Mine Waste Management Research Articles

Management of Mining Wastes and Interest of their Recycling in Construction Materials: Case of White Slag from Steel Mills of EL Jadida in Morocco

Management of Mining Wastes and Interest of their Recycling in Construction Materials: Case of White Slag from Steel Mills of EL Jadida in Morocco

Recycling and Reuse of Mine Tailings: A Review of Advancements and Their Implications

Mining is an important industry, accounting for 6.9% of global GDP. However, global development promotes accelerated demand, resulting in the accumulation of hazardous waste in land, sea, and air environments. It reached 7 billion tonnes of mine tailings generated yearly worldwide, and 19 billion solid tailings will be accumulated by 2025. Adding to this, the legacy of environmental damage from abandoned mines is worrying; there are around 10,000 abandoned mines in Canada, 50,000 in Australia, and 6000 in South Africa, as well as 9500 coal mines in China, reaching 15,000 by 2050. In this scenario, restoration techniques from mining tailings have become increasingly discussed among scholars due to their potential to offer benefits towards reducing tailing levels, thereby reducing environmental pressure for the correct management and adding value to previously discarded waste. This review paper explores the available literature on the main techniques of mining tailing recycling and reuse and discusses leading technologies, including the benefits and limitations, as well as emerging prospects. The findings of this review serve as a supporting reference for decision makers concerning the related sustainability issues associated with mining, mineral processing, and solid waste management.

Mobility of Be, Bi, F, Ga, Ge and W in Surface Water and the Water Quality Impact on Epilithic Diatoms Downstream of the Historical Yxsjöberg Mine Site, Sweden

There is a potential risk that the geochemical cycles of several critical metals will be affected when mining of these metals increases to meet the demand of green technology. The geochemistry of Be, Bi, Ga, Ge, and W, herewith called CM5, is lacking, yet is necessary to ensure responsible mine waste and water management. Beryllium, Bi, and W are all considered immobile, but in previous studies of skarn tailings in Yxsjöberg, Sweden, all three elements were mobilized. The tailings are enriched in CM5, together with pyrrhotite, calcite, and fluorite. The mobility and environmental impact of CM5 and F in surface waters downstream of the Yxsjöberg mine site, Sweden, were studied using monthly water samples from seven locations and analysis of diatoms at five of these locations. Bismuth, Ge, and W were present at low concentrations, transported in the particulate phase, and likely settled in the sediments hundreds of meters from the tailings. Beryllium and F were present at high concentrations and dominantly transported in the dissolved phase. At these pH conditions (5.6), Be should form insoluble hydroxides; however, elevated concentrations of dissolved Be were observed more than 5 km from the mine site. Diatoms downstream of the mine site were negatively affected by the mine drainage. The release of low quality neutral mine drainage will continue for hundreds of years if remediation actions are not undertaken since only a small portion of the tailings have weathered during 50–100 years of storage.

Sulfide Variation in the Coeur Rochester Silver Deposit: Use of Geologic Block Modeling in the Prediction and Management of Mine Waste

Abstract A critical issue in mine waste management is the management and mitigation of acid rock drainage and metal leaching particularly from waste rock. This requires good understanding and characterization of materials most likely to generate acid pH waters and generate leachable metals and metalloids, as well as the presence of minerals most likely to neutralize acidic pH such as carbonates and certain silicates. For low-sulfidation epithermal deposits in silica-rich volcanic rocks, neutralization minerals are rare. Consequently, determination of acid generation is almost entirely a function of sulfide content of the rocks. By understanding the distribution of sulfide minerals within such a deposit, an initial mine waste management plan can be developed. The Rochester mine currently exploits a low-sulfidation epithermal gold-silver deposit and is located on the southern flank of the Humboldt Range in west-central Nevada. The Rochester mine is a conventional open-pit mining operation with cyanide heap leaching and Merrill Crowe processing. Silver and lesser gold mineralization occur associated with sulfide minerals hosted in Permian-Triassic Koipato Group rhyolitic units with extensive quartz-sericite-pyrite alteration. Gangue mineralogy of the deposit is dominated by slow or unreactive silicate minerals with little or no carbonate. Silver-bearing mineralization was controlled by primary hypogene sulfides and secondary supergene oxidation processes, and most of the mineralized material mined to date has been fully or partially oxidized. Oxidation mobilizes and depletes all forms of sulfur from primary sulfide minerals. Due to the low sulfate content and low content of neutralizing gangue phases, the waste rock classification can be based on total sulfur content. Based on the analysis of pulp samples collected from within the mine area, a sulfur block model was developed and compared to the results of standard acid-base accounting and net acid generation tests. This comparison demonstrates the benefit of the block model in identifying zones of potentially acid-generating material in the mined waste. Application of this information to mine planning has allowed more efficient management of acid-generating mine waste by allowing the operator to develop areas of the waste rock facility to receive the waste in a timely fashion. Such an approach is based on good mine geologic and mineralogical characterization and the use of a representative and comprehensive geologic block model.

Valorizing (cleaned) sulfidic mine waste as a resource for construction materials

Proper management and storage of mine waste, e.g., tailings and waste rock, is one of the main issues that mining industries face. Additionally, there is already an uncountable amount of existent historical mine waste, which may, even centuries after the closure of the mine, still be leaching contaminants into the environment. One solution to minimize the risks associated with the mine waste, with also potential economic benefits, is through the valorization of the waste. This can be done by first recovering valuable metals and removing hazardous contaminants. Then, the remaining residue can be valorized into green construction materials, such as geopolymers, ceramics or cement. For some mine waste materials, such as those with only trace levels of metals that are not economically viable to extract, the “waste” can be reused directly without this additional cleaning step. In the present study, mine waste originating from three different sites was characterized and compared with the cleaned mine waste (i.e., cleaned by bioleaching or flotation methods) and with different types of green construction materials containing 13–80 wt% (cleaned and uncleaned) mine waste. Particular emphasis was given to the mobilization of metal(loid)s from the mine waste and construction materials (i.e., ceramics, alkali-activated materials and cement) under different conditions, through a series of leaching tests (i.e., EN 12457–2, US EPA's Toxicity Characteristic Leaching Procedure, and a pH-dependent leaching test). The leaching tests were applied to either mimic current ‘natural’ conditions at the mining site, conditions in a landfill (end of life) or extreme conditions (i.e., extremely acidic or alkaline pH). Most of the original mine waste samples contain high levels of Pb (18–3160 mg/kg), Zn (66–10500 mg/kg), and As (10–4620 mg/kg). . The cleaning methods were not always efficient in removing the metal(loid)s and sulfur. In some cases, the cleaned mine waste samples even contained higher total metal(loid) and sulfur concentrations than the original mine waste samples. Based on the leaching studies, some alkali-activated materials, ceramics, and cement effectively immobilized certain metals (e.g., <0.5 mg/kg of Pb and <4 mg/kg of Zn). Also, longer curing times of the alkali-activated materials, in most cases, improved the immobilization of metal(loid)s. Additionally, for ceramics, the temperature at which the test pieces were fired (up to 1060 °C), also played a major role in decreasing the mobility of some metal(loid)s, while increasing others (e.g., As, potentially via the structural rearrangement of As and Fe). Overall, through this detailed characterization, the environmental impact from the mine waste to the downstream products was evaluated, determining which valorization methods are the most viable to close the circular economy loop.

Application of passive seismic interferometry for mapping mining waste storage facilities: A case study of Pyhäsalmi mine in Finland

Obtaining knowledge about the structural, geotechnical and hydrogeological conditions of mining waste storage facilities (e.g., tailing storage facilities, TSF) is an important task for mining waste management. From the existing applied geophysics techniques, high-resolution controlled source seismic methods are the most appropriate due to their superior spatial and depth resolution. However, the TSF areas are not often accessible for installation of seismic instruments and application of controlled source. Moreover, TSF areas in active mine sites are characterised by high-level of seismic and acoustic noise, produced by mining operations and other human activities at mine sites. In this study, we show that these problems can be addressed by utilizing passive seismic interferometry, in which cross-correlation of ambient seismic noise is used to obtain the Empirical Green's function (EGF's) of the studied medium. We used this method to evaluate seismic velocities in the TSF and in the near-surface bedrock at the site of the Pyhäsalmi underground mine in Finland. We used the ambient seismic noise recorded in two seismic experiments in the area. In the first experiment, the data were acquired in 2013 along a line 10 km long crossing the area of the underground mine. The second experiment was carried out in the TSF area in 2019. We obtained S-wave velocity models of both bedrock and the TSF by applying multichannel analysis of surface waves (MASW) to surface wave parts of Empirical Green's Functions (EGFs). The analysis of autocorrelation functions of passive seismic data recorded on the TSF surface allowed to us retrieve reflected arrivals from the boundaries inside the TSF. At the same time, we used amplitudes of surface wave parts of EGF's to obtain information about attenuation of surface waves in TSF. Our results show that passive seismic interferometry and interpretation of passive seismic data by different techniques can be a useful tool for inspection of TSF of active mines

Trialling one-part geopolymer production including iron ore tailings as fillers

ABSTRACT Mining is facing a transformation in terms of environmental and social performance with improved mine waste management practices required. The valorisation of iron ore tailings, a fine material rich in silica, should be sought as it can be used in geopolymers. In this study a methodology to produce a one-part geopolymer using iron ore tailings as fillers is presented. All experiments used 50 wt.% of tailings with varying proportions of activators tested. The best result of compressive strength achieved is 48.1MPa after 28 days curing at room temperature. This study demonstrates the potential application for using geopolymers as future construction materials.

Fractionation of Metal(loid)s in Three European Mine Wastes by Sequential Extraction

Mine waste can constitute an environmental hazard, especially when poorly managed. Environmental assessment is essential for estimating potential threats and optimizing mine waste management. This study evaluated the potential environmental risk of sulfidic mine waste samples originating from the Neves Corvo Mine, Portugal, and the closed Freiberg mining district, Germany. Metal(loid)s in the waste samples were partitioned into seven operationally defined fractions using the Zeien and Brummer sequential extraction scheme. The results showed similar partitioning patterns for the elements in the waste rock and tailing samples from Neves Corvo Mine; most metal(loid)s showed lower mobility, as they were mainly residual-bound. On the contrary, the Freiberg tailing sample had considerably elevated (24–37%) mobile fractions of Zn, Co, Cd, and Mn. The majority of Fe (83–96%) in all samples was retained in the residual fractions, while Ca was highly mobile. Overall, Pb was the most mobile toxic element in the three samples. A large portion of Pb (32–57%) was predominantly found in the most mobilizable fractions of the studied waste samples. This study revealed that the three mine wastes have contamination potential for Pb and Zn, which can be easily released into the environment from these waste sources.

Sequencing the waste: when rehandling can be a feasible option to open pit mines

ABSTRACT Mining waste management is progressively gathering attention as current waste disposal practices may cause substantial environmental impact. This study aims to evaluate a waste sequencing method, called Multi Stage Dumping Sequencing (MSDS), using a commercial sequencing software in a hypothetical copper deposit. This method uses temporary waste dumps (TWD) in the earlier stages of a mining project to reduce operational costs during this period, followed by a planned TWD rehandling schedule to a final destination. In this study, the method demonstrated the potential to reduce up to 39% of equipment acquisition investments in the first years of the operation.

A stochastic mixed integer linear programming framework for oil sands mine planning and waste management in the presence of grade uncertainty

ABSTRACT The primary purpose of oil sands mine planning and waste management is to provide ore from the mine pit to the processing plant while containing the tailings in an efficient manner in-pit. Incorporating waste management in the mine plan is essential to maximize the economic potential of the mineral reserve and minimize waste management costs. However, spatial variability such as grade uncertainty results in ore tonnage variations, which leads to fluctuations in the quantity of ore to be processed and waste to be managed. This paper investigates the application of a stochastic mixed integer linear programming (SMILP) on oil sands mine planning to integrate bitumen grade uncertainty and waste management. Sequential Gaussian simulation is employed to quantitatively model the spatial variability of bitumen grade in the oil sands deposit. Multiple simulated orebody models are used as inputs for the SMILP model to generate optimal mine plans in the presence of grade uncertainty. The results demonstrate that the SMILP schedule generates 14% and 17% improvements in net present value compared to the E-type and ordinary kriging schedules, respectively. These results indicate that the SMILP model is a robust tool for optimizing stochastic integrated oil sands production schedules and waste management.

A review of sustainable management of mining waste

A review of sustainable management of mining waste

A review of sustainable management of mining waste

A review of sustainable management of mining waste

An Overview on Solid Waste Generation and Management: Current Status in Chile

The widespread generation of, ever increasing volumes of and the sustainable management of solid wastes are global issues of great concern. Due to wide variations in composition and associated complexities, significant efforts are required for their collection, processing and environmentally safe disposal in a cost effective manner. An overview of solid wastes is presented in this article with a specific focus on municipal solid wastes and industrial waste from the iron/steelmaking and aluminium industries. Key waste issues such as its sources, compositions, volumes, the factors affecting waste generation and waste processing are first discussed, followed by a further discussion regarding recycling, resource recovery, disposal and the associated environmental impacts. In a special case study, waste generation and management in Chile is presented in greater detail. Detailed information is provided on government initiatives and legislation for integrated solid waste management and its movement towards a circular economy. Measures include regulations on waste management framework which concerns the transboundary movements of hazardous wastes, persistent organic pollutants, the closure of mining activities and installations and restrictions on plastics disposal. With Chile being world’s largest producer of copper, significant efforts for mining waste management, its infrastructure and procedures are being put in place to reduce the environmental impact of the mining sector and its associated waste generation.

The new expertise required for designing safe tailings storage facilities

The global mining community has seen a dangerous sequence of failures in tailings dams, beginning with Mount Polley mine, followed by the Samarco, Cadia Valley and Córrego do Feijão mines. This sequence of failures began on August 4, 2014, at the Mount Polley tailings storage facility in British Columbia, Canada. The initial failure in the embankment at the Mount Polley tailings storage facility had substantial impact on the global mining industry. The Independent Expert Engineering Investigation and Review Panel (IEEIRP) tasked with the investigation of the breach in the tailings dam at Mount Polley made major contributions for new guidelines. The incident has given rise to comprehensive recommendations for best available tailings technologies (BAT) based on principles such as the elimination of surface water from impoundments with the promotion of unsaturated conditions in the tailings through drainage provisions. The application of these BAT principles for the surface storage of tailings leads to the use of filtered tailings technology. Filtered tailings technology or “dry stack tailings” can satisfy each of the BAT components when the impoundment is properly designed and constructed. The implementation of the best available technologies for the physical stability (BAT-PS) of tailings impoundments competes directly with the best available technologies for the chemical stability (BAT-CS) of reactive tailings that may produce acid and metalliferous drainage. The new expertise in mine waste management required to achieve both BAT-PS and BAT-CS are discussed in the present paper.

A global-scale spatial assessment and geodatabase of mine areas

Despite massive growth in mining activity worldwide, efforts to assess the land use of mining at a global scale have been limited. Increasing satellite image quality and accessibility now permit detailed assessments of mine areas and their emerging geographical patterns. In this study, we produce a global-scale geospatial dataset of mine areas, comprised of 24,605 mine area polygons, mapped with high spatial precision in satellite imagery across 117 countries. Our dataset adds comprehensive detail on the global distribution, areal extent, and spatial form of mine areas, as well as new understandings of potential risks to surrounding areas. Our results reveal a total occupied land area of ~31,396.3 km 2 , averaging 1.3 km 2 per site. To illustrate potential insights enabled by our datasets, we performed detailed assessments of the geographical distribution of global mine areas in terms of their spatial density, elevations, and areas relative to rivers basins, climate zones, and human development factors. Our study promotes increasing access to high-quality spatial data to facilitate more systematic global management of mine wastes, pollution and mine land management. • 24,605 mine area polygons are delineated across 117 countries, covering 31,396.3 km 2 , at an average of 1.3 km 2 per site. • The spatial distribution of minareas differs between regions, with the highest spatial densities of mining (>100/1000 km 2 ) situated in the North China Plain and Western Australia. • Mine wastes are mostly (46.9%) situated from sea level to 400 m elevation, with an exponential decrease between 400 m and 650 m, linear decrease from 650 m to 2250 m, and the lowest occupancy above 2250 m. • Mine areas relative to rivers basins, climate zones, and human development factors are also explored.

Waste Management for Lunar Resources Activities: Toward a Circular Lunar Economy

Space resources activities are currently the objective of a thriving cross-disciplinary global effort aimed at assessing their role and potential in the future of humankind. New innovative mission concepts, legal frameworks, and advanced technologies are being actively developed and proposed with the final goal of enabling profitable and efficient space resource utilization. The immediate location for these impacts is the Moon. In sight of this bright cohort of imminent perspectives, it is imperative for the global community to properly assess the potential effects and consequences of the forthcoming space resources activities, with the goal of including sustainability in the foundations of the ongoing progress and ensuring its enforcement in every future endeavor. Within this context, this article addresses the topics of Moon mining waste management and a lunar circular economy as key issues in the sustainable utilization of space resources. The most promising technologies are considered for lunar resources extraction and processing—with special focus on water—correlating their waste generation potential to the scale of the efforts implemented and to the projected availability of the resources of interest. Importance is also given to the corollary activities of space mining—such as logistics and transport operations—for their implications in waste management. Protocols and technologies with the lower waste generation potential are identified and further scenarios are elaborated for waste handling, reduction, reuse, and recycle, as well as end-of-life strategies for mining plants. This report's recommendations are proposed for the development of incremental regulation for waste management, including but not limited to the definition of common areas of noninterest for waste disposal and regulatory obligations for conducting impact assessments before the establishment of mining activities. Please note that this abstract is submitted under the auspices of the Space Generation Advisory Council, as part of the activities of the Space Exploration Project Group.

Probabilistic multi-pathway human health risk assessment due to heavy metal(loid)s in a traditional gold mining area in Ecuador

Mining operations are important causes of environmental pollution in developing countries where mining waste management is not adequate. Consequently, heavy metal(loid)s are easily released into the environment, being a potential risk to human health. This study carries out a Bayesian probabilistic human health risk assessment, related to multi-pathway exposure to heavy metal(loid)s in a gold mining area in Southern Ecuador. Concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn in tap water, surface water, and soil samples, were analyzed to assess the potential adverse human health effects based on the Hazard Index (HI) and Total cancer risk (TCR). Adults and children residents were surveyed to adjust their exposure parameters to the site-specific conditions. Exposure to heavy metal(loid)s resulted in unacceptable risk levels for human health in the two age groups, both carcinogenic (TCR > 1 × 10−5) and non-carcinogenic (HI > 1) through ingestion of tap water and incidental ingestion of surface water. Sensitivity analysis showed that As concentration in waters and exposure frequency were the main contributors to risk outcome. Exposure to soil via accidental ingestion and dermal contact was below the safety limit, not posing a risk to human health. These findings can provide a baseline for the environmental management of the mining area and indicate the need for further research on As pollution in water and its implications on the health of the inhabitants of mining communities.

Valorisation of mine waste - Part I: Characteristics of, and sampling methodology for, consolidated mineralised tailings by using Witwatersrand gold mines (South Africa) as an example

The quest for steady primary supplies of critical raw materials (CRMs) creates significant waste, which is inevitably generated at each phase of mining and mineral processing. Waste from extraction, separation and refinement of non-renewable natural resources is accumulated globally and creates not only environmental hazards but also economic possibilities. Mine waste management is an expensive and prolonged task but unavoidable. Mine tailings, especially historical ones, can contain economically feasible resources, and given the right condition, such tailings could be reutilised through a waste valorisation concept. A prominent example are the Witwatersrand gold mine tailings in South Africa, which have been reused in small-scale projects. Tailing reutilisation is only possible if a sound classification, sampling and resource modelling framework is established to thoroughly and accurately profile the economic, environmental, health and geometallurgical aspects. Our study on valorisation of mine waste is presented in two parts: Here, in Part I, we focus on the essential components of a mine waste valorisation framework that includes the characterization and development of a systematic sampling framework for consolidated mineralised tailings. The development of a mine waste valorisation framework will hopefully enable worldwide reduction and reutilisation of mine waste.

Multi-stage dumping sequence - a feasible waste management alternative for open pit mining

Abstract Waste management and environmental aspects are progressively gathering attention in the mining industry. Mine planners must deal with increasingly complex tasks to balance between ore block schedules, waste disposal, operational cost and environmental reclamation. The mine incomes are generally related to mining and processing of the ore, thus most optimization researches regarding strategic mining usually focus mainly on ore extraction. Nevertheless, waste sequencing and disposal play an important role given that, in several situations in open pit mining, waste volumes are generally larger than ore volumes and must be moved to reach the buried and deeper ore bodies. In some cases, a significant percentage of operational costs is represented by waste haulage and disposal. Thus a careful planning strategy must be considered to minimize unnecessary expenses. Selecting locations for waste dumps is also a challenge. Many operational and technical aspects must be considered, not to mention the increasingly limiting environmental constraints. This definition can be very time consuming, and if it is not properly studied, may negatively impact the mine operation during its lifetime. This article investigates a new approach for mine waste management called the multi-stage dumping sequence (MSDS), suggesting the use of temporary waste dumps along the way to the final dump destination. Although this method requires material re-handling, which is considered a paradigm in mine industry, it certainly provides additional time to design and permit the final waste dump site and, if well planned, might even result in profit increases by reducing haulage distances in the first years of operation.

Occurrence and Release of Trace Elements in Pyrite-Rich Waste Rock

Waste rock can contain high concentrations of deleterious trace elements, which upon oxidation can be released, having a significant impact on water quality. Therefore, knowledge about their occurrence and overall mobility is crucial to ensure suitable environmental protection measures. Sulfide-rich waste rock was characterized and quantified using automated mineralogy (QEMSCAN). Selected pyrite grains were analyzed for trace element occurrence using LA-ICP-MS before, during, and after leaching the waste rock in 10 L small-scale test cells for two years to assess trace element occurrence and mobility. Sequential extraction was used to estimate elemental sequestration during the experiment. The high abundance of pyrite (66%) and scarcity of buffering minerals resulted in low pH (&lt;1.3) leachate with high concentrations of trace elements such as As (21 mg/L), Cu (20 mg/L), Hg (13 µg/L, Pb (856 µg/L), Sb (967 µg/L), Tl (317 µg/L ), and Zn (23 mg/L) in solution with limited retention in secondary minerals, primarily due to these elements’ association with pyrite either as inclusions or impurities showing an average abundance of 193 ppm As, 15 ppm Cu, 13 ppm Hg, 20 ppm Pb, 24 ppm Sb, 26 ppm Tl, and 74 ppm Zn in the waste rock. The occurrence of Cu and Zn as inclusions associated with the pyrite led to their extensive mobilization of 79% and 72%, respectively, despite their low abundance in the waste rock. Provided the overall leachability of S (11%) and limited formation of secondary minerals, the average oxidation rate suggests depletion of the pyrite within approximately 18 years. In conclusion, this study shows the importance of detailed mineralogical investigations and early preventive measures of waste rock to ensure sustainable mine waste and water management.