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Development Of Self-Locking Transfer Mechanism For Coal Samples From Pressure-Preserved Coring In Deep Mining, Zhu Pengfei, Li Jianan, Li Ju, Fu Chenghang, Ye Banghua

Coal Geology & Exploration

Pressure-preserved coring technology can directly store the collected deep coal samples at the bottom of the hole, so as to minimize the gas loss during the coring process. Besides, pressure transfer and testing of the pressure-preserved rock core is a technical prerequisite for the accurate determination of gas content. Then, how to achieve the precise docking from pressure-preserved coring to pressure transfer and testing has become a key technical difficulty that needs to be overcome urgently. Therefore, the research was carried out around the self-locking transfer mechanism, which is the core component of the docking transfer between the pressure-preserved coring …

Closure Trajectory Model Of Pressure-Preserved Controller For Coring In Coal Seam Surface Well, Guo Da, Zhang Yiwei, Wang Dingming, Fang Xin, Yang Bengao, Guo Lihua, Hou Lele, Zhao Xiang

Coal Geology & Exploration

The traditional method of coal exploration is to obtain coal samples using an open coring tool and estimate the gas loss through theoretical calculations. However, the measured gas content of these coal samples is generally low, significantly impeding the development and utilization of coalbed methane and compromising the safety of coal mining operations. To meet the demands of deep coal exploration, an innovative pressure-preserved coring tool was specifically designed for the coal seam surface wells. This tool has a total length of 6.7 m and can extract a 3 m long pressure-preserved coal core sample at a single time. In …

Fractal Theory-Based Permeability Model Of Fracture Networks In Coals, Xia Binwei, Liao Chuanbin, Luo Yafei, Ji Kainan

Coal Geology & Exploration

Fractures in coal reservoirs, which act as the major seepage pathways for coalbed methane (CBM), determine the permeability and CBM productivity of coal reservoirs. Research on the relationships between fracture structures and reservoir permeability is of great theoretical and practical significance for the accurate prediction of CBM productivity. Based on the classical cubic law-based permeability model, as well as the fractal theory, fracture network structures, and effective stress, this study built a permeability model containing complex bending fractures, which was then combined with the S & D (Shi-Durucan) model to build the permeability model of fractured coals under the action …

A Method For Classification Of Surrounding Rock Based On The Excavatability Performance And Adaptability Of Tunnel Boring Machines And Its Applications, Liu Jiawei, Zhang Sheng, Chen Zhao, Yang Zhanbiao, Ji Panjun, Wei Yonghui

Coal Geology & Exploration

The varying geological conditions of the surrounding rocks of coal mine roadways influence the wide application of full-face rock tunnel boring machines (TBMs). Therefore, accurately assessing the excavatability of rock masses in coal mines and the rock adaptability of TBMs is crucial for the efficient operation of TBMs. Based on the evaluation results of the parameters and excavatability of rock masses, this study built a classification model for rock mass excavatability using the technique for order preference by similarity to ideal solution (TOPSIS). Furthermore, combining the correlation analysis between the [BQ] values of different geological conditions and the utilization ratio …

Drillability And Mechanical Parameters Of Laser Hot Cracking Sandstones, Yang Lei, Yang Bengao, Liu Junjun, Zhou Xuemin, Xie Jing, Wang Chen, Guo Chenchen, Gao Mingzhong

Coal Geology & Exploration

Over recent years, shallow coal resources that can be easily mined have been gradually exhausted. As a result, conventional drilling techniques tend to face challenges such as low rock-breaking efficiency, high drilling costs, and environmental pollution in the exploration and exploitation of deep coal resources. Therefore, there is an urgent need to introduce a new auxiliary rock-breaking technique for drilling. Focusing on the new laser-assisted rock-breaking technology, this study systematically conducted mechanical and drillability tests on sandstones after laser irradiation for different durations, aiming to explore the temporal and spatial evolution of the temperature field of hard sandstones, the propagation …

Physical And Mechanical Properties Of Thermal Insulation Materials For In-Situ Temperature-Preserved Coring Of Deep Rocks, Xue Shouning, He Zhiqiang, Li Cong, Yu Bo, Lu Xuelian, Liu Wenyue, Yang Jianping, Wei Zijie

Coal Geology & Exploration

High temperature affects deep coal mining and other engineering activities. However, conventional coring methods for terrestrial hard rocks lack temperature-preserved measures, ignoring the effects of temperature on the physical and mechanical properties of rocks. Consequently, the parameters obtained are subjected to distortion, affecting the safe and efficient mining of resources such as deep coals. To make breakthroughs in the development of in-situ temperature-preserved coring technologies for deep rocks, this study proposed using the hollow glass microsphere/epoxy resin (HGM/EP) as thermal insulation materials and the physical and mechanical properties. The results are as follows: (1) With an increase in the HGM …

Sealing Performance Analysis And Structure Optimization Of Pressure-Preserved Controller For Pressure-Preserved Coring In Deep Coal Mine, Wang Tianyu, Li Jianan, Zhang Yiwei, Li Ju, Xie Heping

Coal Geology & Exploration

As the pressure-preserved controller is a core component of the deep coal in-situ pressure-preserved coring device, its sealing design plays a decisive role in the effect of pressure-preserved coring. In order to obtain the optimal sealing structure, a two-dimensional axisymmetric nonlinear contact model was established for the sealing structure of the pressure-preserved controller. On this basis, the effects of different groove design, cone angle selection and friction coefficient on the sealing performance were analyzed by orthogonal test method. Meanwhile, the stress changes of the sealing ring under different closing stages and medium pressures were studied. The results show that: the …

Research Advances On The In-Situ Pressure-Preserved Coring And Gas Parameter Determination For Deep Coal Seams, Xie Heping, Cui Pengfei, Shang Delei, Fan Dong, Chen Ling, Yang Mingqing, Du Lin, Gao Mingzhong

Coal Geology & Exploration

The in-situ gas pressure and content of coal seams are critical for the safe production of deep coal mines and the accurate evaluation of coalbed methane resources. To address the technical challenges of accurately determining in-situ gas content in deep coal seams, this study proposed brand-new principles of in-situ pressure coring and the tests of in-situ gas content and pressure. It also derived a calculation method for in-situ gas content in coal seams and a method for determining the in-situ gas pressure while considering the effects of moisture content and multiple gas components. Given the in-situ stress environment deep in …

A Preliminary Study Of Pressure-Preserved Coring Calculation Principle And Method For In-Situ Pressure In Deep Coal Seams, Cui Pengfei, Gao Mingzhong, Shang Delei, Li Jianhua, Chu Peng, Song Jie, Li Yongcheng, Hao Haichun

Coal Geology & Exploration

The accurate acquisition of in-situ gas pressure in coal seams is a key link in the chain of the prevention and control of gas disasters. Presently, it is still necessary to explore accurate, low-cost, and time-saving methods for determining gas pressure. Based on the in-situ pressure-preserved coring for deep coal seams, this study proposed a calculation method for in-situ gas pressure in deep coal seams and developed the calculation process. Using the constructed numerical model of the gas pressure evolution in the pressure-preserved space, this study verified the reliability of the proposed method by comparison with the theoretical and numerical …

Influence Of Gas Components On The Determination Of Gas Pressure In Coal Seams Under In-Situ Pressure-Preserved Coring, Chu Peng, Shang Delei, Li Jianhua, Ma Shaoming, Zhu Guodong, Cui Pengfei

Coal Geology & Exploration

Determining the pressure and content of coal seam gas based on pressure-preserved coring is an effective method for quickly and accurately calculating gas parameters. Coal seam gas is a multi-component gas mixture dominated by methane. Given that coals show different adsorption capacities for different gases and that the components in the mixed gas exhibit different partial pressures, the proportions of gas components can influence the calculation results of the content and pressure of coal seam gas. To accurately determine the in-situ gas pressure in coal seams based on the pressure-preserved coring, this study investigated the influence of gas components on …

Pressure Relief Mechanisms And Effects Of Liberation Seam Mining In 1000-M-Deep Coal Mines: A Case Study Of The Huafeng Coal Mine In Tai’An, China, Gao Yanan, Zhang Yao, Zhang Defei, Zhang Yudong, Zhao Weidong, Yu Liyuan

Coal Geology & Exploration

Liberation seam mining serves as an important approach to the prevention of deep dynamic disasters such as coal and gas outbursts, as well as rock bursts. Based on the Nos. 2613 and 2412 mining faces of a 1000-m-depth coal mine in the Huafeng Coal Mine in Tai’an, Shandong, this study investigated the engineering scientific issues such as the pressure relief mechanisms and effect evaluation of liberation seam mining through physical and numerical simulations. As a result, it determined the movement law of overburden strata and the characteristics of underground pressure after the mining of the liberation seam and ascertained the …

Exploring The Wetting Mechanism Of Surfactants For Coals Based On Molecular Simulations, Tong Yanjun, Yang Zundong, Song Jie, Li Yongcheng, Liu Yiting

Coal Geology & Exploration

With a gradual increase in the depth and mechanization degree of coal mining, secondary explosions of gas and coal dust have become increasingly severe. Chemical dust suppressants such as surfactants can reduce these explosions by effectively inhibiting the generation and diffusion of coal dust. To explore the inhibition mechanism of nonionic surfactants for hydrophobic coal dust, this study analyzed the basic physicochemical properties of typical hydrophobic coal dust at a depth of 1050 m using FT-IR, XRF, and XRD. This study built a molecular structure model of coal dust by combining test techniques such as EA, XPS, and ¹³C …

Remote Sensing And Gis Based Approach To Evaluate The Impact Of Stone Quarrying And Crushing Activities On Land Resources, R. S. Chaurasia, S. N. Mohapatra

Journal of Sustainable Mining

The land is one of the most treasures to support life, like food, fibre, medicine, and minerals, etc. Stone quarrying is one of the key elements which supports socio-economic development and industrial expansion. RS and GIS play an important role in environmental assessment to monitor the stone quarries and related activities for time to time. The present study was carried out to evaluate the impact of stone quarrying and crushing activities (SQCA) on land resources. Therefore, matrix change analysis of 2021, 2015, 2008 and 2003 were used for change detection. High-resolution Google Earth Pro images were used for the assessment …

Predictive Model Of Seismic Vibrations’ Peak Value Induced By Multi-Face Blasting, Krzysztof Fuławka, Lech Stolecki, Piotr Mertuszka, Marcin Szumny, Arkadiusz Anderko

Journal of Sustainable Mining

The seismicity level induced by blasting in the Polish copper mines is very important inlight of the efficiency of active rockburst prevention and safe conduct of blasting operations in the vicinity of the mining infrastructure such as shafts, workings, or function chambers (e.g., workshops, storages, etc.). Knowledge of the seismic vibrations’ peak value might be the basis for designing blasting works in a way that ensures desired seismic effect. However, current experiences show that Peak Particle Velocity prediction models developed so far do not apply to multi-face blasting, where there are many vibrations’ sources at the same time dotted across …

Managing The Rock Mass Destruction Under The Explosion, Maksym Kononenko, Oleh Khomenko, Ivan Sadovenko, Valeriy Sobolev, Yuliya Pazynich, Adam Smoliński

Journal of Sustainable Mining

Using the theory of elasticity and the main provisions of the quasi-static-wave hypothesis of the mechanism of the destruction of a solid medium under the action of an explosion, analytical modelling of the parameters of the formation of crumpling zones and crushing of the rock mass around the charging cavity during its explosive loading was carried out. Analytical models of the radii of the crumpling, intensive fragmentation and fracturing zones formed around the charging cavity in the rock mass during its explosive loading, taking into account the pressure of the explosion products, the limit of tensile-compressive strength of the rocks, …

Trace Metal Analysis Of Pond Sediments To Measure Deposition From A Coal-Fired Power Plant In Ackerman Mississippi, Charles Bills

Theses and Dissertations

Trace element sediment pollution due to coal power plants have been reported in many countries. In this study, pond sediment samples collected from locations around a coal fired power plant in Ackerman, MS, were evaluated for their trace element concentration and pollution status. The samples were collected at two depths to study changes in element accumulation over time. The samples were digested and the elements, As, Cd, Cr, Cu, Pb, Hg, and Zn were analyzed using ICP-MS. Results were then compared to known background concentrations as well as sediment quality guidelines and pollution thresholds. The sample locations downwind of the …

Application Geological Strength Index (Gsi) Quantification Method On The Characterization Of Carbonate Rock Mass, Singgih Saptono, Danu Mirza Rezky

Journal of Sustainable Mining

Determining GSI as a representation of the presence of rock mass in slope analysis continues to develop. The development of the quantitative GSI method was carried out because the basic (qualitative) GSI values were deemed too subjective so the results from the use of the quantitative GSIwere expected to be more objective and accurate. The method used is to combine 3 GSI quantitative methods to find GSI based on surface conditions and joint structure. The results showed that the Quantitative GSI value was smaller than the GSI predictive value (qualitative). The GSI approach with RQD and UCS parameters is also …

Investigating The Impact On Private Water Supply Of Hydraulic Fracturing Communication With An Abandoned Conventional Gas Well In New Freeport, Pa, Kiley Miller

Electronic Theses and Dissertations

In June of 2022 a “frac out” occurred in New Freeport, PA when an unconventional gas well under development by hydraulic fracturing, communicated with an abandoned gas well to the surface. An initial “zone of impact” encompassed much of the town’s main thoroughfare. Water samples were obtained from 17 private water wells, 5 springs and 1 pond (31 total samples) and analyzed for cations, anions, and light hydrocarbons. Methane was found in 18 of the samples, both located within and outside of the “zone of impact”. Mass ratio analyses indicated contamination from both unconventional and conventional wells. Interferometric Synthetic Aperture …

Design And Development Of Transition Metal-Based Electrocatalysts For Environmentally Friendly And Efficient Hydrogen Evolution Reactions (Her), Navid Attarzadeh

Open Access Theses & Dissertations

Hydrogen fuel is a clean energy source primarily because it emits no carbon dioxide (CO2). Sustainable energy alternatives have attracted the scientific community and policymakers as concerns over global warming and depletion of fossil fuels have increased significantly. Substituting H2 gas as a primary source for our daily energy consumption under the guideline of the hydrogen economy concept has not progressed as anticipated because of inadequate efficiency associated with the generation (electrolyzer) and utilization (fuel cell) devices. However, there are challenges associated with hydrogen that must be overcome for it to become a truly sustainable and widespread energy source. The …

Global Energy Consumption: An Analysis Of Variables That Shape Per Capita Usage, Or How Pump Price, Urbanization, And Fossil Fuels Imports Impact Fossil Fuels Consumption Per Capita Across Oecd Countries, Mila Demchyk Savage

Graduate Program in International Studies Theses & Dissertations

Among reasons explaining the importance of studying fossil fuel consumption are: crude oil is a subject of the international commodities market, thus, any fluctuation related to its' availability or price would impact the rest of the World; natural resources like oil, gas, and coal are limited; the extensive use of fossil fuels harms our surroundings, creating many environmental concerns; every human (on average) has been using more energy since 1971 and the trend is expected to continue. The upward trend is not consistent among individual countries. Therefore, the core question of my research is, `Why do some countries consume less …

Development And Characterization Of Lead & Lead-Free Perovskite Solar Cell Materials, Rubaiya Murshed

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years, perovskite photovoltaic technology has offered enormous viability and dimensionality in solar cell research. As a light-harvesting active layer, Perovskite generated remarkable development in device efficiency of 25.7% for the single-junction solar cell, and over 33% for the perovskite/silicon tandem solar cell. Also, perovskite-perovskite tandem solar cell (also called all-perovskite tandem solar cell) shows great potential in device performance and achieved a power conversion efficiency (PCE) of 26.4%. Transitioning photovoltaic technology from the laboratory to commercial products, high PCE, low cost, long lifetime, and low toxicity are some of the critical factors to consider during material selection. Pb-halide …

Nickel Recovery From Low-Grade Laterites: Study Of Thermal Pre-Treatments To Improve The Efficiency Of The Hydrometallurgical Process, Johana Borda, Robinson Torres

Journal of Sustainable Mining

The processing of lower-grade laterites to obtain nickel has increased due to the gradual depletion of higher-grade sulphide ore reserves. However, the extraction from laterites has been limited because conventional technologies imply a considerable expense of energy or reagents. In this document, the effect of thermal pre-treatments on a laterite sample is demonstrated to improve nickel leaching under moderate conditions. The influence of agents such as coke, coal and NaCl in the heat treatment was also studied. With the results it is presumed that part of the nickel occluded in the goethite migrates to the iron oxides surface during the …

European Feedback On Post-Mining Seismicity, Isabelle Contrucci, Dalija Namjesnik, Peter Niemz, Paloma Primo, Andrzej Kotyrba, Grzegorz Mutke, Petr Konicek, Pascal Dominique, Tobias Rudolph, Stefan Möllerherm, Jannes Kinscher, Emmanuelle Klein, Simone Cesca

Journal of Sustainable Mining

Following the Paris Agreement adopted in 2015, Europe has committed to reducing its greenhouse gas emissions. In this context, the abandonment of coal as an energy source, both in terms of consumption and production, will lead to the closure of many mines in the years to come.

Mine closure guidelines to manage residual mining risks already exist in European countries. However, they do not include post-mining seismic risk management due to a lack of sufficient studies and knowledge on this subject. After mining closure, the flooding of the mining works leads to hydromechanical loading of the underground and, in the …

Study On Container Linerroute Optimization Of Southeast Asia Route Of M Shipping Company, Lefan Liu

World Maritime University Dissertations

No abstract provided.

Investigating The Determinants Of Ordering Alternative Fueled New Vessels, Yuantao Chen

World Maritime University Dissertations

No abstract provided.

Propagation Of Hydraulic Fractures In Thin Interbedded Tight Sandstones, Yang Fan, Mei Wenbo, Li Liang, Sun Zening, An Qi, Yang Qi, Lu Meiquan, Yang Ruiyue

Coal Geology & Exploration

Thin interbedded tight sandstone reservoirs are characterized by strong vertical heterogeneity due to the superimposed pattern of the deposited sandstones and mudstones. As a result, hydraulic fractures are difficult to propagate vertically to effectively connect the reservoirs. Given this, ascertaining the vertical propagation patterns of hydraulic fractures in thin interbeds is of great significance for the development of thin interbedded tight sandstones. With the thin interbedded tight sandstone reservoirs of the lower Shihezi Formation in the Linxing block, Ordos Basin as a case study, this study built the fracture propagation model of these sandstones. Accordingly, it analyzed the effects of …

Iron Occurrence In Coal Measures And Its Release Mechanism During Water-Rock Interactions: Taking A Mine In The Eastern Grassland As An Example, Wang Tiantian

Coal Geology & Exploration

The mine water with iron out of limit corrodes the water distribution pipeline and the industrial equipment, thereby damaging the liver of human body, and further threatening the human health. The enrichment or dilution of iron in mine water is determined by the iron content and its occurrence in coal measures, as well as its release mechanism during water-coal and water-rock interactions. Herein, 18 groups of coal and rock samples were collected from a mine in the eastern grassland, and had the iron content, occurrence and carrier in the coal measure analyzed with an inductively coupled plasma mass spectrometry (ICP-MS), …

Change Detection Of Open-Pit Mines Based On Fm-Unet++ And Gf-2 Satellite Images, Du Shouhang, Li Wei, Xing Jianghe, Zhang Chengye, She Changchao, Wang Shaoyu, Li Jun

Coal Geology & Exploration

Automatic extraction of land use change information in open-pit mines using the remote sensing and deep learning technology is of great significance for the mining monitoring and ecological environmental protection. A novel deep learning model FM-UNet++ was constructed for the change of land use types in complex and heterogeneous mining scenarios, and the automatic change detection of open-pit mines was achieved using the Gaofen-2 (GF-2) satellite images. Firstly, the change detection dataset of open-pit mine was produced through data surveys and visual interpretation, which was augmented by data enhancement. Secondly, the FM-UNet++ for open-pit mine change detection was constructed by …

Underground Coal Gasification Field Tests In China: History And Prospects, Qin Yong, Yi Tongsheng, Yang Lei, Zhou Yongfeng, Wang Jun, Wang Lingxia

Coal Geology & Exploration

To achieve peak carbon dioxide emissions and carbon neutrality in China, a low-carbon and efficient coal energy structure is essential for the sustainable energy development of China. Underground coal gasification (UCG) is an important strategy for transforming the coal energy structure in China. Based on the review of previous literature, this study analyzes the exploration history of the UCG field tests in China and delivers the prospects of UCG industrialization in China. The analytical results show that the development and field tests of UCG technologies in China have experienced five stages, namely the initial attempt, silence/recovery, extensive explorations, making technological …

Construction And Engineering Applications Of Block Model For Coal Seam Value Considering The Variations In Coal Seam Thickness And Quality, Liu Feiyue, Yang Ke, Yang Tianhong, Kan Lei, Fu Kai

Coal Geology & Exploration

The variations in coal seam thickness and coal quality parameters (i.e., calorific value, volatile matter, ash content, and sulfur content) determine the spatial distribution of coal prices. The accurate characterization of coal seams’ economic value plays an important role in the rational mining and utilization of coal resources. This study first determined that the geological attributes of coal seams including their thickness and coal quality are regional variables. Based on this, this study discretized geological bodies in the study area using a block model. Then, using a geostatistical method, this study obtained the experimental semivariograms of coal seam thickness and …