Mining Engineering Commons^™

Hydrogeochemical Evolution Of No.15 Coal Seam And Limestone K2 In Southern Qinshui Basin, Li Zhongcheng, Wu Jianguang, Wang Jianzhong, Wu Xiang, Lu Guojun

Coal Geology & Exploration

Based on the water test data of No.15 coal roof K₂ limestone and No.15 coalbed methane well in the southern Qinshui basin, the characteristics, types and the genetic mechanism of water chemical composition were systematically studied by statistical and comparative methods. The evolution model was built to systematically describe the various reactions and effects of limestone and coalbed water in the recharge zone, runoff zone and detention zone. The results show that the K₂ limestone water and the No.15 coal seam water will undergo ion exchange, mixing and CO₂ action. The K₂ limestone water is mainly …

Effect Of Acidification On The Microstructure And Physical Properties Of Shale, Chen Liuyu, Li Xijian, Shen Zhonghui, Xu Shiqing, Ma Shengxiang, Yin Xin

Coal Geology & Exploration

As the main shale gas reservoir in Guizhou, it is proved that Longmaxi Formation has good shale gas accumulation conditions and resource development potential. In order to reveal the response law of acidification on the micropore structure and physical properties of Longmaxi Formation shale in Guizhou, the difference in physical properties of shale microstructures before and after acidification, such as pore volume, porosity, specific surface area and pore size distribution was quantitatively characterized by X-ray diffraction(XRD) analysis, mercury intrusion measurement, low-temperature nitrogen adsorption and nuclear magnetic resonance(NMR) experiment. The structural characteristics of the shale pores before and after acidification were …

Water Environment Comprehensive Forewarning For Waterlogged Area In Huainan Based On Weber-Fechner Law, Pei Wenming, Zhang Hui, Ju Changhua, Yao Suping, Ren Yongle, Ma Mengxiao, Qiu Kuanbiao

Coal Geology & Exploration

In area with high groundwater level in the east of China, long-time underground coal mining results in a large subsidence water area on the surface. The risk of water environment pollution in subsidence waters is increasing gradually with the influence of human activities. According to Weber-Fisher law, this paper took Panji waterlogged area of Huainan as the research object, selected the water quality evaluation indexes closely related to the water environment of the waterlogged area, analyzed the water environmental conditions of the waterlogged area in different periods, and quantitatively reflected the time and the area of the water environment quality …

Performance Test And Proportioning Optimization Of Loess-Based Grouting Materials In Coal Mining Subsidence Area Of Northern Shaanxi, Cao Xiaoyi, Wang Yutao, Liu Xiaoping, Cao Zubao, Wu Boqiang

Coal Geology & Exploration

Grouting is the main treatment method of mining subsidence area, and the grouting materials have great influence on the grouting effect and cost. Taking the grout mix composed of loess and cement used in northern Shaanxi as the research object, the viscosity, the gelation time, the stone rate and 28 d uniaxial unconfined compressive strength of loess grout were studied by single factor and orthogonal tests. The influencing factors and changing rule of each index were analyzed. Meanwhile, the GA-BPNN prediction model of loess-based grout was established, and the multi-objective global optimization was carried out through GA. The grout ratio …

Exploration And Quantitative Evaluation Of Overburden Strata “Three Zones” In Deep Strip Mining, Liu Zhen, Wang Yutao, Liu Xiaoping, Wang Xiaodong

Coal Geology & Exploration

In order to study the height of overburden fractures in deep strip mining, engineering geological drilling, borehole television and coalfield well logging have been applied to detect and analyze the overburden fractures in a coal mine in Jining coalfield. The results indicate that, under the strip mining with gentle dip(6°), deep depth(538 m) and 1:2 mining-retention ratio(mining -50 m and remaining -100 m), the “three zones” develop prominently, presenting “wavy” destruction in space, and the goaf has no obvious cavity. The height of caving zone is 8.45 m which is 3.0 times of the mining height, and the fault zone …

Stacking Angle Of Slurry-Aeolian Sand Dual-Phase Medium Filling Material, Bai Zhongrong

Coal Geology & Exploration

Stacking angle is an important parameter to describe the spatial accumulation pattern of filling material in the goaf. It has important guiding significance for determining the drilling distance, optimizing the slurry configuration and adjusting the grouting process parameters. In order to grasp the variation law of stacking angle of slurry-aeolian sand dual-phase medium filling material, using self-flow stacking model experiment of tailings and rheological properties experiment, the mixing ratio of aeolian sand was taken as a variable to determine the slurry accumulation parameters and rheological parameters on different conditions of sand ratio. Based on this, Sofra & Boger formula was …

The Structural Characteristics And Their Influence On Production Of Buliangou Coal Mine, Ma Liang, Guo Rui

Coal Geology & Exploration

Jungar coalfield is located at the turning point of Yimeng uplift and Jinxi flexure belt in Ordos basin. There are many kinds of mine structures in the coalfield, and the structural complexity has changed greatly before and after the exposure by mine production. Taking the fold, fault, karst collapse column, igneous rock intrusion and other geological structures exposed by geological exploration and mining as the research object, quantitative or semi-quantitative evaluation of structural development characteristics in the mine was carried out by means of mathematical statistics, and the formation mechanism, evolution background of different geological structures were analyzed. The main …

Physical Simutation Experiment Investigation On Hydraulic Fracture Propagation In High-Dip Coal Seam, Jiang Wei, Zhang Jun, Zhong Jie, Zhao Chen, Tang Zhuyun, Lu Haibing, Yi Xinbin, Wang Hai

Coal Geology & Exploration

In order to study the hydraulic fracture geometry in high-dip coal seam, a large-scale true triaxial fracturing simulation system was used to carry out physical simulation experiments, and the hydraulic fracture geometry of the maximum horizontal principal stress along the strike direction and along the dip direction-in 60° dip coal seam were investigated respectively. Experimental results of the maximum principal stress direction along the strike direction show that: hydraulic fracture initiation is easily; fracture height is limited in the whole time; fracture connectivity is good; fracture propagates mainly along bedding and natural fracture, vertical fracture is formed; the influence of …

Practice And Understanding Of Multi-Layer Drainage Of Cbm Wells In Liupanshui Area, Liu Jiang, Sang Shuxun, Zhou Xiaozhi, Bi Caiqin, Jin Jun, Shan Yansheng

Coal Geology & Exploration

To improve the effect of drainage and extraction of coalbed methane wells, it is necessary to divide the drainage and production stages reasonably and formulate corresponding control measures. Based on the previous exploration and trial production of coalbed methane in Liupanshui area, this paper analyzed the geological characteristics of coalbed methane and the development characteristics of coal reservoirs in the area, and studied the drainage effect of the combined layers of two wells comparatively. The research shows that the area has several basic characteristics, including many coal seams, thin single-layer thickness, high gas content, high reservoir pressure, low coal seam …

Application Of Time Series Model In Water Inflow Prediction Of Working Face, Shi Longqin, Wang Yaru, Qiu Mei, Gao Weifu

Coal Geology & Exploration

In practical production of mines, the prediction of mine water inflow is of great significance for mine water prevention and control. Taking working face 1301 of Yuncheng coal mine as the research object, and without considering the influence of seasonal factors, ARIMA-the time series analysis model-is used to establish the functional relationship between mine water inflow and time, which proves that the time series of water inflow in working face 1301 of Yuncheng coal mine is affected by seasonal factors. Then, based on the principle of addition and decomposition of time series, the long-term trend, seasonal indexes, circulating factors and …

Experiment Of Mesostructure And Hydrologic Characteristics Of Weakly Cemented Soft Rocks In Western China, Zhang Jiafan, Cheng Shufan, Wang Huan, Gao Zhuang, Zhou Feiwen, Zhou Hongwen

Coal Geology & Exploration

In order to accurately grasp the hydrologic characteristics of weakly cemented soft rocks in western China, the hydraulic and mechanical properties of red sandstone collected from northern Shaanxi mining area were tested. Based on the scanning image of scanning electron microscope(SEM), the mesostructural characteristics of the rocks were analyzed, and the relationship between the mesostructure of rocks and its macroscopic hydrologic characteristics was established. The results show that red sandstone has obvious characteristics of water saturation and water absorption and expansion, and its softening coefficient is 0.64. Under the action of pressure water erosion and dry and wet cycle, the …

Acoustic Emission Characteristics And Damage Evolution Of Coal-Rock Under Different Confining Pressures, Yu Jie, Liu Xiaohui, Hao Qijun

Coal Geology & Exploration

Using PCI-2 acoustic emission(AE) system, the AE experiments of different confining pressures (0, 8, 16, 5 MPa) were carried out in Baijiao coal mine in Furong, Sichuan Province, in order to reveal the change rule of ringing count rate, the temporal and spatial distribution of AE, b value of AE and damage characteristics of damaged coal-rock under different confining pressures, and to provide a theoretical basis for prediction of coal-rock damage. The results show that the AE phenomenon can reflect the crack propagation of coal-rock and the confining pressure can restrain the damage of coal-rock. With the increase of confining …

Test Of Mechanical Properties Of Limestone Under Hydraulic Pressure-Stress Coupling, Tian Shukun

Coal Geology & Exploration

To study the mechanical properties of limestone with water-rich saturated circumstance under water pressure-stress coupling, compression failure tests of limestone samples with different water pressure were carried out by using a self-developed permeability test device, the device can realize uniaxial compression test. Then, the stress-strain characteristics of limestone, the effect of hydraulic pressure on uniaxial compressive strength, the elastic modulus and the deformation modulus, and the correlation between breaking characteristics and hydraulic pressure were tested. The results show that the increased hydraulic pressure has a significant influence on the stress-strain curve and strength characteristics. With the increase of hydraulic strength, …

Influence Factors And Formation Properties Of Temperature Field In The Frozen Wall Of Double Ring Pipes, Li Huaixin, Lin Bin, Wang Peng

Coal Geology & Exploration

In order to research the change law of the temperature field of the frozen wall of double-circle pipes, an auxiliary shaft in Huainan coalmine was taken as the research object, the FLAC^3D software was used to numerically simulate the formation process of the temperature field of the frozen wall of double-circle pipes and the influence of different factors on average temperature of frozen wall based on the relevant geological parameters. The research results show that temperature of the soil in the double-circle pipes is the lowest, and temperature on both sides increases gradually, the interval between frozen holes is …

Detection Technique And Application Of Transmission In-Seam Wave In Thin Coal Seam, Yang Hui

Coal Geology & Exploration

Aiming at the problem of serious attenuation of channel wave in thin seam and its limited distance of propagation, a method of restricted CT imaging was proposed by using the furthest in-seam wave propagation distance. Firstly, the variation of in-seam wave frequency with different thickness of coal seam was studied by theoretical derivation. Taking a 1.5m thin seam as the main research object, the attenuation characteristics of channel wave were simulated by forward modeling, and the effective propagation distance of channel wave was determined. The actual data of No. 15 coal seam in a coal mine in Shandong Province shows …

Common Midpoint Gather Constraint-Based Impedance Inversion Of Ground Penetrating Radar, Dai Qianwei, Ning Xiaobin, Zhang Bin

Coal Geology & Exploration

GPR impedance inversion is an effective method to obtain accurately the intrinsic parameters of the subsurface medium. This method relies on low frequency information provided by logging data, but it is rarely accompanied by drilling in practical applications. To solve the problem, the common midpoint velocity analysis is employed to provide more low frequency component information for impedance inversion of GPR to finely reconstruct the dielectric parameter of subsurface in the framework of velocity-constrained inversion technique. Firstly, a layer model is specifically set up as an example to verify the feasibility of the developed velocity- constrained inversion to regulate the …

Flow Simulation Considering Adsorption Boundary Layer Based On Digital Rock And Finite Element Method, Yong Fei Yang, Ke Wang, Qian Fei Lv, Roohollah Askari, Qing Yan Mei, Jun Yao, Jie Xin Hou, Kai Zhang, Ai Fen Li, Chen Chen Wang

Michigan Tech Publications, Part 1

Due to the low permeability of tight reservoirs, throats play a significant role in controlling fluid flow. Although many studies have been conducted to investigate fluid flow in throats in the microscale domain, comparatively fewer works have been devoted to study the effect of adsorption boundary layer (ABL) in throats based on the digital rock method. By considering an ABL, we investigate its effects on fluid flow. We build digital rock model based on computed tomography technology. Then, microscopic pore structures are extracted with watershed segmentation and pore geometries are meshed through Delaunay triangulation approach. Finally, using the meshed digital …

Remote Sensing And Three-Dimensional Photogrammetric Analysis Of Glaciofluvial Sand And Gravel Deposits For Aggregate Resource Assessment In Mchenry County, Illinois, Usa, Xiaodong Miao, Christopher J. Stohr, Paul R. Hanson, Qiansuo Wang

School of Natural Resources: Faculty Publications

Sand and gravel deposits, one of the most common natural resources, are used as aggregates mostly by the construction industry, and their extraction contributes significantly to a region's economy. Thus, it is critical to locate sand and gravel deposits, and evaluate their quantity and quality safely and quickly. However, information on aggregate resources is generally only available from conventional two-dimensional (2-D) geologic maps, and direct field measurements for quality analysis at outcrops are time consuming and are often not possible due to safety concerns, or simply because exposures are too difficult to access. In this study, we presented a methodology …

Spectroscopic Measurements Of Dissolved O3, H2o2 And Oh Radicals In Double Cylindrical Dielectric Barrier Discharge Technology: Treatment Of Methylene Blue Dye Simulated Wastewater, Emile Salomon Massima Mouele, Jimoh O. Tijani, Milua Masikini, Ojo O. Fatoba, Chuks P. Eze, Chionydua T. Onwordi, Myo Tay Zar Myint, Htet Htet Kyaw, Jamal Al-Sabahi, Mohammed Al-Abri, Sergey Dobretsov, Katri Laatikainen, Leslie F. Petrik

Mining Engineering Faculty Research & Creative Works

Advanced oxidation technologies (AOTs) focusing on nonthermal plasma induced by dielectric barrier discharge are adequate sources of diverse reactive oxygen species (ROS) beneficial for water and wastewater treatment. In this study, indigo, peroxytitanyl sulphate and terephthalic acid methods were used to approximate the concentrations of O₃, H₂O₂ and OH produced in a double cylindrical dielectric barrier discharge (DCDBD) plasma configuration. The effect of pH and scavengers as well as the amount of chemical probes on the generation of oxidants was investigated. The efficiency of the DCDBD reactor was further evaluated using methylene blue (MB) as …

Prediction Of Flotation Efficiency Of Metal Sulfides Using An Original Hybrid Machine Learning Model, Rachel Cook, Keitumetse Cathrine Monyake, Muhammad Badar Hayat, Aditya Kumar, Lana Alagha

Materials Science and Engineering Faculty Research & Creative Works

Froth flotation process is extensively used for selective separation of base metal sulfides from uneconomic mineral resources. Reliable prediction of process outcomes (metal recovery and grade) is vital to ensure peak performance. This work employs an innovative hybrid machine learning (ML) model—constructed by combining the random forest model and the firefly algorithm—to predict froth flotation efficiency of galena and chalcopyrite in relation to various experimental process parameters. The hybrid model's prediction performance was rigorously evaluated and compared against four different standalone ML models. The outcomes of this study illustrate that the hybrid ML model has the prediction ability to process …

Leaching Kinetics Of Rare Earth Elements From Fire Clay Seam Coal, Xinbo Yang, Rick Q. Honaker

Mining Engineering Faculty Publications

Recovery of rare earth elements (REEs) from coal samples collected from the Fire Clay coal seam using diluted mineral acid solutions was investigated. The initial processing step was coal recovery using conventional froth flotation which concentrated the REEs in tailing material resulting in an upgrade to values around 700 ppm on a dry whole mass basis. Leaching experiments were performed on the flotation tailings material using a 1.2 M sulfuric acid solution adjusted to a temperature of 75 °C to study the extractability of REEs from coal material. The effect of particle size, leaching time, leaching temperature, and solid concentration …

Tri-State Mining District, Ecological System, And Human Health: Systematic Literature Review Analysis, Jihyun Jane Min

Posters

Objective: Although extensive research exists on corrosive environments in the Tri-State Mining District (TSMD), there has been a lack of research on how such harmful effects in the TSMD could affect residents living in those areas. However, quite recently, such research regarding relationships between the health conditions of low-income residents and toxic elements in TSDM began to grow. Therefore, the increase of empirical studies means greater complexity of the findings that require a more intricate understanding.

Methods: To meet the necessity of the study, this research was conducted by an extensive systematic review of the literature on the harmful effects …

Key Technology For Rapidly Drilling Large Diameter Destressing-Drillhole In Rockburst Coal Seam, Wei Hongchao, Wang Yi, Wang Bo

Coal Geology & Exploration

In order to improve the hole forming rate and construction efficiency of large diameter destressing-drillhole in rockburst mine, based on the analysis of the stress characteristics of coal rock in rockburst coal mine, the dynamic instability characteristics of destressing-drillhole and the construction features, the key points for drilling large diameter destressing-drillhole, the efficient discharge of cuttings and fast drilling/lifting were proposed. Combining with the discharge of cuttings method by dual-power, the technology and equipment for rapidly drilling large diameter destressing-drillhole in rockburst coal seam were formed finally after the design and optimization of key equipment, drilling tools, technology and drilling …

Foam Drilling Technology And Application For Broken Soft Coal Seam In Underground Coal Mine, Ji Qianhui, Dong Mengmeng, Liu Jianlin, Shi Lei

Coal Geology & Exploration

Aiming at the limitation of middle pressure air drilling for gas drainage in soft and broken coal seam, such as limited drill cutting removal capacity, and dust pollution, foam drilling technique research in underground coal mines was carried out. CFD simulation of the flow field during the drilling process was conducted to obtain the optimized drilling tool structure parameters for efficient drill cutting transportation. Optimal structural parameters of wide-blade milled auger drill rod with the number of heads 3, the groove width 26 mm, and the pitch 110 mm were determined. A foam perfusion system suitable for underground coal mining …

Distribution And Resource Prospect Of Metal Ore Spots(Deposits) In Coal Of Different Coal-Forming Ages In Northern China, Ning Shuzheng, Huang Shaoqing, Zhang Li, Huang Wenhui, Cao Daiyong, Yuan Jianjiang, Zhang Jianqiang, Zhu Shifei, Yan Deyu, Liu Kang

Coal Geology & Exploration

In some cases, metals such as germanium, gallium, lithium and rare earth elements can be enriched in coal, which is an important potential source of these metals. There are abundant coal resources in northern China, and a large number of coal-metal ore spots(deposits) have been found, and the distribution of these ore spots(deposits) shows certain temporal and spatial characteristics: Metals in Permo-Carboniferous coal occur mainly as gallium and lithium-enriched ore spots, mainly are distributed in the northern coalfields of North China coal bearing regions and mining areas such as Pingshuo and Jincheng in Shanxi Province; the metal enrichment in Early-Middle …

Causes Of Anomaly Of Rare Earth Elements Of Seam 2 Of Yan’An Formation In The Northern Margin Of Ordos Basin And Its Geological Significance, Yang Yi, Lyu Dawei, Zhang Jianqiang, Wu Dun

Coal Geology & Exploration

The cause of rare earth elements(REE) anomalies in No.2 coal seam of the Yan’an Formation in the northern margin of the Ordos basin has been controversial. This paper takes Dahaize coal mine, Yulin area with well developed No.2 coal as an example to analyze REE, mineralogical characteristics of coal and partings, and to reveal the causes of anomaly of REE by Inductive Coupled Plasma Mass Spectrometry(ICP-MS) and Scanning Electron Microscopy(SEM). The results show that the total rare earth element(∑REE) concentration in the coal samples ranges from 3.71 to 46.21 μg/g. Light rare earths elements(LREE, La-Eu) are more abundant than heavy …

Influencing Factors Of The Dynamic Permeability Of Cbm Reservoir And Cbm Well Drainage Control Measures, Wang Qing, Yang Fei, Gong Weicheng, Xu Tianxin, Li Yichao

Coal Geology & Exploration

The drainage and production control method has significant impact on the permeability of coalbed methane reservoir. Based on the main control factors of the permeability at different stages of drainage and production of coalbed methane wells, this paper puts forward targeted drainage and production countermeasures with the goal of improving the permeability. When the bottom-hole flow pressure was greater than the original reservoir pressure, the step-down velocity was between 0.08 and 0.1 MPa/d to reduce fracturing fluid and velocity-sensitive damage. When the bottom hole flow pressure was between reservoir pressure and desorption pressure, the pressure could be reduced at a …

Dynamic Evolution Law Of Water Accumulation Range In Coal Mining Subsidence Area With High-Level Groundwater, Chen Xiaoxie, Zhang Wentao, Zhu Xiaojun, Liu Hui, Zhang Min, Sun Aiguo, Yang Xiaoyu

Coal Geology & Exploration

In order to study the dynamic evolution law of the water accumulation range with high-level groundwater, the working face 1031 of Wugou coal mine was taken as the research area. Based on Landsat-8 remote sensing data, the evolution law of water accumulation range above working face 1031 during 2013-2017 was summarized and the influence of factors such as net rainfall, groundwater depth and working surface propulsion distance on the evolution of water accumulation range was analyzed. The concept of the boundary angle of the water accumulation range was proposed, and the functional relationship between the angle and the mining time …

Preparation Of Underwater Quick-Set And Expansion Polyurethane Grouting Material And Its Properties, Yang Zhu, Xue Ren, Wang Jun, Lan Zhili

Coal Geology & Exploration

Quick plugging and dynamic grouting technology under complex geologic conditions in mines is a technical problem in the field of grouting and one of the effective solutions is to develop new chemical grouting materials. Based on the reaction principle of polyurethane materials, we carried out the research and development on production formula of polyurethane grouting materials. By analyzing the polyurethane synthesis reaction temperature and the way of adding reagents as well as conducting contrast experiments on various auxiliaries and additives the best formula for the material was determined. It was found that the grouting material prepared by 4% nano silica …

Classification Of Hidden Faults In Coal Seam Floor And Measures For Water Inrush Prevention, Liu Zewei, Liu Qisheng, Liu Yang

Coal Geology & Exploration

The floor hidden faults with mine water bursting coefficient between 0.06 and 0.1 MPa/m have not been classified scientifically in combination with mining. Based on the characteristics of hidden faults in coal seam floor and the vertical relationship between the location of the top interface of the hidden fault and the " Three Underlying Belts", the hidden faults in coal seam floor are classified into three types: high, middle, and low from the perspective of mine water prevention of the floor. Through theoretical analysis and case analysis of water inrush, it is pointed out that the high hidden fault with …