Coal Mining Operations Research Articles

The role of macrophage polarization and related key molecules in pulmonary inflammation and fibrosis induced by coal dust dynamic inhalation exposure in Sprague-Dawley rats

Coal dust is the main occupational hazard factor during coal mining operations. This study aimed to investigate the role of macrophage polarization and its molecular regulatory network in lung inflammation and fibrosis in Sprague-Dawley rats caused by coal dust exposure. Based on the key exposure parameters (exposure route, dose and duration) of the real working environment of coal miners, the dynamic inhalation exposure method was employed, and a control group and three coal dust groups (4, 10 and 25 mg/m3) were set up. Lung function was measured after 30, 60 and 90 days of coal dust exposure. Meanwhile, the serum, lung tissue and bronchoalveolar lavage fluid were collected after anesthesia for downstream experiments (histopathological analysis, RT-qPCR, ELISA, etc.). The results showed that coal dust exposure caused stunted growth, increased lung organ coefficient and decreased lung function in rats. The expression level of the M1 macrophage marker iNOS was significantly upregulated in the early stage of exposure and was accompanied by higher expression of the inflammatory cytokines TNF-α, IL-1β, IL-6 and the chemokines IL-8, CCL2 and CCL5, with the most significant trend of CCL5 mRNA in lung tissues. Expression of the M2 macrophage marker Arg1 was significantly upregulated in the mid to late stages of coal dust exposure and was accompanied by higher expression of the anti-inflammatory cytokines IL-10 and TGF-β. In conclusion, macrophage polarization and its molecular regulatory network (especially CCL5) play an important role in lung inflammation and fibrosis in SD rats exposed to coal dust by dynamic inhalation.

Solid Backfilling Efficiency Optimization in Coal Mining: Spatiotemporal Linkage Analysis and Case Study

In coal mining, solid backfilling technology is widely used. However, its efficiency is seriously hindered by the following two factors. Firstly, the process flow of the solid backfilling operation is more complicated in the back, and the spatiotemporal linkage (SPL) between actions of the cylinders powering each support and between hydraulic supports in the whole face lacks continuity. Secondly, the coal mining process in the front has a higher level of intelligence and technical maturity than the backfilling operation in the back, the latter permanently staying behind the former. To this end, the present study investigates the SPL of the mining and backfilling operations for single supports in the working and whole faces. The SPL of cylinder actions is analyzed for intelligent backfilling using hydraulic supports. We also investigate the SPL of the positions of each piece of key equipment involved in different steps of intelligent backfilling in the whole face. Formulas are derived for calculating the time required to complete the cyclic hydraulic support movement–discharge–filling operation for single supports and the whole face. The key factors influencing the time required to complete a hydraulic support movement–discharge–filling cycle are analyzed. On this basis, a backfilling efficiency optimization scheme is proposed. It envisages reducing the number of tampings and time gaps in actions of single supports and cylinders, increasing the number of hydraulic supports in parallel operation, and intelligent upgrading of the backfilling operation. These findings help synchronize coal mining and backfilling operations.

Моделирование гибких цепочек добавленной стоимости на основе «чистых» технологий переработки угля

The article discusses characteristics of the value chains that have developed in the Russian coal industry. It has been justified that the involvement of the coal industry in the value chain based on promising clean coal processing technologies is becoming a critical task in the context of the imposed sanctions and it is a real step towards new industrialization and transformation of the corner stone sector of the Russian fuel and energy complex. The author's approach to the study of the coal value chains is based on identifying the existing types of value chains in the coal industry, assessing their current resilience and modeling possible directions for upgrading the value chain to increase long-term resilience. A conclusion is made that, despite the currently emerging concept of the carbon-free energy development, the coal industry has all the necessary development prospects due to a differentiated approach to upgrading the value chains based on new flexible technologies and taking into account the specific features of individual companies. Such value chains can be formed at the existing coal mining operations, and in the future it will become possible to create various production facilities for environmentally friendly products based on already existing value chains.

Growth of Coal Mining Operations in the Elk River Valley (Canada) Linked to Increasing Solute Transport of Se, NO3-, and SO42- into the Transboundary Koocanusa Reservoir (USA-Canada).

Koocanusa Reservoir (KOC) is a waterbody that spans the United States (U.S.) and Canadian border. Increasing concentrations of total selenium (Se), nitrate + nitrite (NO3-, nitrite is insignificant or not present), and sulfate (SO42-) in KOC and downstream in the Kootenai River (Kootenay River in Canada) are tied to expanding coal mining operations in the Elk River Watershed, Canada. Using a paired watershed approach, trends in flow-normalized concentrations and loads were evaluated for Se, NO3-, and SO42- for the two largest tributaries, the Kootenay and Elk Rivers, Canada. Increases in concentration (SO42- 120%, Se 581%, NO3- 784%) and load (SO42- 129%, Se 443%, NO3- 697%) in the Elk River (1979-2022 for NO3-, 1984-2022 for Se and SO42-) are among the largest documented increases in the primary literature, while only a small magnitude increase in SO42- (7.7% concentration) and decreases in Se (-10%) and NO3- (-8.5%) were observed in the Kootenay River. Between 2009 and 2019, the Elk River contributed, on average, 29% of the combined flow, 95% of the Se, 76% of the NO3-, and 38% of the SO42- entering the reservoir from these two major tributaries. The largest increase in solute concentrations occurred during baseflows, indicating a change in solute transport and delivery dynamics in the Elk River Watershed, which may be attributable to altered landscapes from coal mining operations including altered groundwater flow paths and increased chemical weathering in waste rock dumps. More recently there is evidence of surface water treatment operations providing some reduction in concentrations during low flow times of year; however, these appear to have a limited effect on annual loads entering KOC. These findings imply that current mine water treatment, which is focused on surface waters, may not sufficiently reduce the influence of mine-waste-derived solutes in the Elk River to allow constituent concentrations in KOC to meet U.S. water-quality standards.

A novel in-depth intelligent evaluation approach for the gas drainage effect from point monitoring to surface to volume

Developing a comprehensive and intelligent evaluation approach for dynamic gas extraction parameters is especially important for the operation and management of gas drainage in coal mines. However, existing approaches lack an in-depth intelligent evaluation approach for acquiring surface parameters of gas flow and volume characteristic parameters of the entire drainage area from the finite monitoring data. To fill this gap, a novel Field-Zone-Network model as a unique approach were presented to overcome the above-mentioned challenges, with innovative multi-parameter solution and inversion models. It utilized advanced mathematical algorithms for parameter estimation of gas drainage, by integrating the finite monitoring points data of pipe network and physical characteristic parameters of pipe network and coal seam. The model's accuracy and reliability were validated through rigorous comparisons with field data collected from coal mines and numerical simulations conducted in simulated scenarios. It realized the sufficient mining of finite monitoring data from points (monitoring points) to surface (network) to volume (coal seam). Further, the newly comprehensive software was developed to enable real-time monitoring, analysis, and evaluation of gas drainage effect, providing valuable insights for optimizing extraction operations in coal mines. This research contributes to the advancement of gas drainage in coal mines by presenting a novel Field-Zone-Network model and comprehensive software, empowering efficient and intelligent gas extraction operations with enhanced monitoring and evaluation capabilities.

Assessment of soil properties in technogenically disturbed lands of Kemerovo Oblast – Kuzbass

Recultivation is a critical operation after mining operations. In Kemerovo Oblast – Kuzbass, Russia, a lot of land has suffered degradation due to stripping operations. The purpose of the study is to examine the technical, technological, and biological properties of lands technogenically disturbed as part of coal mining operations in Kuzbass. The object under study is soil and soil cover in the Talda coal mine at the experimental site and adjacent territories. The research goal is achieved through the following methods. The granulometric composition of soil is assessed using the areometric method. The structural-aggregate analysis is performed based on the distribution of aggregate content by size with a set of soil sieves. Water stability is established using the method of disintegration of soil aggregates under a layer of water up to 2 cm high for 10 minutes. The ecological condition of the soil is assessed based on its enzyme and biological activity. The conducted investigation reveals increased stoniness, hygroscopicity, and low humus content of soils on technogenically disturbed land plots. Technogenically disturbed lands are marked by more acidic and heavy metal-contaminated soils. No exceedances are detected for pesticides and radionuclides. The results demonstrate weak enzymatic (cellulolytic, catalase, dehydrogenase, urease, phosphatase, invertase, and soil respiration) and catalytic activity of the soils. All obtained results of assessment of soil conditions on the experimental site and adjacent territories should be used in planning further experimental work on conducting the biological recultivation phase to minimize random experimental errors associated with the influence of native vegetation cover and primary soil conditions on the survival of crops sown on the site.

Heavy metal(loid)s contamination and ecotoxicological hazards in coal, dust, and soil adjacent to coal mining operations, Northwest Pakistan

Heavy metal(loid)s (HM) are ascertained hazardous to the environment due to their toxic, bioaccumulative, and persistent nature. Coal, dust, and surrounding soil near coal mines (n = 21) in each specimen were examined for HM in the districts of Hangu and Kurram. Samples were investigated for HM using the atomic absorption spectrophotometer. Iron (Fe) exhibited the highest mean concentrations, whilst molybdenum (Mo) showed the lowest in the selected coal, dust, and soil specimens were 62,100 and 1.14, 52,610 and 0.9, and 45,300 and 2.0 mg/kg, respectively. HM in studied media was evaluated for ecotoxicological factors, namely contamination factor (CF), potential-ecological risk index (PERI), hazard index (HI), and cancer risk. CF values of dust were very-high and considerable due cadmium (Cd) in the districts of Hangu and Kurram, while that of soil were considerable in both districts. The ecological-risks (190 < PERI<380) were “considerable” due to dust and soil of the Hangu district, while the “moderate” ecological-risk (95 < PERI<190) was noted for the Kurram district. The HI values surpassed the limit of 1 for children due to soil and dust exposures. Higher HI values may pose chronic health risks to the locals. Among exposure routes, oral ingestion was noted as the primary pathway's. CR values were noted as less than the threshold set by the US EPA. This study recommended that HM contaminations be monitored periodically on a priority basis to develop strategies for combating the problem of health concerns.

Feasibility Evaluation of Highwall Mining in Open-Pit Coal Mine Based on Method of Integrated Analytic Hierarchy Process–Fuzzy Comprehensive Evaluation–Variable Weight Theory

Highwall mining is a method that involves using a continuous highwall miner system (CHM) to extract coal from the remaining coal seams, which has proven to be an effective and safe method for extracting coal after open-pit mining. However, application cases globally have shown that the feasibility of highwall mining in open-pit coal mines is subject to geological conditions, mining techniques, and other factors. If application conditions are not suitable, equipment may be trapped under collapsed coal–rock masses and unable to be retrieved, resulting in severe safety issues for slope stability. To meet the real-world demand for extracting the remaining coal in open-pit coal mines in China, it is urgent to conduct a feasibility evaluation of highwall mining in these areas. This paper establishes a mathematical evaluation framework for assessing the feasibility of highwall mining by summarizing a large number of engineering application cases globally and analyzing various technical characteristics such as geological deposit conditions, mining techniques, and technical equipment. The analytic hierarchy process (AHP), fuzzy comprehensive evaluation (FCE) and variable weight theory (VWT) are utilized in conjunction to form this framework, which includes four secondary indicators: geological deposit factors, mining technique factors, safety impact factors, and economic evaluation factors, and 20 tertiary sub-indicators, along with their corresponding characteristic values. The feasibility sub-set is divided into four categories: infeasible, basically feasible, relatively feasible, and highly feasible, and the values of the sub-indicators strictly follow and represent these four levels of feasibility. Weight vectors for the sub-indicators are obtained through a judgment matrix established within the mathematical evaluation framework. The fuzzy relationship matrix of the sub-indicators is constructed using fuzzy mathematical membership functions, and the final feasibility evaluation is determined through two-level comprehensive evaluation. The accuracy of the model is verified using the characteristic parameters of open-pit coal mines under two different conditions (JZT coal mine in Inner Mongolia, China, and GC coal mine in Australia). The results demonstrate that the maximum evaluation membership degree for the JZT mine is 0.7113, belonging to the “highly feasible” level, while the GC mine is 0.3304, belonging to the “basically feasible” level, which aligns well with real-world usage, proving that the evaluation model can effectively reveal the performance and membership degree of each indicator in different application cases. By quantitatively characterizing the feasibility level of highwall mining technology under different application conditions, this evaluation model can provide scientific guidance for coal mining enterprises to introduce CHM for highwall mining operation in open-pit coal mines.

Study on the Usefulness of Lean Management Tools and Techniques in Coal Mines in Poland

The article presents research on the possibilities of utilising the Lean Management method to increase the profitability of coal mining operations through cost rationalisation and production optimisation. The Lean Management method has its roots in the automotive industry, but its significant benefits can allow it to be transferred to other industries. Based on the analysis of global literature describing examples of its application in general mining, as well as the authors’ own observations related to Polish hard coal mining, it was determined that the Lean Management method is not being utilised in this field. This article outlines the course and results of an original expert-mathematical study to assess the usefulness of specific Lean Management tools and techniques in hard coal mining. The study drew on knowledge obtained from selected, competent experts who demonstrated high levels of agreement in their assessments. Five core production areas were identified, and twelve widely used Lean Management tools and techniques were selected. The obtained assessments of the usefulness of Lean tools could serve as valuable guidance for mining management in the selection of methods for improving mining production in coal mines.

Investigation on preventive inerting approach of coal spontaneous combustion in gob considering adsorption effect.

Coal spontaneous combustion in the gob poses a significant threat to coal mining operations. Designing optimal process parameters for nitrogen injection to prevent and control fires efficiently is crucial. To achieve this, a multi-field coupling equation was established, considering the adsorption of coal to gas. The model's accuracy was verified on-site, and the effects of nitrogen injection at different locations and flow rates were simulated. The optimal injection parameters were determined by analyzing temperature and inerting time. The results showed that the coal spontaneous combustion hazardous zone in the gob tested on-site was consistent with the simulation from the perspective of physisorption. Nitrogen injection had three stages: gas expansion, rapid oxygen dilution, and complete inerting. The nitrogen injection effect presented a nonlinear change in injection location and flow rate. The optimal nitrogen injection location for the Tingnan Coal Mine in Shaanxi was determined to be 90 m behind the working face on the inlet side, with an optimal flow rate of 800 m3/min. This study focused on gas adsorption and offered valuable insights for creating high-efficiency fire-fighting techniques that involve inserting in the gob.

A novel method for identification of disturbance from surface coal mining using all available Landsat data in the GEE platform

Coal mining has contributed to a solid and stable global economy. Surface mining and underground mining are the principal methods for extraction of coal worldwide and given the developments in mining technology and equipment, these methods are increasingly generating more and more coal. Surface mining is also a subject that cannot be overlooked in the context of sustainable development because amongst human activities it causes comparatively strong land disturbance. Much of the damage and assessment of land and ecosystems from surface mining occurs at the site, and at the regional scale; hence access to the mining data is limited. Moreover, it is difficult for remote sensing to extract information on larger-scale areas with high precision. As a consequence, a frequency index of open coal mining can be created by merging the vast high-resolution images acquired by Landsat sensors with the spectral properties of open coal scraped from the overburden layer. Such indices and morphological principles can be used to develop strategies for quickly identifying the open coal boundaries in a vast area without mine-related information. In addition, LandTrendr may be used to reconstruct the spatial and temporal processes of surface disturbance and remediation caused by regional surface coal mining to identify surface mining disturbance and reclamation. Seven typical mining locations worldwide were selected to test and confirm the proposed method's practicality and robustness, including delivering accurate findings based on randomly testing sample points and comparing the mature data outputs. The results showed that: (1) the overall accuracy of the open coal areas identified by the OCFI (Open Coal Frequency Index) was over 85 % (range 0.85–0.96). In all study areas, the accuracy of recognizing disturbance and reclamation events was greater than 76 %. (2) The surface mining disturbed 3046.42 km2 of land and 1487.39 km2 was reclaimed in the seven mining areas investigated between 1986 and 2018, resulting in a reclamation rate of 48.82 %. The proposed method is more accurate and faster in identifying open coal locations than the current commonly used land cover datasets based on comparisons with other data products. The approach can extract surface coal mining in the absence of mining data and offer precise boundary data for mining research, which can be extremely useful for extending mining operations.

Recollection and conservation of Vatica javanica subsp. scaphifolia, a critically endangered endemic tree species in Southeastern Borneo

Vatica javanica subsp. scaphifolia (Kosterm.) P.S.Ashton (Dipterocarpaceae) is an endemic tree confined to Southeastern Borneo. The International Union for Conservation of Nature (IUCN) Red List classifies the species as Critically Endangered (CR) based on the assessment conducted 25 years ago. The species is not collected yet in any ex-situ conservation areas in the world. After more than 3 decades since the last herbarium specimen was collected in 1991, here this study reported the recollection and new locations of V. javanica subsp. scaphifolia in Bukit Bangkirai Forest, Kutai Kartanegara Regency, East Kalimantan Province. The confirmation of the species involved a comparison between the newest collected specimens and living photos and the specimen type and key to the species in the protologue. The present research provides new information on the morphology of the tree species through photos of the wild living plants. Using an exploration survey method, this research recorded the population in two locations with elevation ranges of 70-95 m. The field survey located a total of 13 immature individuals with height and diameter ranges of 2.1-14.7 m and 1-9.7 cm, respectively. The study observed that forest conversion into rubber plantations (Hevea brasiliensis) and open coal mining are the main threats to the species. Conservation of the species has been done by collecting plant materials to serve as the first ex-situ living collection at the Bogor Botanic Gardens BRIN.

Дегазация сближенных угольных пластов направленной трассы скважинами

The technology of conducting degassing operations at the mines of Russia is determined by the experience of many years of using means of extracting methane from coal seams and worked-out spaces by drilling wells on coal seams under development, on converged layers, mainly under-worked, unloaded by a working face from rock pressure. The parameters of the degassing of methane release sources at the extraction areas of coal mines were determined based on the results of scientific studies of the processes of methane release into degassing wells and mine workings, methane content of coal seams, gas content of workings, extraction modes of captive methane-air mixtures, their gas composition, suitability for disposal. The dependences were established related to the methane content of coal seams on the yield of volatile substances, gas recovery indicators, and the rate of reduction of methane release during the operation of wells drilled in the plane of the coal seam at high-performance coal mines. The analysis of the results of the operation of coal mines in Russia was carried out, where the degree of methane extraction based on degassing and gas suction at mining sites was 760 m3/min or 54 % of all methane at 193 exploited sites. In 30 areas where degassing was used, this figure reached 1050 m3/min (75 % of the total). At the same time, the flow rate of captured methane was 365 m3/min, including 237 m3/min (60 %) at 6 mines. Studies of degassing parameters of the converged coal seams were carried out in mining areas where the development workings are separated from the mined-out space of the entire coal. In areas of mining operations with high methane release from undermined coal seams, a complex of underground degassing schemes was applied using long directional wells drilled from a local working with its horizontal part brought into the plane of the adjacent seam. The technology, performance and parameters of degassing are determined taking into account the mining conditions of occurrence and mining of coal seams, and the provisions of the regulatory instructions.

Influence of the natural content of mineral impurities and moisture on the manifestation of hazardous properties of coal seams

It is not possible to determine the type of coal in terms of reducibility from thermal decomposition without access to air for volatile maters to dry ash-free mass, which provides establishing the ratio between oxygen content and other essential components of organic mass. The hazards of coal mine operations depend to a large extent on the ratio of the main components, both in organic matter and in mineral impurities. Methods for determining the yield of volatile maters make it impossible to assess the effect of the main components of organic matter and mineral impurities on the hazard characteristics of coal seams. The volatile maters index reflects only the sum of the thermal decomposition gases: hydrogen, methane, carbon monoxide and carbon dioxide without considering the ratio between them. The determination of the hazard properties of a seam in relation to metamorphic transformations factor should include a case-by-case examination of the relationship between the major components of fuel both the organic and mineral, including the moisture content, for each coal seams.

Combination of GNSS technology and total station displacement monitoring of open pit mines

In our country, the surface mining industry currently holds a particularly significant position in the nation's industrialization and modernization process. Minerals exploited using open-cast mining technologies contribute significantly to the country's economy, including coal, copper, iron, bauxite, and more. However, deep coal mining operations often involve substantial bank heights, multiple geological faults, extensive rock layers, and the need for blasting. Some mines are situated in areas with weak ground conditions, resulting in significant ground subsidence, deformations, and open pits, posing a substantial safety risk to personnel, equipment, infrastructure, assets, and the surrounding environment. Therefore, monitoring the horizontal displacement of mine banks in the process of mining is highly necessary. Based on an analysis of the current mining practices, topographical and geological conditions at open-pit coal mines, this article proposes feasible solutions to enhance the effectiveness of monitoring and managing bank displacement at these mining sites.

In-situ gas contents of a multi-section coal seam in Sydney basin for coal and gas outburst management

The gas content is crucial for evaluating coal and gas outburst potential in underground coal mining. This study focuses on investigating the in-situ coal seam gas content and gas sorption capacity in a representative coal seam with multiple sections (A1, A2, and A3) in the Sydney basin, where the CO2 composition exceeds 90%. The fast direct desorption method and associated devices were described in detail and employed to measure the in-situ gas components (Q1, Q2, and Q3) of the coal seam. The results show that in-situ total gas content (QT) ranges from 9.48 m3/t for the A2 section to 14.80 m3/t for the A3 section, surpassing the Level 2 outburst threshold limit value, thereby necessitating gas drainage measures. Among the gas components, Q2 demonstrates the highest contribution to QT, ranging between 55% and 70%. Furthermore, high-pressure isothermal gas sorption experiments were conducted on coal samples from each seam section to explore their gas sorption capacity. The Langmuir model accurately characterizes CO2 sorption behavior, with fit coefficients (R2) greater than 0.99. Strong positive correlations are observed between in-situ gas content and Langmuir volume, as well as between residual gas content (Q3) and sorption hysteresis. Notably, the A3 seam section is proved to have a higher outburst propensity due to its higher Q1 and Q2 gas contents, lower sorption hysteresis, and reduced coal toughness f value. The insights derived from the study can contribute to the development of effective gas management strategies and enhance the safety and efficiency of coal mining operations.

Coal mine wastes: Effective mitigation of coal waste slurry and acid mine drainage through bioflocculation using mixotrophic bacteria as bioflocculants

Acid mine drainage (AMD) and coal waste slurry, byproducts of global mining and coal processing activities, represent significant environmental pollution concerns due to their acidic nature and high total suspended solids (TSS) content. The exploration of microbial treatment methods, specifically the utilization of microorganisms and their metabolic byproducts as bioflocculants, is underway to mitigate the adverse effects of these byproducts. This investigation assessed the effectiveness of 54 mixotrophic bacterial strains in treating coal waste slurry and AMD from coal mines located in Kalimantan, Indonesia. The bacterium Citrobacter freundii (strain SKC-4), cultured in SKC1 medium (comprising 225 mL of seawater from the Java Sea and 15 g/L molasses), demonstrated superior performance, reducing the TSS value from 4998.20 ppm to 16 ppm within an hour. Fourier Transform Infrared (FTIR) analysis revealed an increase in the intensity of the CO and CN groups from protein amides and CH2 from carbohydrates, suggesting an interaction between bacteria and clay minerals in the coal waste slurry. The bacteria also played a crucial role in adjusting the pH of AMD, elevating it from 3.82 to 6.07 after one hour of conditioning with a bacterial culture to AMD ratio of 1:9. The interaction between bacteria and their metabolic products was further substantiated by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis, which detected the presence of an extracellular polymeric substance (EPS). To our knowledge, this study represents the first exploration of the potential of mixotrophic bacteria as bioflocculants in the biotreatment of coal waste slurry and AMD from coal mining operations.

An integrated approach for quantifying trace metal sources in surface soils of a typical farmland in the three rivers plain, China

The presence of trace metals (TMs) in agricultural soil has garnered considerable attention due to their potential migration into crops, posing a significant risk to human health. In this study, we examined the concentrations of eight trace metals (Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the soil and investigated various soil physicochemical characteristics in the Three Rivers Plain region, China. The assessment of the geoaccumulation index (Igeo) for the mean concentration of all trace metals indicated that the soils were generally free from significant TM pollution. However, a noteworthy finding emerged in relation to Hg, where the maximum Igeo value suggested moderate pollution levels. Kriging prediction results further indicated that approximately 1.55% of the study area might be impacted by Hg pollution. Moreover, it is prudent to direct attention towards Cd, Cr, Cu, Mn, and Ni, as their Igeo values revealed that the region with the highest concentrations of these metals ranged from unpolluted to moderately polluted. This study employed a comprehensive approach, utilizing the Self-Organizing Map (SOM), Kriging spatial distribution, and the Positive Matrix Factorization (PMF) model to identify the sources of TMs in agricultural soil. The results unveiled that the primary contributors to TM presence were the natural parental materials, alongside industrial activities such as coal mining and coal plant operations, as well as agricultural practices. These findings provide foundational insights for future management strategies in the Three Rivers Plain, aiming to enhance agricultural productivity and promote sustainability.

Enhancing Supply Chain Resilience in Coal Mining: A Comprehensive Systematic Literature Review to Managing Disruptions

Supply chain risk and uncertainty are critical factors that impact coal mining operations. Risks can arise from various sources such as natural disasters, supplier disruptions, market fluctuations, regulatory changes, and geopolitical uncertainties (Marzouk et al., 2022; Pettersen-Sobczyk, 2018). Managing these risks involves identifying, assessing, and implementing measures to mitigate and minimize potential losses. Uncertainties, on the other hand, stem from the lack of predictability or knowledge about future events and outcomes. They represent a level of unpredictability and the potential for surprises or unexpected events that can impact the supply chain. Overcoming uncertainties requires a resilient supply chain capable of preparing for unexpected events, responding to disruptions, and recovering from them while maintaining operational continuity (Adobor, 2020; Gunasekaran et al., 2015). Resilience capability allows a company to restore its operations to their original or desired state after being disturbed (Chowdhury &amp; Quaddus, 2017). However, despite the abundance of literature proposing resilience frameworks in supply chain management, their application within the context of coal mining remains relatively limited (Agrawal &amp; Pingle, 2020; Belhadi et al., 2022). Existing research in the field of coal mining has primarily focused on operational efficiency, cost reduction, and production optimization, with limited attention given to the concept of resilience. Therefore, this research aims to address this gap by developing a comprehensive resilience framework specifically tailored to the mining supply chain, with a focus on coal mining company. By incorporating the unique characteristics and challenges of the mining industry, such as geological uncertainties, complex extraction processes, and environmental regulations, this framework will provide valuable insights and strategies for enhancing the resilience capabilities of coal mining company. Keywords: Supply chain resilience, Coal mining, Disruptioin, Risk mitigation, Systematic literature review

The Public Perception of the Existence of Coal Mines in South Kalimantan Province, Indonesia

Background and Objectives: The coal mining business is a source of foreign exchange for the country, but it is also thought to have a negative impact on the environment, therefore its continued existence can lead to a variety of public perceptions, both positive and negative. The purpose of this study is to ascertain public perceptions of the coal mining industry's existence and operational implications.&#x0D; Methods: The survey approach was used in this study to obtain information from respondents. Questions were posed using interviews, questionnaires, and secondary data.&#x0D; Results: The community leadership structure in the study area is that 35 respondents (48%) follow non-formal leadership, while 38 respondents (52%) follow formal leadership. Most community conflicts are usually triggered by land boundary disputes (38%), and complaints are not responded to (38%), and are resolved by consensus deliberation. Community responses to the impact of coal transportation are health problems (52%), the impact of the presence of coal mines is an increase in the economy (54%), disruption to public roads (66%), noise (66%), and air quality (72%). Coal hauling activities also have an impact on improving business prospects, namely 10% of respondents stated significant (high), 66% moderate, and 24% none. while for the criteria for increasing income, 16% of respondents stated an increase of 62%, a small increase, and 22% did not report. The environmental disturbance parameter stated that 60% of respondents felt disturbed and 40% did not. Environmental management activities on the impact of coal mining operations are 20% of respondents stating good, 34% abstaining and 22% not good.&#x0D; Conclusion: Community development and empowerment programs around the mine site must be implemented properly, and mine exploration permit holders must strictly adhere to the environmental impact analysis document and environmental management monitoring plan approved by the Ministry of Environment and Forestry.