Mining Engineering Commons^™

Reliability Analysis For Mine Blast Performance Based On Delay Type And Firing Time, Jhon Silva-Castro, Lifeng Li, Jeremy M. Gernand

Mining Engineering Faculty Publications

Mining blasts may be defined as the use of explosive charges in a controlled manner by following a tightly controlled timing sequence according to an assigned firing order. Changes of timing between charges may result in an altered firing order and failure of the blasting sequence, which can cause high vibration levels, poor fragmentation, and/or an undesirable rock mass movement direction. Despite the importance of timing in determining mine blast results, there exists a lack of methodologies or tools with which to assess performance of a complete blast based on delay type and timing sequence. This document applies reliability engineering …

Montana Tech's Underground Mine Education Center, Scott Rosenthal, Pete Knudsen

Mining Engineering

SME Annual Meeting, Feb. 24-27, 2018, Denver, CO. Preprint 19-057.

Discusses development and use of the Montana Tech Underground Mine Education Center (UMEC).

Focus Energy Determination Of Mining Microseisms Using Residual Seismic Wave Attenuation In Deep Coal Mining, Mingwei Zhang, Shengdong Liu, Shuzhao Chen, Yanlong Chen, Guang Xu, Deyu Qian

Mining Engineering Faculty Research & Creative Works

Based on the energy attenuation characteristics of residual wave in deep rock, a method was developed to determine the microseismic focus energy. Differential energy loss in infinitesimal spreading distance is logically deduced, upon which energy attenuation equation was established. With a logarithmic transformation, a linear relation of the residual seismic energy with distance is formulated. Its intercept was used to determine the microseismic focus energy. The result is compared with that determined by the energy density method. The reliability of the determined focus energy and the impact of the built-in velocity threshold on the residual wave energy computation are discussed. …

Using Lamodel To Analyze Coal Bumps, Keith A. Heasley, Ihsan Berk Tulu

Faculty & Staff Scholarship

Coal bumps have long been a safety hazard in coal mines, and even after decades of research, the exact mechanics that cause coal bumps are still not well understood. Therefore, coal bumps are still difficult to predict and control. The LaModel program has a long history of being used to effectively analyze displace- ments and stresses in coal mines, and with the recent addition of energy release and local mine stiffness calculations, the LaModel program now has greatly increased capabilities for evaluating coal bump potential. This paper presents three recent case histories where coal stress, pillar safety factor, energy release …

Numerical Analysis And Case Study On The Mitigation Of Mining Damage To The Floor Of No. 5 Coal Seam Of Taiyuan Group By Grouting, A. Li, Y. Liu, L. Mou, K. Li

Faculty & Staff Scholarship

Based on the geological condition of panel 22507 of the no. 5 coal seam at Dongjiahe coal mine, numerical analysis of the stability and water permeability of the floor aquiclude before and after grouting was conducted using Rock Failure Process Analysis (F-RFPA2D). The dynamic development, extension, and distribution of the cracks in the aquiclude are discussed. It is shown that grouting can increase the effective thickness of the aquiclude, reduce the floor damage depth, and control the floor water inrush path, thus effectively improving the overall strength and water blocking capability of the aquiclude. These numerical study results were applied …

Dynamic Mechanical Behavior Of Dry And Water Saturated Igneous Rock With Acoustic Emission Monitoring, Jun Guo, Guo-Rui Feng, Ting-Ye Qi, Pengfei Wang, Jian Yang, Zhen Li, Jinwen Bai, Xianjie Du, Zehua Wang

Faculty & Staff Scholarship

The uniaxial cyclic loading tests have been conducted to study the mechanical behavior of dry and water saturated igneous rock with acoustic emission (AE) monitoring. The igneous rock samples are dried, naturally immersed, and boiled to get specimens with different water contents for the testing. The mineral compositions and the microstructures of the dry and water saturated igneous rock are also presented. The dry specimens present higher strength, fewer strains, and rapid increase of AE count subjected to the cyclic loading, which reflects the hard and brittle behavior and strong burst proneness of igneous rock. The water saturated specimens have …

Geotechnical Considerations For Concurrent Pillar Recovery In Close-Distance Multiple Seams, Peter Zhang, Berk Tulu, Morgan Sears, Jack Trackemas

Faculty & Staff Scholarship

No abstract provided.

Analysis Of Global And Local Stress Changes In A Longwall Gateroad, I.B. Tulu, G.S. Esterhuizen, D. Gearhart, T.M. Klemetti, K.M. Mohamed, D.W.H. Su

Faculty & Staff Scholarship

A numerical-model-based approach was recently developed for estimating the changes in both the hor- izontal and vertical loading conditions induced by an approaching longwall face. In this approach, a sys- tematic procedure is used to estimate the model’s inputs. Shearing along the bedding planes is modeled with ubiquitous joint elements and interface elements. Coal is modeled with a newly developed coal mass model. The response of the gob is calibrated with back analysis of subsidence data and the results of previously published laboratory tests on rock fragments. The model results were verified with the sub- sidence and stress data recently …

Vertical Stress And Stability Of Interburden Over An Abandoned Pillar Working Before Upward Mining: A Case Study, Jinwen Bai, Guorui Feng, Shanyong Wang, Tingye Qi, Jian Yang, Jun Guo, Zhen Li, Xianjie Du, Zehua Wang, Yunlou Du, Yujiang Zhang

Faculty & Staff Scholarship

Upward mining of the residual coal seam over an abandoned pillar working is one of the effective measures to alleviate the contradiction between limited resources and increased consumption. Interburden stability over an abandoned pillar working plays a significant role in guaranteeing the safety of upward mining; however, it has not yet been extensively studied and understood. In this study, the vertical stress of the interburden over an abandoned pillar working was first investigated. The mechanical model of the interburden was established and the damage conditions were analysed. Then, the stability of the interburden over 38502 abandoned workings in Baijiazhuang coal …

Analysis Of Monitored Ground Support And Rock Mass Response In A Longwall Tailgate Entry, G.S. Esterhuizen, D.F. Gearhart, I.B. Tulu

Faculty & Staff Scholarship

A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West Virginia. Monitoring was initiated a few days after development of the gateroad entries and continued during passage of the longwall panels on both sides of the entry. Monitoring included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation, stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring …

Deep Cover Bleeder Entry Performance And Support Loading: A Case Study, Ted M. Klemetti, Mark Alexander Van Dyke, Ihsan Berk Tulu

Faculty & Staff Scholarship

Several questions have emerged in relation to deep cover bleeder entry performance and support loading: how well do current modeling procedures calculate the rear abutment extent and loading? Does an improved understanding of the rear abutment extent warrant a change in standing support in bleeder entries? To help answer these questions and to determine the current utilization of standing support in bleeder entries, four bleeder entries at varying distances from the startup room were instrumented, observed, and numerically modeled. This paper details observations made by NIOSH researchers in the bleeder entries of a deep cover longwall panel—specifically data collected from …

Impact Of Nanobubbles On Mechanical Coal Flotation Process, Ahmed Sobhy, Dongping Tao

Mining Engineering Faculty Research & Creative Works

A bank of three 10-liter mechanical flotation cells integrated with nanobubble technology was investigated to assess the impact of nanobubbles on coal separation performance at different operating variables. The most significant operation parameters such as fuel oil collector dosage, methyl isobutyl carbinol (MIBC) frother concentration, flow rate to nanobubble generator, feed solid concentration, and feed flow rate were studied individually. Nanobubbles are generated selectively on the hydrophobic particles, which should have a positive effect on flotation separation efficiency. It has been shown that frother concentration, collector dosage, and flow rate to nanobubble generator had a positive and significant effect on …

Dust Control Examination Using Computational Fluid Dynamics Modeling And Laboratory Testing Of Vortecone And Impingement Screen Filters, Ashish R. Kumar

Theses and Dissertations--Mining Engineering

Heavy industries, such as mining, generate dust in quantities that present an occupational health hazard. Prolonged exposure to the respirable dust has been found to result in many irreversible occupational ailments in thousands of miners. In underground mining applications, a variety of scrubbing systems are used to remove dust near the zones of generation. However, the wire-mesh type fibrous screens in the flooded-bed dust scrubbers used on continuous miners, are prone to clogging due to the accumulation of dust particles. This clogging results in a reduced capture efficiency and a higher exposure to the personnel. This research establishes the Vortecone, …

Assessment Of The Physical And Chemical Qualities Of Brine And The Application Of Nano Zerovalent Iron For The Treatment Of Brine Effluent, M. J. Alegbe, O. S. Ayanda, P. Ndungu, O. O. Fatoba, A. Nechaev, L. F. Petrik

Mining Engineering Faculty Research & Creative Works

The arbitrary discharge of brine effluent from reverse osmosis treatment plants impacts negatively to the environment due to its high salinity. In the present study, brine effluent obtained from eMalahleni treatment plant, South Africa, was analyzed by pH, electrical conductivity and total dissolved solids measurements. The ion chromatography and the inductively coupled plasma optical emission spectroscopy were also used to examine the anion and cation content of the brine effluent. The analysis of major cations and anions indicated that the brine water quality was above the target water quality range for potable water. Geochemical modelling of the brine effluent classified …

Evaluation And Prevention Of Spontaneous Combustion During Handling And Storage Of Coal, Amir E. Najarzadeh

Theses and Dissertations--Mining Engineering

Spontaneous combustion of coal has historically been a major problem for the coal industry, predominantly during storage and transportation. Various methods have been used in the laboratory for evaluating the propensity of different coal sources to self-heat. However, the heterogeneity of coal and the complexity of the system has resulted in inconsistencies and sometimes conflicting results as indicated by the findings reported in several publications.

The primary objective of the current study was to build a laboratory scale apparatus that simulates the condition of a coal stockpile to evaluate the events leading to spontaneous combustion and develop potential remedies. As …

Investigation Of The Effectiveness Of An Integrated Flooded-Bed Dust Scrubber On A Longwall Shearer Through Laboratory Testing And Cfd Simulation, Sampurna N. Arya

Theses and Dissertations--Mining Engineering

Dust generation at an underground coal mine working face continues to be a health and safety issue. Prolonged exposure to high concentrations of airborne respirable dust can cause a debilitating and often fatal respiratory disease called Black Lung. In addition, the deposition of float dust in mine return airways poses a serious safety hazard if not sufficiently diluted with inert rock dust. A localized methane explosion can transition into a self-propagating dust explosion. Since dust is a byproduct of various mining activities, such as cutting and loading, crushing, and transportation, the dust-related issues cannot be totally eliminated. However, the adverse …

Investigation Of Environmental Cadmium Sources In Eastern Kentucky, Elizabeth Maher

Theses and Dissertations--Mining Engineering

Utilizing data collected by the University of Kentucky Lung Cancer Research Initiative (LCRI), this study investigated potential mining-related sources for the elevated levels of cadmium in Harlan and Letcher counties. Statistical analyses for this study were conducted utilizing SAS. A number of linear regression models and logarithmic models were used to evaluate the significance of the data. The linear regression models consisted of both simple and multivariate types, with the simple models seeking to establish significance between the potential sources and urine cadmium levels and the multivariate models seeking both to identify any statistically significant linear relationships between source types …

Numerical Analysis Of Stress Distributions For Multiple Backfilled Stopes, Christopher Richard Newman

Theses and Dissertations--Mining Engineering

Over the past three decades, technological innovations with respect to cemented paste backfill (CPB) as a means of ground support has allowed for increased production within the mining industry, management mine waste costs, as well as the improvement of the overall health and safety of underground mining operations. Despite the extensive use of this relatively new ground support material, many fundamental factors affecting the design of safe and economical CPB structures are still not well understood.Recently, a significant amount of academic and industry research has been conducted to better understanding the distribution of stress with respect to primary-secondary extraction sequencing …

Analysis Of Underground Coal Mine Structures Subjected To Dynamic Events, Brooklynn Yonts

Theses and Dissertations--Mining Engineering

Underground coal mine explosions pose a significant threat to infrastructure such as mine seals and refuge alternative chambers. After a mine seal failed in the Sago mine disaster, which took the life of 12 miners, design requirements were reexamined and improved. However, most research being completed on the analysis of mine structures during an explosive event focuses solely on peak pressure values, while ignoring the impact of pressure duration. This study investigates the impact pressure duration, waveform shape, and impulse have on structural displacement, while also exploring what pressures and duration can be expected during a mine explosion. Additionally, the …

Synthesis Of Single-Hole Vibration Waveforms From A Mining Blast, Lifeng Li

Theses and Dissertations--Mining Engineering

In mining engineering, blast-induced ground vibration has become one of the major concerns when production blasts are conducted, especially when the mining areas and the blast sites are near inhabited areas or infrastructure of interest. To comply with regulations, a vibration monitoring program should be developed for each mining operation. The vibration level, which is usually indicated by the peak particle velocity (PPV) of the vibration waveform, should fall below the maximum allowable values. Ideally, when blasting is near structures of interest (power towers, dams, houses, etc.), the vibration level (PPV) should be predicted prior to the actual production blasts. …