Comparison of Antimony Sources and Hydrogeochemical Processes in Shallow and Deep Groundwater Near the Xikuangshan Mine,Hunan Province,China

Antimony pollution in the groundwater of the Xikuangshan (XKS) antimony (Sb) mine area in China’s Hunan Province has attracted increasing attention. A total of 43 water samples were collected to help understand the hydrogeochemical characteristics, identify the Sb source, and evaluate the water–rock interactions of the Shetianqiao aquifer (SA). The Sb concentrations in shallow and deep SA water samples were 0.1–47.4 mg L^?1 and 0.3–19.2 mg L^?1, respectively. Stibnite oxidation and leaching from arsenic alkali residue mine wastes were the main Sb sources for the shallow SA water, whereas stibnite oxidation and stronger water–rock interaction were the predominant Sb sources for the deep SA water. The higher Sb concentration (>?10.0 mg L^?1) in shallow SA water was predominantly induced by weathering of Sb-bearing minerals, evaporation/concentration effects, and cation exchange, whereas the higher Sb concentration in deep SA water was largely caused by weathering of Sb-bearing minerals, evaporation/concentration effects, ion exchange, and competitive adsorption. These findings provide a more detailed understanding of the geochemical behavior of Sb in groundwater and can be used to develop suitable Sb pollution management strategies.

     

Groundwater Geochemical Variation and Controls in Coal Seams and Overlying Strata in the Shennan Mining Area,Shaanxi, China

Water resource conservation and ecological protection are key coal mining issues in northern Shaanxi Province and the Yellow River Basin. Revealing the characteristics and variation patterns of groundwater quality in the coal series and its overlying aquifers can provide a geological foundation for solving or optimizing these issues. Taking the Zhangjiamao coal mine of the Shennan mining area in northern Shaanxi Province, western China, as an example, water samples were collected for analysis from the: quaternary strata, weathered bedrock, burnt rock, coal series, and coal seam. Test parameters included conventional ion concentrations, total dissolved solids (TDS), and pH. Key water chemistry indicators such as oxidation/reduction index (ORI) and groundwater chemical closure index (GCCI) were used to explain the water quality differences. The Quaternary water, burnt rock water, and weathered bedrock water were dominantly the Ca–HCO₃ type, the coal series water (Yan’an Formation) was dominantly Ca–HCO₃ and Na–Cl types, and the coal seam water was dominantly Na–Cl type. From the shallow groundwater to coal seam water, dissolution and leaching gradually decrease and degree of retention gradually increases. Coal seam water was characterized by high TDS, high GCCI, and low ORI, reflecting a closed hydrogeochemical environment and moderate sulfate reduction. Leaching, salt accumulation, sulfate reduction, and cation exchange jointly control the groundwater chemical characteristics and evolution of the coal series and its overlying aquifers. Salt accumulation and cation exchange reactions of the stagnant coal seam water in the arid and semiarid climates and shallow buried conditions result in increased mineralization; the water quality is vastly different from that of the overlying aquifers, which are dominated by leaching. Groundwater circulation in the coal series and coal seam are of the infiltration–retention type, and the overlying aquifer of the coal series are of the infiltration–runoff type. A comprehensive hydrogeological model was constructed of the Middle Jurassic coal series and its overlying aquifers in the area. The results of this study have implications for the identification of mine water influx sources in the Shennan mining area, and the understanding of controls on the groundwater geochemical variation in Jurassic coal field of western China.

     

Alkalinity generation and metals retention in a successive alkalinity producing system

Alkalinity generation and metals retention were evaluated during the initial year of operation of a treatment wetland, consisting of four 185 m² inseries cells comprised of alternating vertical-flow anaerobic substrate wetlands (VFs) and surface-flow aerobic settling ponds (SFs). The substrate in the VFs consists of spent mushroom substrate (SMS) and limestone gravel, supplemented with hydrated fly ash in a 20∶10∶1 ratio by volume. Approximately 15±4 L/min of acid mine drainage (AMD) from an abandoned underground coal mine in southeastern Oklahoma, USA, was directed to the system in October 1998 (mean influent water quality: 660 mg L⁻¹ net acidity as CaCO₃ eq., pH 3.4, 215 mg L⁻¹ total Fe, 36 mg L⁻¹ Al, 14 mg L⁻¹ Mn, and 1000 mg L⁻¹ SO₄ ⁻²). Flow through the first VF resulted in substantial increases in alkalinity, decreased metal concentrations and circumneutral pH. 258±84 mg L⁻¹ of alkalinity was produced in the first VF by a combination of processes. Final discharge waters were net alkaline on all sampling dates (mean net alkalinity=136 mg L⁻¹). Total Fe and Al concentrations decreased significantly from 216±45 to 44±28 mg L⁻¹ and 36±6.9 to 1.29±4.4 mg L⁻¹, respectively. Manganese concentrations did not change significantly in the first two cells, but decreased significantly in the second two cells. Mean acidity removal rates in the first VF (51 g m⁻² day⁻¹) were similar to those previously reported.     

Hydrogeochemistry,Elemental Flux,and Quality Assessment of Mine Water in the Pootkee-Balihari Mining Area,Jharia Coalfield,India

Ninety nine mine water discharge samples were collected and analyzed for pH, electrical conductivity (EC), major cations, anions, and trace metals in the Pootkee-Balihari coal mining area of the Jharia coalfield. The mines of the area annually discharge 34.80 × 10⁶ m³ of mine water and 39,099 t of solute loads. The pH of the analyzed mine waters ranged from 6.97 to 8.62. EC values ranged from 711 μS cm⁻¹ to 1862 μS cm⁻¹, and reflect variations in lithology, geochemical processes, and hydrological regimes in the mines. The cation and anion chemistry indicate the general ionic abundance as: Mg²⁺ > Ca²⁺ > Na⁺ > K⁺ and HCO₃ ⁻ > SO₄ ²⁻ > Cl⁻ > NO₃ ⁻ > F⁻, respectively. Elevated SO₄ ²⁻ concentrations in the Gopalichuck, Kendwadih, and Kachhi-Balihari mine waters are attributed to pyrite weathering. The water quality assessment indicated that TDS, hardness, Mg²⁺, and SO₄ ²⁻ are the major parameters of concern in the study area. Except for Fe, all of the measured metals in the mine water were well within the levels recommended for drinking water. With only a few exceptions, the mine water is of good to permissible quality and suitable for irrigation.     

Geochemistry,Hydraulic Connectivity and Quality Appraisal of Multilayered Groundwater in the Hongdunzi Coal Mine,Northwest China

This study assessed the geochemistry and quality of groundwater in the Hongdunzi coal mining area in northwest China and investigated the mechanisms governing its hydrogeochemistry and the hydraulic connectivity between adjacent aquifers. Thirty-four groundwater samples were collected for physicochemical analyses and bivariate analyses were used to investigate groundwater quality evolution. The groundwater in the mine was determined to be neutral to slightly alkaline, with high levels of salinity and hardness; most samples were of SO₄·Cl–Na type. Fluoride and nitrate pollution in the confined aquifers were identified, primarily sourced from coals. Natural geochemical processes, such as mineral dissolution, cation exchange, and groundwater evaporation, largely control groundwater chemistry. Anthropogenic inputs from agricultural and mining activities were also identified in both shallow unconfined aquifers and the deeper confined aquifers, respectively. It was determined that the middle confined aquifer has a high hydraulic connectivity with the lower coal-bearing aquifer due to developed fractures. Careful management of the overlying aquifers is required to avoid mine water inrush geohazards and groundwater quality deterioration. The groundwater in the mining area is generally of poor quality, and is unsuitable for direct human consumption or irrigation. Na⁺, SO₄^2?, Cl^?, F^?, TH, TDS, NO₃^?, and COD_Mn are the major factors responsible for the poor quality of the phreatic water, while Na⁺, SO₄^2?, F^?, and TDS are the major constituents affecting the confined groundwater quality. This study is beneficial for understanding the impacts of coal mine development on groundwater quality, and safeguarding sustainable mining in arid areas.     

Quality Assessment of Mine Water in the Raniganj Coalfield Area,India

In a qualitative assessment of mine water from the Raniganj coalfield, 77 mine water samples were analyzed to assess water quality and suitability for domestic, industrial, and irrigation uses. The pH of the mine water ranged from 6.5 to 8.8. Total dissolved solids (TDS) ranged from 171 to 1,626 mg L⁻¹; spatial differences between the TDS values reflect variations in lithology, activities, and prevailing hydrological regime. The anion chemistry was dominated by HCO₃ ⁻ and SO₄ ²⁻. On average, Cl⁻ contributes 10 and 19% of the total anionic balance, respectively, in the Barakar and Raniganj Formation mine water. F⁻ and NO₃ ⁻ contribute <2% to the total anions. The cation chemistry is dominated by Mg²⁺ and Ca²⁺ in the mine water of the Barakar Formation and Na⁺ in the Raniganj Formation mines. Much of the mine water, especially of the Barakar Formation area, has high TDS, total hardness, and SO₄ concentrations. Concentrations of some trace metals (i.e. Fe, Cr, Ni) were found to be above the levels recommended for drinking water. However, the mine water can be used for irrigation, except at some sites, especially in the Raniganj Formation area, where high salinity, sodium adsorption ratio, %Na, residual sodium carbonate, and excess Mg restrict its suitability for agricultural uses.     

Acid Mine Drainage at the Abandoned Kettara Mine (Morocco): 2. Mine Waste Geochemical Behavior

Weathering and humidity cell tests were used to predict the potential for acid mine drainage (AMD) and to estimate the mineral reaction rates and depletion of fine and coarse tailings from the abandoned Kettara mine, Morocco. The geochemistry of the fine and coarse mine wastes was similar and, as expected by static tests, the wastes produced significant amounts of AMD. The sulfate production rate of both fine and coarse tailings was very high (2,000–8,000 and 2,400–560 mg SO₄/kg/week, respectively) during the first weeks of kinetics tests. After 9 weeks, sulfate release became low, ranging between 600 and 78 mg SO₄/kg/week for fine tailings and 500–120 mg SO₄/kg/week for coarse tailings. Effluent water samples had low pH (2.9–4.2) and elevated concentrations of acidity, sulfate, iron, copper, and zinc. Most or all of the dissolved K, Na, Al, Mg, and Si in the AMD result from the acidic dissolution of silicates (chlorite, talc, muscovite, and albite). Fine tailings produce much higher concentrations of acidity and sulfate than coarse tailings. However, due to greater transport of oxygen and water within the coarse waste, coarse tailings could be of greater environmental significance than fine tailings. The coarse waste continued to release acid after 378 days of leaching, whereas the fine tailings naturally passivates. These laboratory results agree with field observations; the upper profile of the coarse waste rock dam is highly oxidized (75 cm) whereas oxidation in the fine tailings does not extend more than 5–15 cm beneath the surface. A comparison between weathering and humidity cell tests indicated that the general trend of dissolution of metals was essentially similar for both methods. However, sulfate depletion rates were higher for the weathering cell tests. These tests indicate that the Kettara tailings piles and dam will continue to release acid for a long time unless remedial action is taken.     

Impact of lead/zinc ore mining on groundwater quality in Trzebionka mine (southern Poland)

The intensive mining activity carried out by “Trzebionka” zinc-lead mine causes changes in the hydrodynamic regime of the triassic aquifer as well as essential changes in the chemical composition of the groundwater. The mine water, in comparison with groundwaters collected directly from fractures and Karstic channels and with groundwaters pumped out from wells situated in Chrzanow region, is characterized by higher contents of almost all major dissolved constituents as, well as, many trace elements. Hydrogeochemical background of triassic carbonate series aquifer has been elaborated. Largest anomalies in extent of almost all elements have occurred in area of the “Trzebionka” mine. In this water general trend of increase of pH, total dissolved solids and SO₄ ²⁻ concentration with simultaneous trends of decrease of Zn²⁺ and Pb²⁺ concentrations have been noticed. Water pumped out from the mine in spite of its low quality, is utilized in about 80% as potable water after undergoing complicated treatment.     

Predicting Groundwater Rebound in the South Yorkshire Coalfield,UK

Abstract:  The semi-distributed model GRAM (groundwater rebound in abandoned mineworkings) has been applied to part of the South Yorkshire Coalfield, UK, to predict the pattern of groundwater rebound, in particular the timing and rates of changes in mine water flows between abandoned collieries. The model is based upon the mining hydrogeologist's concept of ‘ponds’ (discrete volumes of interconnected workings) and calculates water balances over time for all ponds in a multi-pond mined system. GRAM was successfully calibrated against observed groundwater levels over a 5 year period from 2001 to 2005 before being used to predict future rates of groundwater rebound, in accordance with different scenarios, including average, low, and high rainfall scenarios. The results reveal that it could take up to 22 years before an inflow of water occurs into the last remaining colliery in the area at Maltby, with the first surface discharge expected in approximately 15 years time from an old mine shaft. If Maltby is closed and pumping ceases across the area, then it could be 100 years before groundwater rebound is complete.     

Explanation for peat-forming environments of coal seam 2 and 9−2 based on the maceral composition and aromatic compounds in the Xingtai coalfield, China

Maceral composition and aromatic compounds were determined on column samples to study the peat-forming environments of Permian coal seam 2 and Carboniferous coal seam 9⁻² from the Xingtai coalfield, China. The macerals were dominated by inertinite in seam 2 and by vitrinite in seam 9⁻². Three maceral groups were selected as indicators of peat-forming environments. Two triangle diagrams were drawn based on the indicators to explicate the peat-forming environments of permian seam 2 and Carboniferous seam 9⁻². The results indicate that the peat of carboniferous seam 9⁻² formed dominantly in wet swamps, whereas the peat of Permian seam 2 formed dominantly in dry swamps and open moor environments. Supported by the National Natural Science Foundation of China(40773040) and the National Basic Research Program of China (2003CB214607)     

闭坑矿井地下水污染及其防治技术探讨

近年来,随着我国闭坑矿井数量的逐渐增加,闭坑后的矿区地下水环境问题日益突出。通过研究矿井闭坑产生的一系列水文地质效应,如含水介质条件、储水结构、地下水动力场、地下水化学场等的变化,阐明了矿井闭坑带来的地下水污染问题。根据地下水的埋深不同,初步将污染划分为浅层和深层污染两大类,由于污染模式的成因不同,又进一步对每类污染做了亚分类,并重点分析了各类污染的形成机制。最后结合国内外已有的地下水污染防治技术,针对闭坑矿井提出了防治地下水污染的措施。     

Development and Validation of a Spectrophotometric Method to Measure Sulfate Concentrations in Mine Water without Interference

Sulfate concentrations are determined in mine water by gravimetric, titrimetric, colorimetric, turbidometric, ion chromatographic, inductively coupled plasma absorption spectrophotometric, and other methods. Accurate sulfate measurement of mine water can be difficult due to interfering groups, cations, and anions, mainly arsenate (AsO₄ ³⁻) and phosphate (PO₄ ³⁻). In this paper, a simple and effective spectrophotometric method is described for the determination of sulfate in mine water. When the SO₄ ²⁻ reacts with barium chloranilate at pH 4.5 in aqueous ethyl alcohol solution, it releases acid-chloranilate, which shows maximum absorption at 350 nm and obeys Beer’s law over the concentration range of 10–1,000 mg/L. Results show that the proposed method was significantly more accurate than a conventional method. Absorbance was found to increase linearly with increasing concentration of sulfate, which is corroborated by the calculated correlation coefficient value of 0.999 (n = 7). The slope and intercept of the equation of the regression line were 0.00091 and 0.00778, respectively. The limit of detection and limit of quantification were found to be 0.03861 and 0.06774 mg/L, respectively. The validity of the described procedure was assessed. Statistical analysis of the result indicated high accuracy and good precision. The proposed method was successfully applied in mine water without interference from common groups like AsO₄ ³⁻ and PO₄ ³⁻. The relative standard deviations of the proposed method ranged from 0.03 to 0.26%, with recoveries of 99.79–101.57%.     

煤矸石中氮溶出的动态淋滤实验

为了探讨煤矸石中所含铵伊利石矿物和吸附的氮在风化过程中对周围环境产生的氮污染潜力,利用连续动态淋滤实验方法,对山西长治南寨煤矿和河南焦作朱村煤矿矸石进行淋滤实验,测定了滤出液中总氮、铵态氮、硝态氮和亚硝态氮的质量浓度变化,分析了煤矸石中各种氮的溶出行为。结果表明：煤矸石矿物表面吸附的硝态氮比较容易被水所溶出,并且随着淋滤时间的延长,滤液中硝态氮的含量迅速降低;煤矸石铵伊利石矿物晶格中固定氮的溶出是一个持续缓慢的过程,其大量溶出滞后于硝态氮的溶出;不管是酸性水或中性水,其滤液均呈偏碱性,这与煤矸石中NH+4的缓冲作用有关。实验结果揭示煤矿区矸石堆中的氮在风化过程中,会被雨水淋溶出来进入周围土壤或地表水体,造成周围环境氮的富集。     

辛置煤矿主要含水层的自由排水柱淋滤实验与水岩作用机理

辛置煤矿石炭系太原组K_2灰岩含水层与奥陶系峰峰组O_2f灰岩含水层水质参数相互重叠,利用传统的判别方法无法对这两个水源进行有效判别。为了解决辛置煤矿水源判别的问题,并揭示该矿4个主要含水层的水岩相互作用机理,对辛置煤矿4个主要含水层的岩芯样品进行自由排水柱淋滤实验。研究结果表明:①岩芯样品含有非矿物相的硫酸盐,4个主要含水层地层同样也含有硫酸盐和石膏矿物,造成淋滤液和灰岩含水层水样均富含硫酸根离子;②K_8,K_3,K_2和O_2岩芯淋滤液中SO_4~(2-)离子当量百分比均超过74%,Ca离子当量百分比均超过40%,所有淋滤液对应的水化学类型均为SO_4-Ca型;③所有淋滤液中阴离子含量大小顺序均为:SO_4~(2-)HCO_3~-Cl~-,K_8,K_3,K_2和O_2f岩芯淋滤液中阳离子含量顺序分别为:CaMgKNa,CaNaMgK,CaMgNaK和CaMgKNa;④K_2灰岩岩芯样品和淋滤液中Mo,Sb,U和Sr含量均高于奥陶系O_2f灰岩岩芯样品及其淋滤液,但Fe离子含量分布规律正好相反,该特征可以作为判别K_2和O_2f灰岩含水层的参考因素。辛置煤矿含水层的水化学特征受岩性、埋藏条件、地下水补径排及水动力条件的控制,含水层实际水质比淋滤液更为复杂多变。K_8砂岩含水层和K_3灰岩含水层的水化学类型分别为HCO_3-Na型和SO_4-Na型,与对应的淋滤液水化学类型差异较大;但K_2和O_2f灰岩含水层的实际水化学类型与淋滤液基本一致。二叠系K_8砂岩含水层中主要的水岩相互作用为溶解斜长石为主,部分区域中可能存在少量的硫酸盐溶解反应。太原组K_3灰岩含水层中的水岩相互作用主要为方解石和白云石矿物的溶解,以及部分硫酸盐和钠盐的溶解反应。太原组K_2灰岩含水层和奥陶系峰峰组O_2f灰岩含水层中主要的水岩相互作用均为方解石、白云石和硫酸盐的溶解,以及局部地段的脱硫酸作用。     

废弃煤矿采空区积水过程分析

煤矿废弃后，地下水动力场将发生变化，将形成不同于开采阶段的新的地下水动态平衡。通过对唐村煤矿水文地质条件和矿井废弃后地下水动力模式分析，分析了水位回弹过程中矿井的容水空间及其分布特点，分析了废弃矿井水位回弹的时空过程和最终动态平衡模式。     

The concentration of fluorine in coals and gangue of China

A detailed comparison was done between the data about the F in coals published at home and abroad, and associated with the special situation in China. An introduction also was made to illuminate the forming, occurrence and accumulation of the F in coals and its potential hazard to human and environment. Analytical data of coal samples were referred to study the great difference of the F content between coals and gangue. The results show that the average value of the F in the coal samples collected in different coalfields of China is 304×10⁻⁶, while that of gangue samples is surprisingly 1 319×10⁻⁶, especially the F content of coal ash from Bangmai in Yunnan Province reaches 4 800×10⁻⁶. It has been proved in many provinces of China that burning the coal and clay mixture can produce F contamination. Supported by “973 Program” (2006CB202202); The National Natural Science Foundation of China(40572090, 40272124)     

The removal of sulfate and metals from mine waters using bacterial sulfate reduction: Pilot plant results

A treatment process that bacterially converts sulfate into elemental sulfur via a hydrogen sulfide intermediate was demonstrated at pilot scale for the treatment of three mine waters that contained metals and sulfate. Ethanol served as the bacterial carbon and energy source. The mine waters were treated at rates that ranged from 50–150 L day⁻¹. Contaminant concentrations up to 13 mg L⁻¹ copper, 0.1 mg L⁻¹ mercury, 0.04 mg L⁻¹ cadmium, 3.5 mg L⁻¹ zinc, 0.68 mg L⁻¹ cobalt, 1.3 mg L⁻¹ nickel, 49 mg L⁻¹ iron, and 63 mg L⁻¹ aluminum were removed to meet water quality effluent limits. Manganese removal was about 80% under normal operating conditions but increased to 96% when the process was optimized for manganese removal. The process was shown to be capable of decreasing sulfate concentrations from 1800 mg L⁻¹ to less than 250 mg L⁻¹, nitrate from 100 mg L⁻¹ to less than 1 mg L⁻¹, arsenic from 8 mg L⁻¹ to less than 0.03 mg L⁻¹, and calcium from 310 mg L⁻¹ to less than 100 mg L⁻¹. Acid mine waters were neutralized using bacterially-generated alkalinity; no external alkalinity source was needed.     

煤矿区场地地下水污染防控技术研究进展及发展方向

目前,我国煤矿区场地地下水污染防控还处于初级阶段,缺乏矿井全生命周期地下水污染防控体系,造成了地下水污染防控不当、污染加剧等问题,在科学界定煤矿区污染场地和地下水污染流场单元的基础上,阐述了目前煤矿区场地地下水污染监测预警与防控技术的研究进展及发展方向。基于污染场地的定义,对煤矿区地下水污染场地和地下水污染流场单元进行了科学界定,明确了煤矿区地下水污染场地范围和地下水流场评估范围;分析了煤矿区场地矿井水污染类型和污染模式,阐明了煤矿开采和闭坑阶段地下水污染的主要特征因子;基于地下水污染风险理论,剖析了煤矿区场地地下水污染监测现状及预警技术思路;从矿井生产和闭坑角度出发,阐述了基于岩层控制、阻断材料以及地下储水等现有的保水开采技术途径,概述了矿井闭坑过程和闭坑后地下水污染防控的主动、被动技术手段。在上述分析的基础上,立足于矿井全生命周期不同阶段的特征,提出了煤矿区场地地下水污染防控技术的发展方向,主要包括：地下水污染精准探测技术,地下水特征污染物智能识别、监测预警技术与装备的研发,煤矿区地下水污染源头控制、过程阻断、末端修复等关键技术与工艺,力促形成煤矿区全生命周期地下水污染防控技术体系与规范,研究结果对于矿区地下水污染防控有一定的参考价值。     

Iron Removal by a Passive System Treating Alkaline Coal Mine Drainage

The Marchand passive treatment system was constructed in 2006 for a 6,000 L/min discharge from an abandoned underground bituminous coal mine located in western Pennsylvania, USA. The system consists of six serially connected ponds followed by a large constructed wetland. Treatment performance was monitored between December 2006 and 2007. The system inflow was alkaline with pH 6.2, 337 mg/L CaCO₃ alkalinity, 74 mg/L Fe, 1 mg/L Mn, and <1 mg/L Al. The final discharge averaged pH 7.5, 214 mg/L CaCO₃ alkalinity, and 0.8 mg/L Fe. The settling ponds removed 84% of the Fe at an average rate of 26 g Fe m⁻² day⁻¹. The constructed wetland removed residual Fe at a rate of 4 g Fe m⁻² day⁻¹. Analyses of dissolved and particulate Fe fractions indicated that Fe removal was limited in the ponds by the rate of iron oxidation and in the wetland by the rate of particulate iron settling. The treatment effectiveness of the system did not substantially degrade during cold weather or at high flows. The system cost $1.3 million (2006) or $207 (US) per L/min of average flow. Annual maintenance and sampling costs are projected at $10,000 per year. The 25-year present value cost estimate (4% discount rate) is $1.45 million or $0.018 per 1,000 L of treated flow.     

Numerical Simulation of Mine Water Inflow with an Embedded Discrete Fracture Model: Application to the 16112 Working Face in the Binhu Coal Mine,China

Properly accounting for the effect of heterogeneity of aquifers and accurately predicting mine water inflow during the mining process is still a challenging problem in China. We developed a stochastic modelling methodology that considers a large range of possible multi-scale fracture configurations and heterogeneous porous rock to predict mine water inflow close to the observed data. The coupled discrete fracture–rock matrix models were built for the Binhu coal mine 16,112 working face with the Monte Carlo method. The models were solved using the embedded discrete fracture model to calculate groundwater inflow from the aquifer beneath the coal seam floor. The calculated results and the observed groundwater inflows in the field agreed well. Sensitivity analysis indicates that groundwater inflow increases with increased fracture length and fracture density. The effect of natural fractures introduces a large uncertainty for the models, due to the existence of long fractures that could act as conduits between the Ordovician limestone and no. 14 aquifers. The results highlight the importance of multi-scale fractures on modeling and simulating flow in the mine area.