Coal Mining Operations Research Articles

Geotechnical Perspective on Dozer-Push Method in Coal Mining Operations

The rapid increase of technological development is currently playing a role in the mining industry. The dozer push exploitation method is an alternative to the conventional truck and shovel method. Heavy dozers have the ability to move large amounts of waste material in short distances at a low cost, while trucks and shovels will be more economical if over long distances. Geotechnical assessment becomes one of the critical considerations in making a decision plan and slope design for mining activities where the dozer push activities were carried out. Material conditions greatly affect slope stability, which can be defined as material behavior based on the physical and mechanical properties of the material. The slope stability analysis method used in this study was a combination of two methods, the Limit Equilibrium Method (LEM) and Finite Element Method (FEM). These two combinations of analytical methods will strengthen the justification of the geotechnical perspective. By understanding the behavior of the material on a slope, the risk of a slope failure can be controlled and minimized using a geotechnical perspective. The parameters that will be studied in this study are the physical and mechanical properties of the material against several conceptual design options

The Impact of Coal Exploitation on Tidal Flat Changes, an Investigation Using Remote Sensing Data in Vietnam

Tidal flat plays a crucial role in socio-economic development and ecological environment.Tidal flats in Ha Long-Cam Pha in Vietnam are impacted by human activities, especially coal miningactivities. Using remote sensing data is able to detect, extract, and monitor the changes of tidal flats andexploited coal mine area with multi-temporal, in various scales, and for a large coverage. This studyaims to investigate the impact of coal mining activities on the changes of tidal flats using remote sensingin Cam Pha, Ha Long, one of the biggest coal basins in Vietnam. Digital Elevation Models (DEMs) oftidal flats constructed by Landsat satellite images acquired in years 1989, 2001, and 2014 are comparedto determine the volume changes. Besides, coal mining activities including coal production, waste rockdump area, and the expansion of open coal mine during the period 1989-2014 are investigated usingcorrespondent Landsat images and the reports from the coal mine companies in the study area. Sedimentsamples in tidal flats are analyzed to determine the origin of the sediments. As the results, organic matterin the tidal flats is dominant with the concentration of 459 g/kg to 607 g/kg, which is evidence for theimpact of coal exploitation on the coastal environment. In addition, the relationship between coal mineactivities and tidal flat variation is well observed in this study.

Investigation on the Failure Mechanism of Weak Floors in Deep and High-Stress Roadway and the Corresponding Control Technology

Large deformation of roadway and floor burst are the two major geotechnical hazards encountered with high mining stress in deep mines. In this paper, the stress and energy conditions generated by the impact damage on the rock surrounding a roadway are analyzed, and UDEC software was used to study the deformation characteristics of the roadway, as well as its failure mechanism under the influence of superimposed dynamic and static loads. The results indicate that the soft floor of a deep-buried roadway has a high damage degree and an obvious stress release effect, high static load leads to slow floor heave, and strong dynamic load disturbance is the principal trigger leading to floor burst. In addition, the anisotropy caused by the bedding surface weakens the cooperative characteristics of the support system, resulting in serious instability of the whole rock surrounding the roadway. Full-section anchor cables and inverted arches were adopted to maintain the stability of the rock surrounding the roadway. The monitoring results obtained from field tests show that the adoption of the combined support system effectively avoids floor burst caused by the superposition of dynamic and static loads; the maximum floor heave is 67.9 mm, which is 95% lower than the original value, ensuring safety in coal mining operations.

Dual-Frequency Induction Polarization Electric Field Focusing Based on Intelligent Algorithm for Coal Mine Electric Exploration

As the most important and dangerous front-end production link, coal mining operations will inevitably face geological disasters such as water inrush, rock burst, collapse, and fire, posing a great threat to the life and safety of miners. Among the five major geological disasters (gas, dust, water, fire, roof) in coal mines, the threat of flooding is very serious and it is one of the main disasters in coal mines. The research and development of dual-frequency excitation technology and its application in coal mine exploration have realized the elimination of potential safety hazards, improved the work efficiency and safety factor of prospectors, and realized the automated operation of the exploration process. This article explores the electric field of the intelligent algorithm’s focused dual-frequency induced polarization method in coal mine electrical exploration, and summarizes some of the advantages of the intelligent algorithm’s focused dual-frequency induced polarization method in coal mine surveying on related materials, and then conducts related experiment, through the experiment of focusing on the dual-frequency IP method in the coal mine survey, obtained the result, in the abnormal point detection experiment, the change trend of the two curves is the same, the increase is more obvious at 1.3-1.5m, and at 1.5m When reaching the limit value, when it exceeds 1.5m, it starts to fall. It shows that when there is a water-bearing anomalous body directly in front of the tunneling section, the measurement results of the two survey lines are roughly the same. Compared with the no anomaly body, the apparent resistivity and the apparent amplitude frequency both change significantly, and reach the extreme in a certain direction. However, the actual anomalous body is located 1.0m directly in front of the tunneling section, which means that the actual position of the anomaly cannot be determined based on the apparent resistivity and the extreme point position of the apparent amplitude frequency.

Building 3D model for the deep vertical shaft in Nui Beo coal mine using Terrestrial laser scanning technology

Nowadays, deep vertical shafts have been built normally in Vietnam’s underground coal mines. During the operation of the underground coal mines, the deep vertical shafts must check periodically. With the advantages of fast measurement, high accuracy, point cloud data, the ability to process data by other specialized software, etc. Terrestrial laser scanning technology has allowed building 3D models for deep vertical shafts and used for other different purposes. In this present, by using Topcon's equipment and software, the process of establishing a 3D model for the main vertical shaft of the Nui Beo coal mine at a depth of 400 m was indicated. The simulation results have the cumulative error of sampling interval of stations not more than 4 mm, and the average position deviation of the aim direction relative to the vertical is 8.3 mm.

Mental Fatigue and Its Associated Factors among Coal Mining Workers after One Year of the COVID-19 Pandemic in Indonesia

Mental fatigue among coal mining operators was related to driving activities that require high concentration. This study aimed to determine factors that contributed to mental fatigue among coal mine operators in Indonesia, specifically in Kalimantan and Sumatra, after a one-year COVID-19 pandemic. This cross-sectional study was conducted among 480 operators from two companies and seven sites. A self-administrated questionnaire in the Google Form was used to measure mental fatigue, the non-work-related factors (age, education, marital status, residence, and stress level), and work-related factors (working periods, shift pattern, type of shift, and work area in mining). The data analyzed using Chi-square and binomial logistic regression showed that the prevalence of mental fatigue was 32.3%. Operators with moderate stress and working in the pit area demonstrated a significant association with mental fatigue (p-va lue<0.001). Multivariable analysis showed that medium stress (ORadj: 2.11, 95% CI: 1.41 to 3.15) and working in the pit (ORadj: 2.27, 95% CI: 1.45 to 3.57) had a positive association with mental fatigue. Thus, the pit condition and stress levels were the dominant factors influencing mental fatigue and became points to manage mental fatigue in coal mining operators in Kalimantan and Sumatra.

Variability in air-pollutants, aerosols, and associated meteorology over peninsular India and neighboring ocean regions during COVID-19 lockdown to unlock phases

The study focuses on the variability in aerosols, air-pollutants, and associated meteorological characteristics over peninsular India and neighboring ocean regions during both lockdown (25 March-31 May) and unlock (June–September) periods in 2020. During first lockdown phase, 40–60% reduction in aerosol loading observed over most parts except central-west India and the southern BOB. HYSPLIT model-based ‘back trajectory’ suggests the increase in anthropogenic aerosols over BOB due to long-range transport from an elevated layer. During second lockdown phase, an increase in AOD found over the eastern parts of India might come from the continuous operation of coal-fired thermal power plants and coal mines, besides domestic emissions. A surge in sea salt aerosols over BOB during the last two lockdown phases could be due to the Amphan super cyclone. During unlock phases, only natural aerosols show significant variation over the coastal and neighboring ocean regions with the simultaneous presence of intense summer monsoon. However, anthropogenic aerosols increased over the inland areas, which is most prominent in second and fourth unlock phases and could be attributed to the long-range transport. Temporal analysis of particulate matters and gaseous pollutants over coastal cities suggests Ahmedabad to be the most polluted one. The highest fall in NO2 was observed over Mumbai, whereas O3 concentration was appreciably enhanced over Ahmedabad, Visakhapatnam, and Chennai. Besides low anthropogenic emissions, long-range transport and prevailing meteorological conditions also played a significant role in governing the observed changes in aerosol loading and air pollutant concentration.

Improvement of technological processes for mining solid mineral resources

The object of research is the technological processes of the development of deposits and the extraction of solid minerals by underground and open-pit methods. The improvement of technological processes is achieved through the use of existing original technical solutions, which are currently advisable to use in practice. The work is aimed at increasing the efficiency of explosive energy use, improving the technological processes of mining operations in coal mines and open pits of mining enterprises. In the course of the study, an analysis of technical literature on mining topics was used, a search for copyright certificates for inventions and patents on the same topic was carried out. There was a search for innovative solutions that are expedient to apply at the present time. In the course of the analysis, the work shows ideas, methods of coal mining, systems for the development of coal seams, methods of destruction of rocks, microbiological reclamation and other new technologies and devices. The most promising technologies have been proposed for in-depth study, implementation and use in appropriate mining and geological conditions. The proposed technologies, for various reasons, have not yet found wide practical application at mining enterprises. Due to the application of the proposed technical solutions and technologies in practice in the conditions of existing coal mines and open pits, significant economic, environmental and financial effects can be obtained. This study was carried out in order to bring to a wide circle of specialists technical solutions that can contribute to a significant improvement in the technology of mining solid minerals, both in underground and open-pit mining all over the world.

Development Area for Floating Solar Panel and Dam in The Former Mine Hole (Void) Samarinda City, East Kalimantan Province

<p class='IJASEITAbtract'>This study discusses using a multi-criteria decision model (MCDM) to determine a suitable area for floating solar panels and dams in former mine holes (voids) in Samarinda City. The existence of open coal mining activities causes damage to the surrounding environment. One of the damages is the formation of former mine holes (voids). The voids can be detected by satellite imagery. Samarinda City has hundreds of voids and has the potential to increase. Therefore, this study aims to describe areas that can become areas for developing floating solar panels and dams. In this study, MCDM was implemented using Fuzzy GIS (a technique that integrates Fuzzy Logic and GIS) concepts. Fuzzy GIS is used to determine the suitability area of several predetermined criteria. The land suitability criteria are classified using the Fuzzy Membership and the Fuzzy Overlay process. The results showed that there were 442 voids with a total area of 7,901 km². The suitability of floating solar panels and dams is divided into four classes, namely S1, S2, S3, and N. The number of voids in the suitability class of floating solar panels is 17, 26, 40, and 359 respectively. The number of voids in the suitability of the dams are 45, 133, 210, and 54, respectively. The majority of voids are spread in areas with low accessibility with more distances from 1 km, are in an area with high enough solar radiation with 1800-1900 kWh/m2/year, and are in an area with a slope of more than 10%.

Borehole measurements of adsorbed gas content in coals using stimulated diffusion nuclear magnetic resonance

We present an NMR measurement technique which has the unique ability to determine the in-situ adsorbed gas concentration within coal seams. The measurement of adsorbed gas content is of critical importance for operational safety and commercial resource evaluation in the development of coal mining operations and coal seam gas (CSG) resources. The current measurement technique involves laboratory core analysis, using a canister desorption measurement which is subject to significant measurement uncertainty due to the gas lost between coring and analysis. The NMR measurement technique enables in-situ measurement of fluid content within the coal seams without disturbing the coal seams. The technique utilises the stimulated echo diffusion editing (SEDE) pulse sequence which simultaneously captures relaxation and diffusion behaviour of fluids contained within coal seams. In this work, we have optimised the SEDE pulse sequence by using two diffusion times which are appropriate for capturing the diffusive behaviour of water and adsorbed gas. The measured signal captured by the SEDE sequence is inverted to provide a T2-StimD distribution. The appropriate interpretation of the T2-StimD distribution enables the determination of the free and adsorbed gas concentrations. The adsorbed gas concentration measured using the optimised SEDE sequence shows very good agreement with core canister desorption measurements. The sequence also enables the detection of free gas which is important for understanding the depressurisation of the coal seams and the impact on development strategies.

Assessing toxic metal chromium in the soil in coal mining areas via proximal sensing: Prerequisites for land rehabilitation and sustainable development

The rapid and accurate determination of soil chromium (Cr) is crucial for preventing toxic element pollution in soils and ensuring ecological security. Proximal sensing technology uses visible and near-infrared (Vis-NIR) diffuse reflectance spectroscopy, which has been demonstrated to be a viable approach for monitoring soil Cr concentrations. However, at trace levels, soil Cr is not especially spectrally active, thus limiting the practical application of using corresponding spectral data for quantifying soil Cr concentrations. In this study, we hypothesized that fused proximal sensing and soil auxiliary attributes (including organic matter (OM) and pH) could improve estimation of Cr concentrations in the soil. Additionally, the introduction of best-fit variogram models was theoretically possible to improve spatial visualization. To address these hypotheses, we collected 168 soil samples from the open coal mine area in the Eastern Junggar Basin, China. Fractional-order derivative (FOD) pretreatment and optimal band combination methods were implemented for spectral data mining and the derivation of spectral parameters, respectively. Soil Cr estimation models were calibrated with a partial least squares (PLS) approach through four designed strategies with different predictors: (I) full Vis-NIR variables, (II) effective three-band spectral indices (TBIs), (III) the effective TBIs and OM, and (IV) the effective TBIs, OM, and the pH. The results suggest that FOD could identify abundant spectral variability. Compared with full Vis-NIR variables, the effective TBIs can effectively magnify the subtle spectral signals concerning soil Cr. The optimal estimation model was determined as Strategy IV, indicating that the introduction of soil auxiliary attributes (pH and OM) can improve the estimation performance of the model; notably, the coefficient of determination (R2) and ratio of performance to interquartile distance (RPIQ) were 0.87 and 2.68, respectively. Based on the optimal semivariance model, we used kriging interpolation to map regional soil Cr. In the study area, the soil Cr distribution features strong spatial dependence and strong associations. Our study might inspire further research on soil contamination mapping based on proximal Vis-NIR sensors.

Application of Indicator Kriging to hydraulic head data to test alternative conceptual models for spring source aquifers

Hydraulic head distributions can inform spring source-water characterisation by determining whether aquifers meet the thresholds required to sustain spring flow. Assessing hydraulic head data can be challenging in areas where data are sparsely distributed and subject to variable measurement uncertainty. Geostatistical methods can be used to estimate hydraulic head values at unmeasured locations with quantitative uncertainty estimates. While these methods have been applied extensively for hydraulic head estimation in management contexts, no studies have used these approaches for spring source-water conceptual model testing. In this study, an investigation into the hydraulic head distribution was conducted through the application of Ordinary Indicator Co-Kriging. Interpolated hydraulic head estimates were used to quantitatively assess the plausibility of source-aquifer conceptual models for the Doongmabulla Springs Complex (DSC), Queensland, Australia. The results offer insights into the likelihood of alternative source aquifers having adequate head to support flow to eight springs within the DSC. Probabilities of adequate head to support the springs ranged from 0.03 to 0.12 for the Permian Formations, compared to <0.01 to 0.49 for the Triassic Formations. Analyses indicated that the Triassic Formations are more likely to have adequate hydraulic head to support spring flow. However, significant uncertainty exists in the conceptual model assessment due to hydraulic head measurement scarcity, particularly in the vicinity of the springs. These findings have important implications given that the Permian Formations will be dewatered by the operation of the nearby Carmichael coal mine. The techniques employed here can inform conceptual model uncertainties arising from the interpretation of sparsely distributed hydraulic head datasets, a major benefit over traditional interpolation methods.

Research on Torque Control System Based on Fuzzy Logic

Aiming at the needs of intelligent coal mining and construction of intelligent mines, based on fuzzy control language, the torque parameter control system of intelligent drilling rigs is analyzed and researched. The structure of the torque output fuzzy control system and the fuzzy adaptive PID controller are designed, and the system is simulated. The simulation research provides new ideas for the development of actual hardware controllers in the future, and lays the foundation for realizing unmanned operations in coal mines.

Operating Environment Assessment of the Coalface in Underground Coal Mining Based on Analytic Hierarchy Process (AHP) and Matter-Element Theory (MET)

The environmental evaluation of the coalface in underground mining is of great significance to the safety of production and the health of miners. In order to achieve the objective and accurate evaluation of the operating environment of the coalface, the indexes of temperature, humidity, noise, illuminance, dust, harmful gas, and wind speed are selected to construct the environment evaluation index system, and the operating environment evaluation model of the coalface based on analytic hierarchy process (AHP) and matter-element theory (MET) is established. Firstly, the operation environment classification criterion is established; the environment objects, joint domain, and classical domain mater-element are built; and the correlation function is calculated. Secondly, the comprehensive correlation matrix is calculated and the environmental grade is judged. Finally, from the broad point of view, three measures are proposed to improve the operation environment of the coalface: development of the environmental evaluation index monitoring system, improvement on miners’ safety awareness, and formulation of regulations and policies for coal mine operation environment. The research results can provide guidelines for miners, coal mining enterprises, and occupational environmental safety departments.

Resettlement, intergenerational memory, place attachment, and place identity in Roșia Jiu coal mine - Gorj County, Romania

The present study was conducted in a traditional mining area in Romania-the Rovinari Carboniferous Basin-from which in 1976 the communist authorities relocated about 800 people, two churches, and a cemetery to a new location in the village of Iași, Gorj County, in order to expand coal mining operations. Using the triangulation method, we gathered data from 139 questionnaires, 30 interviews, and ethnographic observations to highlight the ways in which the traumatic memories of the communist period are evoked today by the displaced population and perceived by the younger generation. Apart from some post-communist memories that cast the communist regime in a positive light, respondents largely condemned the regime, which, by threatening to take away their work, forced them to move to a new location. This relocation had profound implications in respondents' personal and family mentality represented first by the destruction of local cultural property or heritage and later by the appearance of trauma and respondents’ implicit attachment to the places they had lost. The history of those times is taught through the intergenerational transmission of memories at home as a place of family identity or at church as the centre of spirituality for the Romanian village.Bringing household items from the old destroyed location to the new location strengthened respondents’ postcommunist memory and helped to heal or alleviate their past trauma. However, beyond the differing political considerations expressed by those we interviewed and questioned, the complexity of post-communist memory, whichis tense and nuanced, remains relevant under deeper scrutiny.

Incommensurability and corporate social technologies: a critique of corporate compensations in Colombia's coal mining region of La Guajira

Extractive industries increasingly use compensation measures to silence opposition, divide communities and stop resistance. Cerrejón, Colombia's largest transnational coal mining corporation, has a long history of damaging Indigenous Wayúu, Afro-Colombian and local communities' health and livelihoods. In the northeastern Colombian region of La Guajira, local communities struggle against the social and environmental impacts of coal mining. This article, based on field research conducted between 2018-2019, concludes that corporate and state-backed consultation and compensation projects are incommensurable with the damage caused by the coal mining operations and are implemented as a corporate social technology that undermines community cohesion and reinforces a power imbalance, perpetuating and enabling the expansion of damaging coal mining practices in Colombia.

Influence of acetylene on methane\u2013air explosion characteristics in a confined chamber

To study the impact of acetylene on methane explosions, the safe operation of coal mines should be ensured. In this paper, a 20 L spherical tank was used to study the explosive characteristics of acetylene–methane–air mixture. In addition, the GRI-Mech3.0 mechanism was used to study the chemical kinetic mechanism for the mixed gas, and the effect of adding acetylene on the sensitivity of methane and the yield of free radicals was analysed. The results show that acetylene can expand the scope for methane explosion, lower the lower explosion limit, and increase the risk of explosion. Acetylene increases the maximum explosion pressure, laminar combustion rate and maximum pressure rise rate for the methane–air mixture while shortening the combustion time. Three combustion modes for the acetylene–methane–air mixture were determined: methane-dominated, transitional and acetylene-dominated combustion modes. Chemical kinetic analysis for the mixed gas shows that as the volume fraction of acetylene increases, the generation rate for key free radicals (H*, O* and OH*) gradually increases, thereby increasing the intensity of the explosive reaction. The results from this research will help formulate measures to prevent coal mine explosion accidents.

Application of Synthetic Aperture Radar Interferometry to monitor surface deformations of the Trans-European Transport Network (TEN-T) – A case study of the motorways crossing areas of mining operations in the Upper Silesian Coal Basin, Poland

Underground hard coal mining causes surface deformations. When the mining operations are conducted beneath linear objects, such as motorways, there is a risk of deformations of the axis of the road and its horizontal and vertical alignment (additional bends and vertical curvatures, longitudinal inclinations, deformations of crosssections). In the areas subjected to mining operations, mining plants conduct geodetic monitoring. Due to their labour intensity and costs, geodetic measurements are usually made only a few times a year. The article discusses the possibility of applying Interferometric Synthetic Aperture Radar (InSAR) to monitor the subsidence of the vertical alignment of motorways caused by mining operations and its advantages and disadvantages compared to the currently used methods of geodetic measurements. The tests were conducted in two sections of motorways within the Upper Silesian Coal Basin (Poland) in the areas of intensive hard coal mining operations. Radar imaging of the surface made by the European Space Agency's (ESA) satellite Sentinel-1 equipped with the Synthetic Aperture Radar (SAR) was used.

Mining Industry Impact on Environmental Sustainability, Economic Growth, Social Interaction, and Public Health: An Application of Semi-Quantitative Mathematical Approach

The mining industry plays a significant role in economic growth and development. Coal is a viable renewable energy source with 185.175 billion deposits in Thar, which has not been deeply explored. Although coal is an energy source and contributes to economic development, it puts pressure on environmental sustainability. The current study investigates Sindh Engro coal mining’s impact on environmental sustainability and human needs and interest. The Folchi and Phillips Environmental Sustainability Mathematics models are employed to measure environmental sustainability. The research findings demonstrated that Sindh Engro coal mining is potentially unsustainable for the environment. The toxic gases (methane, carbon dioxide, sulfur, etc.) are released during operational activities. The four significant environment spheres (atmosphere, hydrosphere, biosphere, and lithosphere) are negatively influenced by Thar coal mining. The second part of the analysis results shows that human needs and interests have a positive and significant relationship except for human health and safety with Sindh Engro coal mining. Environmental pollution can be controlled by utilizing environmentally friendly coal mining operations and technologies. Plantation and ecological normalization can protect the species, flora, and fauna of the Thar Desert. The government of Pakistan and the provincial government of Sind should strictly check the adaptation of environmental standards. Furthermore, the researchers should explore the environmental issues and solutions so that coal mining becomes a cost-efficient and environmental-friendly energy source in Pakistan.

Trace element partitioning during coal preparation: Insights from U.S. Illinois Basin coals

A suite of 72 samples of Illinois Basin coal was collected from 2015 to 2018, from 14 active coal mining and preparation operations in Illinois and Indiana. The goals of the study were to investigate the behavior of trace elements during coal preparation and provide current coal quality data for active mining operations in the Illinois Basin, which has become one of the most important suppliers of U.S. coal. Samples include raw coal, cleaned coal, and waste (refuse) coal. The efficiency of cleaning is shown by reduction of ash yield, increase in heating values, and a pronounced shift in the proportion of sulfur forms. In most raw coals, pyritic sulfur (Py S) exceeds organic sulfur (Org S; Org S/Py S ≤ 1.0), whereas in prepared coals, organic sulfur is the predominant sulfur form (Org S/Py S ≥ 1.0). In waste (refuse) coals, Org S/Py S is substantially reduced, or almost entirely in the pyritic form (Org S/Py S near zero). Trends in the distribution of inorganically-associated lithophile and chalcophile elements are shown, as well those for elements having mixed organic-inorganic associations and those that are primarily organic-hosted. Lithophile elements, including Li, Al, P, Ti, Sc, Rb, Y, Zr, Nb, Cs, Ba, the lanthanides, Hf, Th, and U, are partitioned into waste coals with corresponding reduction in cleaned coals. At the same time, chalcophile elements hosted by pyrite, such as As, Sb, Hg, and Pb, are also partitioned into waste coals. Rare earth elements (REEs), including Sc, Y, and the lanthanides, are enriched in waste coals at levels that approximate their content in the upper continental crust (UCC). Several other critical elements, defined as mineral commodities deemed critical to the economy and security of the United States, including V, Cr, As, Rb, Sb, and Cs, show enrichment in waste coals, that may facilitate their co-extraction with the REEs. Concentrations for elements of environmental concern in cleaned coals are similar to or below those for world average coals with the exception of Pb in coals from Illinois. Laser-ablation ICP-MS (LA-ICP-MS) for pyrite in a subset of 21 samples of raw and cleaned coal provided direct determinations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Au, Hg, Tl, Pb, and Bi. LA-ICP-MS was used together with bulk sample pyritic sulfur and trace element concentrations to estimate the elemental proportion of bulk Cu, As, Hg, and Pb in pyrite, indicating that Hg and Pb are hosted almost entirely by pyrite, whereas the proportion of Cu and As in pyrite accounts for about half of the bulk content. With growing interest in recovering critical elements from coal, partitioning of a large range of elements into waste coals presents a possible opportunity, but also a potential hazard, due to enrichment in harmful elements such as Hg, As, and Pb.