Mining Research Articles

Agricultural wastes improve soil quality and enhance the phytoremediation efficiency of economic crops for heavy metal-contaminated soils in mining areas.

In recent years, global attention has increasingly focused on soil heavy metal (HM) contamination. However, there remains a paucity of studies examining the interaction effects of agricultural wastes as amendments in HMs contaminated soil, particularly concerning the utilization of economic crops for soil remediation. This study investigates the impacts of various agricultural wastes (soybean meal, peanut bran, oak leaves, and coffee grounds) on soil properties, plant growth, and HMs accumulation in economic crops (sugarcane and cassava) through pot experiments. The application of these amendments resulted in significant increases in soil pH, soil organic matter (SOM), and cation exchange capacity (CEC) content. Moreover, catalase and urease activities in sugarcane planting soil were enhanced by 2.73-32.53% and 84.07-132.74%, respectively, with differing effects observed in cassava planting soil. Applications of oak leaves and coffee grounds inhibited soil invertase activity (by 28.78-61.95%), whereas soybean meal and peanut bran stimulated invertase activity (by 28.18-122.05%). Overall, these amendments reduced the bioavailability of HMs in the soil, with soybean meal demonstrating the most significant reduction in the effective state HMs content in sugarcane planting soil. The pot experiment results demonstrated that soybean meal and peanut bran, as soil amendments, improved soil quality, and promoted the growth of sugarcane and cassava. Additionally, they also increased the accumulation amount of Cd, Pb, and Zn in the plants, thereby enhancing the effectiveness of phytoremediation in HM-contaminated soils. Consequently, this study provides practical insights for soil safety and cleaner production in HMs contaminated karst farmland.

Banana peel fermentation broth as a viable alternative carbon source for biological sulfate reduction in acid mine drainage

AbstractBACKGROUNDAcid mine drainage (AMD) is a major environmental threat in mining areas due to its strong acidity, high concentrations of sulfate, and heavy metals. Utilizing sulfate‐reducing bacteria (SRB) to reduce SO42− and remove heavy metals is a promising and economical AMD treatment. However, AMD lacks sufficient electron donors for sulfate reduction. Banana peel fermentation broth, containing various small‐molecule organic acids, is an effective alternative carbon source for SRB, promoting the use of agricultural waste in environmental remediation. This study aims to investigate the impact of adding banana peel fermentation broth to the bioreactor on pollutant removal performance and analyze its effect on the microbial community structure.RESULTSThe bioreactor utilising banana peel fermentation broth as an electron donor, demonstrated the effective removal of various pollutants, including sulfate (55.7%), Cu2+ (90.74%), Mn2+ (70.77%), Fe2+ (81.28%) and Cd2+ (100.00%), with an average reduction of 74.20% in chemical oxygen demand (COD). Sulfate reduction resulted in an increase in pH from 5.5 to 7.9. Microbial community structure analysis revealed that the primary genera involved in sulfate reduction were Desulfurispora and Desulfovibrio, while Delftia contributes to the immobilization of heavy metals. Additionally, the key genera responsible for fermentation to produce small molecule acids were Leptolinea and Sedimentibacter. In symbiosis with SRB, they play a crucial role in the removal efficiency of metals and sulfate.CONCLUSIONThe overall sulfate and heavy metals removal efficiency was found to be satisfactory after 30 days of continuous reactor operation. There was a notable increase in microbial abundance and community diversity within the reactor. Therefore, banana peel fermentation broth is a promising alternative organic carbon source in acid mine drainage(AMD) treatment. © 2025 Society of Chemical Industry (SCI).

Toxicity Assessment of River Sediments Impacted by Open-Pit Coal Mining in Colombia Using Caenorhabditis elegans

Coal mining is a critical economic for Colombia. However, mineral extraction is usually carried out near rivers that provide ecosystem services to riverside populations. Cesar River receives discharges from several open-pit coal mines, as well as from other anthropogenic sources. The aim of this work was to assess the chemical and the toxicity profile of the sediments from this river. Bottom sediment samples were collected from 12 points along the river, including tributaries and a Ramsar site, the Zapatosa Marsh. Trace elements were quantified employing ICP-MS, and mercury (Hg) was measured using a direct Hg analyzer. Aqueous extracts (K-medium) were obtained from dried sediments (1:3 ratio) and tested using Caenorhabditis elegans, assessing mortality, locomotion and growth as end points. Transcriptional effects associated with various toxicity mechanisms were evaluated using GFP-related transgenic strains (mtl-2, sod-4 and gst-1). Some trace metals enriched along the course of the river, especially Hg and V. Sediment extract-induced lethality was low (1.5–6.4%); however, nematode growth and locomotion decreased downstream the river, showing inhibition rates up to 23.3 and 35.4%, respectively. Extracts from downstream points increased the mRNA expression of tested genes compared to that elicited by the most upstream site, with greater values on stations receiving domestic sewage and mining outputs. Cobalt and lead were positively associated with metallothioneins and gst-1 expression. In short, coal mining areas should be closely monitored for trace-element release and their impact on biota. The Colombian government should implement laws and programs to protect key ecosystems from mining activities, as a commitment to sustainable development goals.

Effects of Soil Modification Materials on the Quality of Sandy Soil in Mine Dumps

Large-scale coal mine dumps are formed during the mining process of coal resources. These coal mine dumps comprise impoverished soil, posing significant challenges for vegetation restoration. To address this problem, soil microbial (EM) agents and fly ash have effectively improved soil quality. However, the effects of different application ratios on the quality of sandy soil in coal mine dumps are still unclear. This study aims to explore the applicable ratio for sandy soil in coal mine dumps. This study employed a field-based potted experiment design. A two-factor complete factorial experimental setup was utilized, with four levels of EM microbial agent to sandy soil weight ratio (0 g/kg, 0.1 g/kg, 0.2 g/kg, and 0.3 g/kg) and four levels of fly ash to sandy soil weight ratio (0 g/kg, 25 g/kg, 50 g/kg, and 75 g/kg), and the mixing of EM microbial agents and fly ash with the sandy soil was carried out at different ratios. Subsequently, the study examined the impacts of various dosages on the physicochemical properties of soil within the mine spoil heap, and a soil quality index was derived to quantify these effects. The application of EM microbial and fly ash resulted in significant improvements in the physicochemical properties of the soil compared to the control group. Notably, the combined application of EM microbial agent and fly ash exhibited superior effects on soil physicochemical properties compared to the individual applications of EM microbial agent or fly ash. Specifically, when the EM microbial agent concentration was 0.2 g/kg and the fly ash content was 75 g/kg, the enhancement in soil quality was most pronounced, with a soil quality index of 0.78. Mantel analysis revealed that the growth index and photosynthetic index of Corethrodendron fruticosum were primarily driven by soil total nitrogen and organic carbon. The research results can provide guidance and technical support for soil improvement in mining areas.

Elucidating the hydrochemistry and REE evolution of surface water and groundwater affected by acid mine drainage.

The impact of pyrite mining on water quality is a global concern. This study investigates the impact of acid mine drainage (AMD) from an abandoned pyrite mine in the Qinling Mountains on surface and groundwater hydrochemistry and rare earth elements (REEs) evolution. A total of 54 water samples were collected in 2021, of which the Muzi River downstream of the mining area was repeated three times in three sampling periods. Hydrogeochemical methods and stable isotope techniques were used to analyze the impacts of AMD. Results showed that tailing water in comparison to groundwater and surface waters exhibits low pH with high concentrations of SO42-, potentially toxic elements (PTEs), and REEs, and is characterized by normalized middle REE (MREE) enrichment. Groundwater is less influenced by AMD and shows HCO3-Ca and HCO3-Ca·Na types. AMD contaminates surface water to different degrees. Surface water received SO42- input from AMD, exhibited SO4-Ca, SO4·HCO3-Ca, and HCO3·SO4-Ca types within the mining area, and evolved from HCO3·SO4-Ca to HCO3-Ca downstream as AMD influence diminishes. High concentrations of PTEs and REEs are presented in AMD and seepage near the slag heap, and decreased rapidly along the flow path, while SO42- migrated over longer distances. The water in the study area primarily originates from atmospheric precipitation, with close relation among surface water, groundwater, and tailing water. Water-rock interactions and pyrite oxidation governed the hydrochemical composition, with sulfide oxidation facilitated the carbonatite-water reaction, which alleviated sulfide oxidation-induced acidification. The concentrations of PTEs are regulated by adsorption and precipitation, carbonate buffering, and dilution along the flow path. REEs are mainly controlled by pH, inorganic complexation, and secondary mineral adsorption. As the pH changes from acidic to neutral or weakly alkaline, REEs shift from sulfate-complex dominated to carbonate-complex dominated. These insights contribute to a better understanding of AMD impacts on surface and groundwater, providing a basis for the rational management of AMD.

Zn2+ adsorption in ferric-silicates microstructures in sulfidic tailings mediated through mineral weathering by Acidithiobacillus species.

Heavy metals released from metallic sulfidic tailings pose significant environmental threats by contaminating surface and groundwater in mining areas. Sustainable rehabilitation methods are essential to remove or stabilize these metals, improving the quality of acid mine drainage and minimizing pollution. This study examines the adsorption capacity of zinc ions (Zn2+) by different iron-silicate mineral groups under natural weathering and bacteria-regulated weathered conditions. Batch experiments revealed that all tested mineral groups exhibit limited adsorption Zn2+ on iron-silicate surfaces, with adsorption behavior aligning with Langmuir and Freundlich isotherm models. Among the mineral groups, pristine iron-muscovite (2.58 mg/g) and iron-chlorite (4.52 mg/g) demonstrated the highest Zn2+adsorption capacity, primarily due to favorable ion exchange properties and surface characteristics. Acidic conditions induced by pyrite oxidation and the experimental growth medium slightly reduced Zn2+ adsorption in samples without microbial inoculation. In contrast, the addition of Acidithiobacillus species modestly enhanced Zn2+ adsorption, likely through microbial alteration of silicate surface properties and the formation of secondary iron-silicate aggregates with high adsorption potential. The dominant adsorption mechanisms included electrostatic attractions, surface complexation and coprecipitation. It is recommended to elevate pH levels and thus enhance metal ion adsorption through the incorporation of alkaline additives such as zeolites or bauxite residue to optimize Zn2+ immobilization in sulfidic tailings. This study highlights the importance of both microbial and clay mineral selection in designing effective strategies for stabilizing Zn2+ in metallic sulfidic tailings.

Utilizing municipal solid waste incineration fly ash for mine goaf filling: Preparation, optimization, and heavy metal leaching study.

Municipal solid waste incineration fly ash (MSWI FA) contains many harmful substances, such as heavy metals, which pose a great threat to the ecological environment. Its proper disposal is an urgent environmental problem that needs to be addressed. The large number of goaf areas in China's mines provides a new approach for MSWI FA treatment. Scientifically processed MSWI FA can be used for goaf filling; this reduces the stockpile of MSWI FA and improves the safety of mine goaf areas. In this study, paste backfill was prepared using MSWI FA and slag as cementitious materials and coal gangue as aggregates under the composite excitation of sodium hydroxide and water glass. The optimal mix ratio was determined using response surface methodology, and the leaching trend of the heavy metal ions inside the material and the micro mechanism of strength formation were studied. Molecular dynamics simulations were used to further examine the leaching pathways of the heavy metal ions. The experimental research showed that the optimal mix proportions of the backfill were 81.65%, 3.67% and 52.27% for the mass concentration, aggregate-to-cement ratio and fine gangue ratio, respectively. The main polymerization products were C-(A)-S-H and N-A-S-H silicate gel, and small amounts of ettringite (AFt), calcium aluminate chloride (3CaO • Al2O3 • 3CaCl2 • 30H2O) and CaCO3 were generated. Through Materials Studio (MS) software, the leaching pathway of the heavy metal ions in the backfill and the adsorption performance between the ions were examined, and the influence of the C-A-S-H gel on the leaching rates of the heavy metal ions of Pb2+, Cr3+, and Cd2+ was explored. The leaching rate was ranked as Pb2+>Cr3+>Cd2+. In this study, a pollution-free and structurally stable mine paste backfill material was prepared using MSWI FA solid waste.

An Advanced Approach for Geometallurgical Modeling Applied to Bauxite Mines

Geometallurgy is an approach that integrates geology, mining, processing, and environmental areas, aiming to increase knowledge of the deposit and reduce risks in mining projects and/or operations. Growing changes in economic and operational scenarios require the development of robust models for metallurgical responses. Typically, the population of geometallurgical variables is small, and there are restrictions on applying geostatistical techniques, such as Ordinary Kriging, since recoveries are considered non-additive variables. This study used multiple linear regression to develop a geometallurgical model for a bauxite mine. The developed models enabled reconciliation with real results, and this application for bauxite mining represents a novelty in the literature. The model estimated the mass recovery in the coarse fraction with an accuracy greater than 97%. Additionally, the geometallurgical model developed for Mineração Rio do Norte (MRN) allows predictability and mapping potential product quality deviations.

Hydrothermal alteration and mineral potential zones of Bauchi area Northeastern Nigeria using interpretation of aeroradiometric data

This research focuses on hydrothermal alteration and mineral potential zones of the Bauchi area in northeastern Nigeria using the interpretation of aeroradiometric data. The high resolution aeroradiometric data were acquired and analyzed for possible areas of mineral potentials, lithologic units, and hydrothermal alteration. The radiometric data were interpreted by minimum curvature gridding techniques, arranged in three different grids as radioelement of percentage potassium (%K), equivalent thorium (eTh), and equivalent uranium (eU), and were displayed as pseudo[1]coloured images to reveal the surface concentration of each of the radioelements. The radioelement maps, K/eTh ratio map, and ternary image were used to recognize and interpret the radiometric signatures for mineral potential zones, lithological units, and identification of hydrothermal alteration zones in the study area. The relatively high eTh concentration (32.1274-54.8017 ppm) could be attributed to granitic rocks and high K/eTh ratio (0.285718-0.422418 wt%/ppm) indicates hydrothermally altered areas. The regions with high %K, high eTh and high eU coincide with the granitic rocks and this indicates that hydrothermal alteration and mineral potential zones are predominance in older granites and younger granites. The hydrothermal alteration zones are favorable areas for mineralization as observed from the K/eTh ratio map. The hydrothermally altered areas are underlain by granitic rocks and this attests that the hydrothermal alteration process is accompanied by granitic intrusions and emplacement of late intrusive rocks which provide the heat sources for hydrothermal solutions along fractures for the formation of minerals or react with the enclosing rock for hydrothermal alteration and subsequent mineralization.

In situ purification of ammonium nitrogen wastewater in rare earth mine by native bacteria isolating from original mining area

Ammonium sulfate ((NH4)2SO4) leaching method to extract rare earth elements (REEs) of mine has produced a large amount of NH4+-N-enriched wastewater derived from ore body, leading to many serious environmental pollution problems. This study was the first time to establish an in-situ treatment for real REEs wastewater outside and inside the ore body by an isolated indigenous microorganism. The results stated that Citrobacter sp. X-9 achieved the highest NH4+-N removal efficiency among the isolated six microbial strains. Moreover, the microbe to treat the REEs wastewater outside ore body gave the greatest NH4+-N removal efficiency under the optimized conditions in the Erlenmeyer flask (250-mL) and bioreactor (10-L). Furthermore, compared to the others’ modes, the in-situ treatment by cyclic mode with Citrobacter sp. X-9 possessed superior performance in NH4+-N removal efficiency for wastewater inside of ore body, showing that the established in-situ treatment was the potential approach for REEs wastewater purification.

Individual Tree Segmentation Using Deep Learning and Climbing Algorithm: A Method for Achieving High-precision Single-tree Segmentation in High-density Forests under Complex Environments

Accurate individual tree segmentation, which is important for forestry investigation, is still a difficult and challenging task. In this study, we developed a climbing algorithm and combined it with a deep learning model to extract forests and achieve individual tree segmentation using lidar point clouds. We tested the algorithm on mixed forests within complex environments scanned by unmanned aircraft system lidar in ecological restoration mining areas along the Yangtze River of China. Quantitative assessments of the segmentation results showed that the forest extraction achieved a kappa coefficient of 0.88, and the individual tree segmentation results achieved F-scores ranging from 0.86 to 1. The climbing algorithm successfully reduced false positives and false negatives with the increased crown overlapping and outperformed the widely used top-down region-growing point cloud segmentation method. The results indicate that the climbing algorithm proposed in this study will help solve the overlapped crown problem of tree segmentation under complex environments.

Sedimentological and mineral control on metal(oid) distribution in sediments along the source (base rock, mining waste)‒pathway (stream sediment)‒receptor (floodplain sediment) chain in a catchment impacted by historical mining: a case study from the Baiut Mining Area, Romania

Sedimentological and mineral control on metal(oid) distribution in sediments along the source (base rock, mining waste)‒pathway (stream sediment)‒receptor (floodplain sediment) chain in a catchment impacted by historical mining: a case study from the Baiut Mining Area, Romania

With coal forever? Conflicted attitudes of residents in coal mining areas in the Czech Republic, Germany and Poland to coal phase-out

With coal forever? Conflicted attitudes of residents in coal mining areas in the Czech Republic, Germany and Poland to coal phase-out

Monitoring and evaluation of ecological restoration in open-pit coal mine using remote sensing data based on a OM-RSEI model

ABSTRACT Open-pit coal mining poses a severe threat to regional ecological security. Rapid and accurate monitoring of ecological quality changes is crucial for regional ecological restoration. In this study, taking the Wujiata open-pit coal mine as an example, the Red-Edge Normalized Difference Vegetation Index (RENDVI), Salinity Index (SI-T), WETness index (WET), Normalized Differential Built Soil Index (NDBSI), Land Surface Temperature (LST), and Desertification Index (DI) were used to construct the Open-pit Mine Remote Sensing Ecological Index (OM-RSEI) through Principal Component Analysis (PCA). The ecological quality and restoration conditions of typical mining areas in arid and semi-arid regions were monitored and evaluated. The results shown that: (1) The contribution rates and eigenvalues of OM-RSEI were higher than those of conventional RSEI, OM-RSEI was more applicable in open-pit mining areas. (2) From 2018 to 2023, the OM-RSEI of the Wujiata open-pit coal mine showed a ‘V’ shaped fluctuation that was damaged and then gradually recovered. (3) The degraded area of Wujiata open-pit coal mine and its 5 km buffer zone accounted for 78.02%, and the improved area accounted for 19.16%. (4) The average Moran’s I index of OM-RSEI in the study area was 0.8189, and the high–high clustering corresponded to the ‘good’ and ‘excellent’ distributions, while the low–low clustering corresponded to the ‘poor’ and ‘less-poor’ distributions. The OM-RSEI provided a new indicator for monitoring and evaluation of ecological restoration in open-pit coal mines, which can provide theoretical support for ecological restoration in open-pit coal mining areas.

Synergistic ecological remediation of tailings in high altitude ecologically fragile areas by ryegrass (Lolium perenne L.) and activated carbon

The ecological vulnerability and extreme physicochemical properties of tailings in high-altitude mining areas pose challenges to the ecological restoration of tailings. Therefore, the aims of the current study were to remediate tailings in high-altitude mining areas by combining ryegrass (Lolium perenne L.) and activated carbon. Ryegrass potting experiments with Cu and Pb–Zn tailings and the two tailings amended with activated carbon. The effects of synergistic treatment of ryegrass and activated carbon on the physicochemical properties, heavy metal content, and enzyme activity of Cu tailings and Pb–Zn tailings were studied. Compared with planting ryegrass group, activated carbon significantly improved the water holding capacity of the two tailings. After restoration, the water holding capacity of Cu tailings and Pb–Zn tailings were 47.33% and 47.67%, respectively. In addition, the combination of ryegrass and activated carbon improved the quality of tailings, effectively increasing the organic carbon and available phosphorus content of tailings. Ryegrass and activated carbon synergistically activate tailings enzyme activity. The decrease in heavy metals in the tailings was mainly attributed to uptake by ryegrass rather than immobilization by activated carbon. The synergistic remediation of ryegrass and activated carbon is a potential ecological restoration treatment for tailings in high-altitude ecologically fragile areas.

Assessment of surface water quality in mining area: A case study of the southwest region of Burkina Faso

Mining activities, whether industrial or artisanal, are often responsible for the pollution of water resources, leading to significant degradation of water quality. This study aims to assess the quality of surface waters in three out of the four provinces of the South-Western region of Burkina Faso, an area known for its numerous mining sites. To evaluate the water quality in the study area and to assess the importance of each parameter in influencing this quality, we applied Weighted Arithmetic Water Quality Indices (WAWQI) and Hierarchical Cluster Analysis. These analyses were based on data obtained from the measurement of various physicochemical parameters (pH, electrical conductivity, total hardness, calcium, magnesium, sodium, potassium, bicarbonate, chloride, sulphate, nitrate, phosphate) and heavy metals (total iron, manganese, lead, cadmium, chromium, copper, zinc, arsenic) collected at the end of 2020. Samples were taken from a variety of sources: four rivers and five reservoirs. This approach provided a comprehensive assessment of the surface water quality in the study area. The results indicated that, of the twenty parameters analysed, only total iron consistently exceeded the World Health Organization (WHO) standards across all samples, while bicarbonate exceeded the standard in three instances and calcium-phosphate in one. The water quality index values ranged from 8.18 to 165.85, with an average of 46.84. Only one river sampling point, situated at the Poni province (SW4 at Poniro River), exhibited "poor" water quality, while all other water bodies exhibited water quality ranging from "good" to "excellent." The dendrogram analysis confirmed this finding by showing that total iron is separated from the other parameters, highlighting its negative role in the deterioration of water quality, whereas the other parameters play a positive role.

Effect of alluvial thickness on the surface subsidence characteristics at deeply buried mining area with thin bedrock: A case study

Effect of alluvial thickness on the surface subsidence characteristics at deeply buried mining area with thin bedrock: A case study

Controls on the Distribution of Potentially Toxic Elements Between the River Sediment and Its Porewater Near the REE Mining Area, SW China

ABSTRACT Potentially toxic elements (PTEs) from tailings migrate into sediments, causing environmental contamination, but limited understanding of secondary PTEs migration mechanisms post-deposition hinders predictions of their environmental fate. The aquatic environment of China’s Maoniuping rare earth deposit (second-largest REE mine) exhibits complex oxic-anoxic conditions, ideal for studying PTEs distribution at water-sediment interfaces. By analyzing five sediment-porewater profiles, this study identifies key mechanisms: (1) Physicochemical fluctuations combined with rapid flow through coarse sediments enhance PTEs mobility, threatening downstream ecosystems; (2) Reducing conditions in S2/S5 sediment profiles triggered Fe/Mn release, elevating porewater PTEs; (3) Alkaline reducing environments reduce As(VI) to mobile As(III), posing long-term risks to aquatic flora; (4) Distribution characteristics and correlation analysis of sediment profiles revealed that Fe, Mn, Zn, Cd, and Cr exhibited consistent patterns, suggesting that PTEs adsorption on Fe and Mn oxides primarily controls their mobility. This study underscores the significance of PTEs redistribution at the water-sediment interface in mining regions. Understanding these processes is crucial for developing effective environmental management strategies and mitigating associated environmental risks.

Mechanical properties and piecewise constitutive model of fine sandstone in mining area of western China

Owing to the differences in sedimentary environments in the mining areas of western China, the mechanical properties of rocks in this region are significantly different from those in the central and eastern regions. Therefore, uniaxial cyclic loading-unloading tests were conducted on fine sandstone found in many roof rocks to study the evolution laws of mechanical properties, deformation characteristics, acoustic emission (AE) parameters, and energy under cyclic loading and unloading conditions. The accumulated residual strain, dissipative energy, acoustic emission cumulative ringing counts, and cumulative energy were introduced to characterize the degree of rock damage. Based on this, a piecewise constitutive model was established for fine sandstone. The results indicate that (1) the cumulative ringing counts and cumulative energy of the AE increase in a stepwise manner with an increase in the cyclic loading and unloading times. Still, there is a sudden increase in the plastic failure and post-peak failure stages. (2) The fine sandstone specimens’ input energy, elastic energy, and dissipative energy density increased nonlinearly during the cyclic loading tests. Owing to the closure of the primary pores in the microfracture compaction stage, dominant matrix deformation in the elastic deformation stage, and development and expansion of cracks in the plastic failure stage, with an increase in the cyclic loading and unloading times, the dissipative energy ratio first decreased and then increased. (3) Based on the tangential modulus, residual strain, and Felicity ratio, fine sandstone’s cyclic loading and unloading stress-strain curves were divided into microfracture compaction, elastic deformation, and plastic failure stages. The piecewise constitutive model of fine sandstone constructed with accumulated AE energy was the closest to the real stress-strain curve of the rock, and the deviations of the peak stress and peak strain from the actual situation were 0.52% and 0.84%, respectively. The research results can provide theoretical support for identifying the degree of rock damage in western mining areas and ensure the safe and efficient development of coal resources.

Study on subsidence evolution induced by coal mining under highway based on finite element simulation

Accurate estimation of overlying strata subsidence and surface deformation caused by coal extraction is crucial for assessing the impact of mining activities on surface infrastructure. In this study, we investigated the subsidence evolution of overlying strata and ground surface induced by underground mining using finite element simulation and focus on a mining district in the Yu-Heng mining area of the central Ordos Basin and then, the influence of underground longwall mining on the surface roads was evaluated. A three-dimensional geological model of the mining district was constructed, considering the actual stratum structures and the deterioration effect of water on rock mechanical properties. The whole coal mining process was simulated to predict the evolution of the subsidence basin at different mining stages, and the surface deformation characteristics caused by coal mining were calculated. Results showed that the subsidence characteristics by numerical simulation were highly consistent with the records of surface subsidence in the adjacent areas, indicating that the constructed geological model can accurately reflect the actual geological conditions and the deformation behaviors of overlying strata. A comparative study revealed that the mechanical properties of the generalized layers determined by processing the mechanical parameters of dry core samples will be much higher than those of the natural strata under the in situ water-saturated condition, and then the subsidence caused by coal mining will be significantly underestimated. Thus, the water-induced mechanical property deterioration of overlying strata must be fully considered when constructing geological models.