leaching into aquifers, contaminating drinking water, and may also be caused by mining and other industrial processes. Acute arsenic poisoning is associated with nausea, vomiting, abdominal pain, and severe diarrhea. Chronic arsenic toxicity results in multisystemic diseases leading to central nervous system (CNS) impairments such as cognitive or intellectual deficits in children. Over the past ten years, arsenic contamination has been reported in northern Thailand. The Ministry of Public Health; Thailand, Forensic Science Institute Thammasat University, and the Research Center to Promote Safety and Prevent Injuries in Children at the Ramathibodi Hospital compiled a report on the health impact of the population within a 10 kilometer radius around a mine tailing in the Phichit, Phitsanulok, and Phetchabun Provinces of Thailand. It showed that more than 30 % of children (aged 8-13 years) had higher than normal arsenic contamination levels based on the Agency for Toxic Substances and Disease Registry (ATSDR). After the publication of that report, the mine was temporarily closed in 2016. Based on this data, this research aimed to follow arsenic contamination after the mining operation had stopped operation for three years. The study showed that 4.5 % of school aged children had levels of inorganic arsenic in their urine, higher than the normal range (ATSDR), showing clearly that inorganic arsenic contamination is still above the normal range in children living near an inactive mining site. Therefore, monitoring heavy metal contamination in Thailand and the health effects on vulnerable children who live near mines during regular operation or after being temporarily suspended can prevent and mitigate possible health impacts.

A Quantitative Sustainability Assessment for Mine Closure and Repurposing Alternatives in Colorado, USA

Responsible mine closure and repurposing are key to contributing to sustainable development by ensuring successful environmental rehabilitation and reducing socioeconomic risks. However, mine closure has primarily focused on remediation and rehabilitation of mined lands with limited consideration of stakeholder perspectives and the broader social, economic, and cultural impacts of closure. In this paper, we use stakeholder input to evaluate and compare three different repurposing alternatives for the tailings dam area of a mine in the state of Colorado, USA, which is expected to close in the next twenty years. By using multi-attribute utility theory (MAUT), we determine which alternative better reflects stakeholder preferences and results in the most economically, environmentally, and socially sustainable outcome. Our results show that although stakeholder groups have different ideas about what constitutes sustainable development in the context of mine closure and repurposing, it is possible to identify to what extent different scenarios can address these perspectives. We argue that integrating stakeholder views into mine closure design and repurposing can lead to more responsible and sustainable mine closure that is unique to a particular setting and stakeholder needs, and we provide a methodology that mining companies may use to understand stakeholder priorities and preferences.

Socio-Economic Resilience of Poland’s Lignite Regions

The article is seeking to analyse the coal transition in three Polish lignite regions as part of the scientific discussion on a just transition, which is a big challenge, especially in the regions and countries dependent on their own coal deposits as the main source of energy. Polish lignite mines are now entering the phase-out of coal, which results from implementing the assumptions of the Green Deal and the Paris climate agreement. The article answers the following question: what is the socio-economic resilience of coal regions in the context of the projected closure of mines in the coming years? The empirical analyses are based on secondary statistical data. The analysis and comparison of basic statistical data, i.e., the level of employment and lignite extraction in three lignite regions in the period from the end of the Second World War to 2017, allowed the authors to determine the phases of the adaptive cycle in which the individual regions are. In the second part of the study, the indicator evaluation method was used in order to calculate the Socio-Economic Resilience Index for individual areas (poviats) included in the coal regions, which made it possible to assess the current resilience and its intra-regional differentiation. The obtained results, which indicate that the regions under analysis are in different phases of the adaptive cycle and reveal their territorial heterogeneity, allow us to assume that the possibilities of a just energy transition of regions depend on the diversity of local conditions and resources, emphasising at the same time the territorial dimension of the issue of the energy transition.

Groundwater-level recovery following closure of open-pit mines

Open-pit mining has increased substantially over the past two decades. Many currently operating open-pit mines are facing the end of mine-life over the next few decades and, increasingly, focus is shifting towards mine-closure planning that provides evidence on available closure options under the given geological, hydro(geo)logical and climatic conditions. This study uses synthetic groundwater modelling to build basic process understanding of closure options and how these will determine the formation of pit lakes. This governs the long-term pit lake water quality and how postmining landscapes may be utilised. Simulations show that the recovery time of postmining groundwater levels increases with decreasing aquifer transmissivity. Final postmining water tables are predominantly controlled by the implemented mine closure options and climatic conditions. The most important decision is, thereby, whether to backfill the pit to above the water table or allow a pit lake to develop. Under moderately transmissive aquifer settings, backfilling of pits leads to rapidly rising groundwater levels within the first decade after mining, with water-table recoveries of above 70%. If mine voids remain unfilled, evaporation from the pit lake surface becomes a governing factor in determining whether the unfilled mine pit becomes a terminal sink for groundwater. Lake levels may remain subdued by several 10s of metres in arid to semiarid climates. If surplus surface water can be diverted into open pits, rapid filling can accelerate groundwater recovery of open pits in regions of low permeability. This is a less successful management option in transmissive aquifers.

Assessing the environmental performance of a novel coal mine brine treatment technique: A case in Poland

Although the energy transition results in decreased use of coal for power production, hard coal extraction will continue due to its importance in steel production and coal mine wastewater will continue generating after mines closure. The coal mining sector produces wastewater which results in environmental burdens and often contains valuable materials that can be treated to eliminate effluent discharge and recover contained materials. The aim of this study is to determine whether the implementation of a novel wastewater treatment technique in an existing coal wastewater treatment plant (WWTP) can improve both environmental performance and resource recovery potential. Our study assesses for the first time the environmental performance of the WWTP of Dębieńsko at the Upper Silesian Coal Basin, in Poland because coal mine effluents need to be treated to eliminate current environmental impacts on surface water bodies (rivers). The existing wastewater treatment system comprises reverse osmosis, evaporation and crystallization technologies. In the case of the novel ZERO BRINE technique, lab performance data is scaled-up and used for nanofiltration, reverse osmosis, electrodialysis and crystallization technologies. The environmental impacts analysis is performed with life cycle assessment (LCA) by considering mid-point impact categories (climate change, terrestrial acidification and fossil resource scarcity) and end-point damages (human health, ecosystems and resources). The functional unit is 1 m3 of coal mine wastewater input and a scenario is developed where the plant functionality concerns salt production. Results show that the implementation of the ZERO BRINE technique can improve the environmental performance of the WWTP for all considered impact categories due to a reduction in electricity consumption by 13% in the entire plant. Climate change, acidification, fossil resources scarcity, human health, ecosystems, and resources were improved by 16%, 13%, 12%, 25%, 21% and 13%, respectively. A sensitivity analysis is performed on the electricity consumption of electrodialysis which shows an additional improvement by 7% on all impacts. The ZERO BRINE technique produces both water and different types of salts. In this case, the multi-functionality of the system is addressed through substitution, while sensitivity analyses are carried out using mass and economic allocation methods.

Investigation of the Attenuation and Release of Cu2+ Ions by Polymer-Treated Tailings

This study investigated the attenuation and release behaviour of copper ions using a standard kaolin-silt slurry as the synthetic tailings in a high solids/high salinity application before and after inline flocculation. A homogenous, synthetic tailings slurry was prepared in a 0.6 M NaCl solution and treated in a low-shear mixer by adding Magnafloc® 336 flocculant. Following the evaluation of morphological properties of both the untreated (UT) and polymer-treated tailings (PT), identical equilibrium tests were performed via the bottle-point method constant concentration technique. The maximum copper ions uptake capacity of polymer-treated tailings was 25% more than the untreated slurry at the equilibrium state in a chemisorption process in which the ions had the capability of binding onto one location on the sorbent, which could be influencing other binding sites on the same sorbent. Polymer treatment resulted in a highly porous structure that exhibited an increased capacity to adsorb and retain copper ions compared to the UT materials. This behaviour indicates the strong binding between the copper ions and active site of the treated tailings particles with greater capability of this material for preserving heavy metal ions within their structure across a wide pH range (2–10) compared to the UT materials. The results advance the fundamental understanding of how inline flocculation can considerably improve the sorption capacity of high solids/high salinity tailings favouring potential long-term rehabilitation purposes at mine closure and the role of sorption and desorption of heavy metal ions’ behaviour play to achieve this goal.

Coal demand, market forces, and U.S. coal mine closures

AbstractEconomic transitions have the potential to displace workers and cause social unrest. Coal mine closures and the resulting employment losses in rural areas have become salient issues. Using data on coal mine and power plant operation, we model closure as a function of expected profits, which allows us to compare the effects on mine closure of specific demand and supply shocks to expected mine profits. Increasing costs of production have had a large impact on closures, but lower natural gas prices and lower electricity demand have played more recently important roles.

Sustainable Development in Mining Communities: The Case of South Africa's West Wits Goldfield

There is a significant role for the mining and minerals industry to play in achieving the Sustainable Development Goals (SDGs) at a global level, through supplying the raw materials needed for technological progress, human development and cleaner economic growth, and at a local level, through socio-economic development and support, environmental protection, and good governance. While mining companies support the SDGs at the corporate level, there is a lack of evidence to show whether they are being implemented at the mine site level. There is also a lack of clarity on who the mine host communities are and what happens to the SDGs commitments after mine closure. The aim of this study was to identify all the host communities in the West Wits goldfield in South Africa and measure a comprehensive set of local SDG indicators, to explore the local variations that are hidden at national and municipal level, and the implications for communities achieving the SDGs in the context of mine closure. The West Wits is home to over 300,000 people living in 47 diverse communities—towns, mine villages, townships, informal settlements, industrial areas and rural areas. While 23 local SDG indicators were selected, only 13 indicators across 8 SDGs could be measured using census data. The findings show significant inequality between communities and deprivation in many communities, particularly the informal settlements. There are low levels of education, internet access and employment across the communities, indicating high vulnerability to mine closure. Without major intervention the SDGs will not be met by 2030 and thousands of people in these communities will be left behind. This is even more concerning given the majority of mines are expected to close in the next 10–20 years and the local economy in the West Wits is largely reliant on mining. Achieving the SDGs will require collaboration between multiple mining companies, local government authorities, civil society and communities, and significant urgent interventions on education and skills development, internet access and employment creation beyond the mining industry.

Selection of Open-Pit Mining and Technical System’s Sustainable Development Strategies Based on MCDM

Mining of the extensive, steeply dipping ore deposit takes several decades. An open-pit mining method is more often used in the early years of such a mining enterprise (ME). The management of the enterprise is faced with the problem of changing the mining method as the depth of the quarry increases. Untimely solution of this issue or the choice of the wrong strategy for the development of ME leads to a decrease in profitability, and the emergence of environmental and social difficulties. We studied the functioning of one hundred and seven MEs from different countries and substantiated four main sustainable development strategies for ME and its main system—the open-pit mining and technical system (MTS): adjustment of the current stage of mining indicators, transition to a new stage of mining, transition to a combined open–underground mining, and mine closure. The result of our research is an original methodology for selecting a strategy for MTS sustainable development. Our methodology is based on a new system of parameters and indicators for evaluating the sustainability of the opening-up of an opencast system (OOS). This assessment system includes twenty-three indicators that characterize the technical, technological, economic, social, and environmental factors of sustainable development. We propose to select a strategy for MTS sustainable development using combined fuzzy AHP-MARCOS multicriteria decision method (MCDM). The result of our case study for the Malyi Kuibas ore deposit was the choice of a mine closure strategy. The reliability of the obtained result is confirmed by a multilateral sensitivity assessment using nine other known MCDMs, while changing the criteria weights and composition of strategies. The results of the study prove the need for a timely decision to change the MTS development strategy as the depth of production increases. In addition, we have shown the effectiveness of the selection methodology based on the multicriteria assessment of the OOS sustainability.

De socioloog Harry Hoefnagels SJ (1922-1990). Een kritische Limburger in vakbondszaken

In the 1960s and 1970s, sociologist and Jesuit Harry Hoefnagels, born in de mining town of Kerkrade, played a prominent role in debates on trade union renewal, developments in the Catholic Church, and in society in general. This article focusses on his ideas about industrial relations. Influenced by developments in the French Christian trade union movement (CFTC, later CFTD) in the early 1960s, Hoefnagels was very critical of the passive and conciliatory attitude of both the catholic and social democratic trade unions in the Netherlands. He was a pioneer in the movement towards the merger of the catholic Nederlands Katholiek Vakverbond (NKV) and the socialist Nederlands Verbond van Vakverenigingen (NVV) into Federatie Nederlandse Vakbeweging (FNV) in 1976. In Limburg, he played a prominent role in protests against the social consequences of mine closure in the late 1960. Research on his opinions and public performances is relevant in the context of societal change in the Netherlands in the 1960s and 1970s.

Social License for Closure—A Participatory Approach to the Management of the Mine Closure Process

The European Union’s climate policy and the assumptions of the European Green Deal require Poland to take decisive transition efforts. The achievement of climate neutrality is a challenge due to the special role of coal in the Polish economy. Closing mines and abandoning coal is the greatest challenge for local communities in mining regions. This article presents the example of Wałbrzych, a Polish post-mining town, which has been experiencing the accumulation of negative consequences of inadequately planned liquidation since the 1990s. The current activities of mining companies in the face of abandoning coal were also analyzed. The gaps identified in the literature indicate the need to define a new method of managing the liquidation processes, based on the consideration of key risks resulting from decommissioning, to minimize the social costs in the first place. In this regard, it is helpful to diagnose the social concerns of the stakeholders. The social aspects of mine closures remain a challenge and finding effective ways to deal with them has become crucial for the industry. This prompted us to propose an approach based on community involvement in the decommissioning processes and the introduction of the social license for closure (SLC). By engaging the community, the SLC gives it a voice, allowing it to accommodate the individual needs of mining regions and ensure a successful and just transition. This article recognizes the key stakeholders and their fears related to the liquidation of mining. The organizational framework for stakeholder approval of the SLC is presented. The analysis was based on the example of Poland, a country facing the challenge of closing hard coal mines. Conclusions formulated on the basis of the case study complement the existing research in the field of social licensing and involving stakeholders in the mine closure planning process in accordance with the idea of corporate social responsibility.

Stability analysis of a closed underground hard rock metal mine using Finite Element Method

Active deep hard rock metal mines with long mining history come with inherent problems of stability and mining induced issues. These hard rock mines once closed, still pose even greater environmental risks and stability concerns. The issues of post-mining impact on environment are usually undervalued and disregarded. It is very essential to give utmost importance to these mines by following standard mine closure methods and remediations using post-mining management plans for long-term monitoring and risk assessments associated with the mine for the safety of life and structures above. The area identified for the study is Kolar Gold Fields mine located in Karnataka, India. The mine was completely closed in 2000. The underground mine has been posing post-mining induced seismicity even today. Due to the complexity of the underground mine and the inaccessibility to the mine post closure, the Finite Element Method of approach has been used. The approach is developed to simulate a model similar to actual field conditions, subjecting them to the seismic loads, varying the parameters which play a significant role, assessing the entire Kolar Gold Fields mines for vulnerable zones subjected to post-mining induced effects and finally making it possible to evaluate the stability conditions of the deep hard rock underground metal mine. The simulations were carried out for the three cases with varying the peak ground acceleration (PGA) for a low PGA of 0.06g, for an intermediate PGA of 0.1g and high value of 0.2g. It can be inferred that as the acceleration is increased from 0.06g to 0.22g, there is a corresponding increase in ground acceleration observed at the ground surface for each case. The maximum acceleration for PGA of 0.06g is 0.071g, for PGA of 0.10g, it is 0.170g and for PGA of 0.22g it is 0.266g. The results were validated with the field observations (data of seismicity from installed seismic monitoring systems). The Finite Element Method of approach has aided in quick assessment of stability of the underground closed mine.

Оцінка зменшення парникових газів вугільним сектором України для иконання міжнародних кліматичних угод

According to data from the National Greenhouse Gas Inventory, the coal sector is the second largest source of methane emissions in Ukraine after the oil and gas sector, its share in 2019 amounted to 17.8% of total methane emissions in the country. In 2022, Ukraine, as a Party to the Paris Agreement, submitted an updated value of the nationally determined contribution - to reduce greenhouse gas emissions by 2030 to 35% compared to 1990. In addition, it was formally launched the Global Methane Pledge, an initiative to reduce global methane emissions. Ukraine has joined this Pledge and make commitments to reduce methane emissions by 30% from 2020 levels by 2030. To assess the country's ability to meet its commitments to reduce greenhouse gas emissions in general and methane in particular, forecasts of the functioning of the coal sector were developed both in Ukraine and in the temporarily occupied territories on December 1, 2021. In decarbonisation scenario the development of the economic also took into account the commitment made by Ukraine at the 26th Conference of the Parties to stop the construction of new coal-fired power plants and to abandon the use of coal fuel by 2035. The dynamics of mine closure was analyzed according to the scenarios considered, and methane emissions were calculated not only from operating mines, but also from decommissioned mines. The results of the calculations show that achieving the declared reduction of methane emissions by 2030 in the coal sector is possible only if the capture and utilization of this greenhouse gas from the current 10.3% to 37-54% for different scenarios of the sector, which will require additional investment from 10 to 26.9 billion USA dollars depending on the scenario. Keywords: Greenhouses gases, Coal sector, Global Methane Pledge, second Nationally Determined Contribution

Mine closures and local diversification: Job diversity for coal-mining areas in a post-coal economy

This paper tries to shed light in the research that relates mining activities and regional diversification by studying how a group of local economies heavily specialized in mining diversified its economy after the ending of public subsidies that supported coal extraction. The case of study are the mining municipalities located in the center of Asturias (an autonomous region in Northern Spain), which constituted one the most important coal basins in the country. Although the extraction of coal was one of the main driving forces of the economic activity of the region, the mine pits were located in just a few municipalities across the territory. The economy of this area experienced the most severe effects produced by this policy, which started to be implemented in the early nineties and that gradually led to the cease of coal extraction in 2018. According to recent literature (see Fitjar and Timmermans, 2019), this shift in the public mining policy should have produced a greater diversification in the local economies previously specialized in mining activities, but a proper measurement of this effect can be problematic. Traditional methods, as difference-in-differences, are precluded due to the small number of spatial units directly affected by the treatment. This paper applies the estimation strategy proposed in Abadie and Gardeazabal (2003) of the Synthetic Control Method (SCM) to overcome this problem. The application of the SCM generates a weighted average of the untreated units (non-mining municipalities) that closely matches the treated unit over the pre-treatment period. Outcomes for this synthetic control are then projected into the post-treatment period using the weights identified from the pre-treatment comparison. This projection is used as the counterfactual for the treated unit. This methodology will be exploited together with rich historical data on local employment classified by industry, available for all the municipalities of the region for the period 1978-2018. The level of diversification on each area is quantified by calculating a Herfindahl-Hirschman Index (HHI), being this indicator the variable of interest. Taking the initial years of the 1990 decade as the break-point (when the policies of public support to coal extraction started to end), the application of this technique shows how this sped-up the diversification of the mining area, producing significant differences on the HHI with the counterfactual synthetic unit and indicating that the level of concentration of the economic activity is significantly lower than it would be if the mining activity had prolonged over time.

Design of a Lake Landscape in the Rhenish Lignite Area due to the Earlier Closure of Lignite Mines

Design of a Lake Landscape in the Rhenish Lignite Area due to the Earlier Closure of Lignite Mines

Geotechnical Issues in Decommissioning Surface Lignite Mines—The Case of Amyntaion Mine in Greece

Recent changes in the fossil-fuel energy sector require coal mining industries to plan for the future, including developing procedures for decommissioning and closure associated with mines. In surface coal mining, the geotechnical issues of decommissioning include the long-term stability of the pit slopes, particularly as the pit is gradually filled with water. This paper investigates such slope stability issues, with emphasis on the conditions prevailing in the Amyntaion surface lignite mine, in Western Macedonia, Greece. Analytical and numerical methods have been developed and used to estimate the temporal evolution of the overall safety factor, as the water level in the pit rises, creating a lake. It is shown that until the water level in the lake reaches a critical depth of approximately 15–35% of the final equilibrium condition, the safety factor against the overall slope instability decreases slightly (by about 3% in the case study, and up to 5–10% in other conditions) compared to its value at the end of exploitation. At higher lake levels, the safety factor increases significantly, as the beneficial effect of the lake water pressure acting on the slope overcomes the adverse effect of pore water pressure rise inside the slope. In typical mines, the critical water depth is achieved within a few years, since the surface area of the pit is smaller at deeper levels; thus, more favorable slope stability conditions are usually reinstated a few years after mine closure, while the small reduction in safety during the initial stages after closure is inconsequential. The paper investigates the parameters influencing the magnitude of the small reduction in the short-term safety factor and produces normalized graphs of the evolution of the safety factor as the lake water level rises. The results of the analyses can be used in preliminary closure studies of surface coal mines.