Sustainability Commons^™

Analysis On The Development Characteristics And Influencing Factors Of Gas Pores In Coal, Zhang Hui, Wu Jing, Yuan Liying, Song Xiaozhong, Lin Bowei

Coal Geology & Exploration

Based on the study of coalfield geology and coal petrology, using field emission scanning electron microscopy(FESEM) as the main observation method, nanoscale pore research on coals was carried out for different regions, different geological ages and different metamorphic degrees. The results show that gas pores in coal are the pores left by coalbed methane(gas) generation, accumulation and escape during coal metamorphism, are secondary porosity. The pore diameter is mainly at nanometer size and round shape, with uneven density and distribution. The gas pore is intensive, often forms gas pore group, gas pore zone and gas pore nest. The gas pore …

Analysis On Water Burst Characteristics During United Mining Of Multiple Coal Seams In Binchang Mining Area, Wu Mouda

Coal Geology & Exploration

Aiming at the abnormal water inrush in working face of united mining of multiple coal seams in Binchang mining area, the relationship between gushing water and formation characteristics, geological structure and ground pressure were analyzed based on the characteristics of water inrush. The causes of abnormal water inrush were discussed from the aspects of water source, water-conducting channels and water inrush mechanism. The analysis shows that Luohe Formation has become the direct or indirect aquifer for coal mining under the influence of mining intensity and formation factors of Anding Formation; the formation with large dip generated by the fold structure …

Risk Judgment Technology Of Water Accumulation In Overlying Goaf Based On Plate Shell And Fracture Mechanics Theory, Ti Zhengyi, Zhang Feng, Qin Hongyan, Zhu Zhijie

Coal Geology & Exploration

In order to avoid the threat of water penetration from the goaf of overlying seam No.6 during mining seam No.10 in Shengli coal mine of Linfen, Shanxi, plate-shells theory and fracture mechanics theory were used to establish the mechanics model of the development height of water-conducting fissure zone and the rupture depth of the floor. The water conducting fissure zone developmental height in districts I-VI of coal seam 10 is 46.77 m, 48.86 m, 56.05 m, 56.14 m, 56.33 m and 55.20 m, and the rupture zone depth of the floor in districts I-IV areas of coal seam 6 is …

Test On The Strength Of The Backfill Fine Sand Mixture Composed Of Cement-Fly Ash-Cinder, Wen Liang, Yan Changhong, Zhang Zheng, Xu Baotian, Zhang Shunjing, Zhang Dongping, Zhou Yinkang

Coal Geology & Exploration

By using orthogonal test to analyze the influence of cement content, fly ash content and cinder content, the non-confining compression strength test was carried out for the stability of large-scale landfill base structure and for the saving costs. The strength at different curing ages was analyzed by variance, and the reinforcement mechanism was also studied. The test results showed that the optimal ratio of cement stabilized soil under different factors is 20% of cement, 15% of fly ash, 10% of cinder, and the strength is the largest at this point. And the influence of cement content on the strength of …

Acoustic Emission Test Of Calcareous Sands Under Undrained Condition, Yang Chao, Wang Kai, Qiao Liping, Meng Qingshan, Wang Ren

Coal Geology & Exploration

Calcareous sand acoustic emission was tested under undrained condition to study the law of acoustic emission with different confining pressure, shear rate, initial void ratio and grading. The results showed that when the confining pressure was lower than 400 kPa, calcareous sand acoustic emission event rate increased with confining pressure. But when the confining pressure was increased to 800 kPa, calcareous sand acoustic emission event rate decreased. The test of calcareous sand was divided into particle breakage stage and particle slip stage in low shear rate. Two stages can't be distinguished clearly as the shear rate increases. Loose and dense …

Random Noise Attenuation By Eemd In Common Offset Gathers, Shi Zhanzhan, Xia Yanqing, Zhou Huailai, Chi Yuelong, Pang Su

Coal Geology & Exploration

There are two problems in the random noise attenuation in f-x domain:(1) Reflected waves as hyperbolic events in pre-stack CMP gather or shot gathers, de-noising will damage the effective wave; (2) Seismic signals are complex non-stationary signals, requiring that the de-noising method has the adaptivity. Aiming at these two problems, a random noise suppression method based on f-x EEMD was proposed. The method utilizes the reflected waves which are horizontal events in common offset gathers, satisfying the f-x domain de-noising assumption, and the good adaptability of EEMD algorithm to non-stationary signals. For each frequency …

Analysis On Influence Of Ground Transmitting Electrode On Bidirectional Em-Mwd Signal Transmission Based On Ansys, Shao Chun, Han Jian, Chu Zhiwei, Xu Lin

Coal Geology & Exploration

The grounded emitter electrode is a necessary component of the bidirectional EM-MWD signal downlink system, and its reasonable parameter setting can improve the signal downlink effect, but at present, little is known about its influence on the downlink signal. This paper is based on the bi-directional EM-MWD working mechanism, combined with the current field theory, using ANSYS finite element software, establishes a three-dimensional simulation model of bidirectional EM-MWD signals, and analyzes the emission distance, length, diameter and resistivity of the ground transmitting electrode versus the downlink signal. The simulation results show that the downlink signal reception effect is positively correlated …

Elastic Wave Prestack Reverse Time Migration On Undulating Surfac, Liu Yang, Zhao Hu, Yin Cheng, Wu Sihai, Dai Ronghuo, Di Zhixin

Coal Geology & Exploration

At present, seismic exploration is facing many challenges in the "double complex" area, especially the undulating surface make it difficult to accurately image the underground complex structures. In this paper, we have studied the elastic wave prestack reverse time migration method for undulating surface, and a simple and effective treatment method was adopted to solve the free boundary conditions of undulating surface. In addition, the storage strategy of the effective boundary was used to solve the problem of big storage of elastic wave prestack reverse time migration. The numerical experimental results also show that this method can accurately reconstruct the …

Influence Mechanism Of Hard Brittle Abrasive On The Drilling Performance Of Impregnated Diamond Bit, Wang Jialiang, Wei Wenjie, Zhang Shaohe, Peng Fenfei

Coal Geology & Exploration

In order to improve the performance of diamond bit, impregnated diamond bit was prepared by adding different mass of hard brittle abrasive into matrix and drilling performance was tested by drilling experiments. The effect of hard brittle abrasive on drilling performance was studied. The results show that adding 5.5% SiC particle had better effect and the drilling efficiency increased by 55.14% compare with common bit. The hard brittle abrasive in the matrix can improving the microstructure of bit. The hard brittle abrasive left in the down hole can improve the erosion performance of washing fluid to matrix and increase the …

Finite Element 2d Forward Modeling Of Dc Method With Line Source, Xie Haijun, Li Zhiqiang, Li Sheng

Coal Geology & Exploration

In direct current prospecting, the forward calculation of 3D point source is complex and the calculation quantity is large, and using the Fourier transform can converted into 2D point source, but it is more complicated than that of 2D line source. This paper is based on Matlab programming, using the first boundary condition, and gives numerical solution of two-dimensional finite element of DC method with line source, through comparing with theoretical value of homogeneous half-space, the correctness of calculation results was verified. Then the high and low resistivity geoelectric models were built, the response of single side power supply and …

The Research Progress And Work Prospect Of Special Purpose Coal, Qiao Junwei, Ning Shuzheng, Qin Yunhu, Zhang Ning, Li Congcong, Zhang Jianqiang, Wei Yingchun, Zhu Shifei, Zhu Kaijia

Coal Geology & Exploration

Based on the refined geological exploration of coal, the clean and efficient use of coal, this paper reviews the implications of scarce coal and special purpose coal in previous studies. It was pointed out that special purpose coal is based on clean and efficient use of coal for coal resources with special industrial applications. The main types of coal are liquefaction coal, gasification purpose coal, coking coal and special high-element coal. Based on the coal quality evaluation of coal and the use of coal graded quality, this paper has sorted out the key evaluation indicators and evaluation parameters of special …

Technology And Practice For Deep Cbm Fracturing In Eastern Ordos Basin, Wang Xuxing, Wang Xingzun, Guo Bumin, Yuan Zheng, Feng Qing

Coal Geology & Exploration

The resources of deep coalbed methane buried at depth of more than 1 200 m in the eastern Ordos basin are rich and the key point for further exploration and development of CBM in the future. Compared with shallow CBM fracturing, there are many challenges in deep CBM fracturing such as with high situ stress, high closure stress, breakdown pressure as well as complex mechanical parameters of rock. Combined with the existing practice of CBM fracturing, taking the deep CBM buried at depth of about 2 000 m in the eastern Ordos basin as an example, tubing+ circulating SSD +packer …

Application Of Improved Hierarchic Analytic Process In The Classification Of Mine Hydrogeological Types, Wang Tiantian, Jin Dewu, Yang Jian, Liang Xiangyang

Coal Geology & Exploration

The classification of mine hydrogeological type is an important part of mine hydrogeology work. It is of great significance to analyze water filling conditions, evaluate water hazard and guide mine water prevention work. In order to evaluate mine hydrogeological conditions, this paper introduced optimal transfer matrix to improve hierarchic analytic process, and then applied this method to classify mine hydrogeological types. Taking four pairs of active mines in Hujierte mining area of Inner Mongolia as an example, the evaluation index system for classification of mine hydrogeological types was built on the basis of analysis of the hydrogeological conditions, then theoretical …

Design And Application Of Drilling Rod Vibration Frequency Measurement System, Liu Naipeng, Hu Yule, Wang Wei

Coal Geology & Exploration

During drilling, resonance is generated when the natural frequency of the drilling rod is consistent with the external excitation frequency. This will cause fatigue-failure of the drilling rod and serious consequences. To avoid this, a drilling rod vibration measurement system based on Micro-Electro-Mechanical System was designed. This system uses the three-axis acceleration sensor to measure the acceleration of the drilling rod in three directions. The upper computer software written in LabVIEW can storage, upload, display and process data. Then the fast Fourier Transform was taken to analyze the vibration frequency of the drilling rod. Finally the system is installed on …

Elastic Mechanics Solution Of Water Proof Key Layer In Coal Seam Floor Under High Water Pressure, Wang Yan, Yao Duoxi, Lu Haifeng

Coal Geology & Exploration

Aiming at the problem of water resisting capacity of the key layer in seam floor under the action of high pressure water, the key stratum was simplified as a fixed beam. The stress and displacement were calculated by the stress function method and the semi inverse method respectively. The results of two calculations were compared with the FLAC^3D results. The results show that the stress and displacement obtained by the stress function method are more appropriate than those calculated by the FLAC^3D method. It is suggested that for elastic mechanics analytic method of the fixed beam of the …

Integrated Identification Of Sequence Boundary Through Outcrop, Seismic With Logging And Geochemistry: A Case Of Jurassic In Northeastern Margin Of Ordos Basin, Zhang Tianfu, Zhang Yun, Cheng Yinhang, Miao Peisen, Ao Cong, Jin Ruoshi, Duan Lianfeng, Duan Xiaolong

Coal Geology & Exploration

Jurassic strata is mainly rock series containing coal and uranium in Ordos basin. The recognition of Jurassic sequence interfaces were mainly relied on the field outcrop, logging lithology of unconformity surface or the sedimentary discontinuity. However, it is tend to experience human recognition of randomness in the sequence interfaces recognition without macroscopic characteristics. Therefore, based on routine identification work such as outcrop profile and electrical curve of nearly 1 000 boreholes, combined with vertical changes of two-dimensional seismic profile and chemical index of alteration(CIA), three long-term cycle sequence interfaces(TSB1-TSB3) and seven medium-term cycle sequence interfaces(SB1-SB7) were finally identified in Jurassic …

Response Relation Between Fracturing Curve And Reservoir Pollution Degree Of Coalbed Methane Wells, Zhuang Dengdeng, Wang Yanbin, Tao Chuanqi, Chen Yan

Coal Geology & Exploration

In order to study the relationship between response curve and the pollution degree of fractured reservoir, taking Shizhuang block in Qinshui basin as an example, wells with different sensitivity of reservoir in the block were selected, through comparison of the difference of the dropping trace characteristics after the hydraulic curve reaches the fracture pressure in the fracturing curves of fracturing operation in different wells, the response law of hydraulic dropping trace and the reservoir sensitivity was summed up. Then in the same block according to the dropping trace of the hydraulic curves, the sensibility of reservoir was judged in several …

Tailings Dust Emissions, Emily Degner, Sam Horn, Zakary Galligan, Ryan Bernard, Julie Jameson, Josh Mueller, Natalie Tucker, Joe Griffin

Chemical Engineering Undergraduate Honors Theses

Fugitive dust emissions from the storage and handling of mine tailings presents environmental and safety concerns, which must be addressed to promote the land sustainability and the health and safety of individuals around a tailings storage facility (TSF). The investigated dust control methods were agglomeration, binder slurry injection, and topical spray.

The Dust Busters determined that pelletizing was the most practical method of agglomeration. In order to produce durable pellets from the mine tailings, which consist primarily of silica, a binder must be added. A variety of binders were considered including magnesium and calcium chloride, bentonite, barite, cement, vinyl polymers, …

Modeling Dynamic Community Acceptance Of Mining Using Agent-Based Modeling, Mark Kofi Boateng

Doctoral Dissertations

"This research attempts to provide fundamental understanding into the relationship between perceived sustainability of mineral projects and community acceptance. The main objective is to apply agent-based modeling (ABM) and discrete choice modeling to understand changes in community acceptance over time due to changes in community demographics and perceptions. This objective focuses on: 1) formulating agent utility functions for ABM, based on discrete choice theory; 2) applying ABM to account for the effect of information diffusion on community acceptance; and 3) explaining the relationship between initial conditions, topology, and rate of interactions, on one hand, and community acceptance on the other …

Haul Truck Tires Recycling, Jessica N. Lizarazu

Chemical Engineering Undergraduate Honors Theses

The disposal of large Off-the-Road (OTR) tires is an increasingly important concern. These tires can weigh up to 8,450 pounds with an overall diameter and width of approximately 140.7 inches and 45.1 inches respectively. OTR tires are used for mining vehicles such as haul trucks, wheel loaders, backhoes, graders, and trenchers. These new tires cost between $38,000 and $50,000 each, depending on multiple factors including oil prices and the cyclical nature of the industry. Haul trucks contain six tires per vehicle, and mines replace these tires around every 9-12 months. Statistics regarding discarded OTR tires are not provided by the …