Engineering Commons^™

Active Current Injection Method For Limiting Ground Fault Current Harmonics In Underground Coal Mines, Yigong Zhang

Theses and Dissertations--Mining Engineering

Current practice in U.S. underground coal mine high-voltage distribution systems is to attempt to limit ground fault current to 25 Amperes and de-energize the circuit at 10 Amperes. However, the significant amount of system capacitance due to the use of shielded cables can cause ground fault current to be two or three times the intended ground fault limit. Consequently, this practice can cause several issues such as ground fault currents significantly exceeding the neutral grounding resistor current limit, loss of relay selectivity in the distribution system, and transient overvoltages in certain ground fault situations. These issues are solved to some …

Distributional Fate Of Elements During The Synthesis Of Zeolites From South African Coal Fly Ash, Pieter W. Du Plessis, Tunde V. Ojumu, Ojo O. Fatoba, Richard O. Akinyeye, Leslie F. Petrik

Mining Engineering Faculty Research & Creative Works

The synthesis of zeolites from South African coal fly ash has been deemed a viable solution to the growing economical strain caused by the disposal of ash in the country. Two synthesis routes have been studied thus far namely the 2-step method and the fusion assisted process. Fly ash contains several elements originating from coal which is incorporated in the ash during combustion. It is vital to determine the final destination of these elements in order to unveil optimization opportunities for scale-up purposes. The aim of this study was to perform a material balance study on both synthesis routes to …

Ultra Clean Coal Production Using Dense Medium Separation For The Silicon Market, Seyed Hassan Amini

Theses and Dissertations--Mining Engineering

The production of high quality silicon requires the use of ultraclean coal containing less than 1.5% ash. The magnetite used to clean the coal in a dense medium process is a contaminant that seriously impacts the quality of the final silicon product. As such, research has been conducted to evaluate the potential to substitute the magnetite with fine silica–based alternative material generated during the silicon production process. Dense medium cyclone tests were performed based on a statistically designed program to determine the optimum conditions that maximize organic efficiency and minimize probable error and low–density bypass. The results revealed that a …

Status Of Communication And Tracking Technologies In Underground Coal Mines, Alexander D. Douglas

Theses and Dissertations--Mining Engineering

In 2006, Congress passed the MINER Act requiring mine operators to submit an emergency response plan that included post-accident communications and tracking systems to MSHA within three years of the Act. These systems were required to be designed for maximum survivability after a catastrophic event, such as a fire or explosion, and to be permissible (meets MSHA criteria for explosion-proof). At that time, no commercially available systems existed that met these standards. Several companies undertook developing new, or enhancing existing, technologies to meet these requirements. This research presents the results of a study that was conducted to determine the present …

Multiscale Modeling Of The Mine Ventilation System And Flow Through The Gob, William Chad Wedding

Theses and Dissertations--Mining Engineering

The following dissertation introduces the hazard of methane buildup in the gob zone, a caved region behind a retreating longwall face. This region serves as a reservoir for methane that can bleed into the mine workings. As this methane mixes with air delivered to the longwall panel, explosive concentrations of methane will be reached.

Computational fluid dynamics (CFD) is one of the many approaches to study the gob environment. Several studies in the past have researched this topic and a general approach has been developed that addresses much of the complexity of the problem. The topic of research herein presents …

Development Of Industry Oriented Cfd Code For Analysis / Design Of Face Ventilation Systems, Todor P. Petrov

Theses and Dissertations--Mining Engineering

Two of the main safety and health issues recognized during deep cut coal mining are methane and dust hazards. Advances in continuous miner technology have improved safety and productivity. However, these advances have created some environmental problems, notably more dust and methane being generated at the face during coal extraction.

Results of studies performed in the last three decades concerning the face ventilation for deep cut mining showed very complicated airflow behavior. The specifics of flow patterns developed by the face ventilation systems presents significant challenge for analytical description even for equipment-free entry. Fortunately, there are methods, such as numerical …

Fragmentation Analysis In The Dynamic Stress Wave Collision Regions In Bench Blasting, Catherine E. Johnson

Theses and Dissertations--Mining Engineering

The first step in many mining operations is blasting, and the purpose of blasting is to fragment the rock mass in the most efficient way for that mine site and the material end use. Over time, new developments to any industry occur, and design and implementation of traditional techniques have to change as a consequence. Possibly the greatest improvement in blasting in recent years is that of electronic detonators. The improvements related to safety and increased fragmentation have been invaluable. There has been ongoing debate within the explosives industry regarding two possible theories for this. Shorter timing delays that allow …

Evaluation Of Overpressure Wave Transition By Airblast Overpressure And Shock Wave Attenuation Analysis Using A Small Black Powder Charge, William R. Weitzel

Theses and Dissertations--Mining Engineering

Eight flush mount pressure sensors were used in a series of 3 test sequences to measure air overpressure produced by a firecracker. Overpressure was recorded at a range of 1 inch to 21 inches away from detonation, and charge weight was determined to be 0.1mg of black powder. Air overpressure prediction equations were developed from test series then compared to collected data for subsequent tests. Overpressure wave velocity was measured using wave arrival time and distance between sensors. This wave velocity was compared to calculated wave velocity using overpressure and ideal gas law. Overpressure and wave velocity are directly related …

Analysis Of A Ventilation Network In A Multiple Fans Limestone Mine, Ali Haghighat

Masters Theses

"As mining progresses the total resistance of an excavation is increased, the mine characteristic curve becomes steeper, and the operating point moves up the fan curve, reducing the total air quantity and increasing the system pressure. For multi-level ventilation networks with a number of fans the process can be tedious, and on a count of numerous dependent factors the optimal combination of fans is very hard to be achieved. The design of a ventilation network in conjunction with multi surface fans and booster fans entails a complex procedure.

The objective of this study is to provide a plan to improve …

Determining And Mitigating The Effects Of Firing A Linear Shaped Charge Under Water, Brian Burch

Masters Theses

"When fired under water, a Linear Shaped Charge (LSC) does not penetrate a steel target as well as in air. This lack of performance has been a problem for shaped charge manufacturers and their clients. It was obvious that this degradation of performance is due to water having a higher density than air and water being incompressible compared to air. This study aimed to better determine how the water was affecting the LSC and to provide a method of mitigation.

LSCs of different sizes were submerged under water and fired through the water with and without a target. It was …

The Effects Of Advanced Structural Materials To Mitigate Explosive And Impact Threats, Caleb Michael Baumgart

Masters Theses

"In a world of ever newer and modified improvised explosive devices (IEDs) that are very common in certain parts of the world, it is always more important to improve the devices used for protection. This research endeavors to design and analyze a blast barrier using three different media types to mitigate the high pressures from an IED or a car bomb. The three media types used in this research are pumice, steel grit, and foam. Six barriers were built to test the three media types and account for the changes from a standard solid concrete barrier to a barrier with …

Behavior In Air Leakage And Recirculation Under The Influence Of Booster Fans, Koziba Feledi

Masters Theses

"A booster fan is an underground mechanical ventilation equipment installed in series with a main surface fan that is used to boost the air pressure provided by the surface main fan passing through it. As mining continues to expand and go deeper, the need for improved and efficient ventilation increases. This has led to the use of booster fans and other auxiliary ventilation devices in underground mines. Research defining how system leakage and recirculation are affected by booster fans; describing how system leakage and recirculation are affected by the location, placement, and amount of air pressure from the booster fans; …

A Modified Initiation And Cut Profile Study Of The 10500 Grain Per Foot Linear Shaped Charge, Matthew Ortel

Masters Theses

"A 10,500 grain per foot (gr/ft.) linear shaped charge (LSC) was developed to cut targets that were too thick for smaller LSC. The manufacturer observed shallower penetration from the 10,500 gr/ft. LSC than was expected. This prompted investigations to uncover the cause of the perceived reduced performance.

A study performed at the Missouri University of Science and Technology changed the initiation method of the 10,500 gr/ft. charge to increase the cut performance of the charge. A modified two point, single end initiation method was devised and tested. This initiation method was termed "dual initiation" and focused on creating a planar …

Test Development To Determine The Feasibility Of Rubber Tractor Treads For Use As Blasting Mats, Matthew Kurtis Coy

Masters Theses

"The objective of this thesis was to determine if rubber tractor treads could be used as an alternative material for blasting mats. These treads are made from steel cable and vulcanized rubber and are very tough. However, once they reach the end of their life on mobile equipment, they are destined for a landfill, or dump site because they are too tough to recycle. A potential alternative use for them is as blasting mats.

An examination of existing mat designs was conducted to better understand the matting methods used by the blasting industry today, to learn from those designs allow …

Stability Analysis Of Bleeder Entries In Underground Coal Mines Using The Displacement-Discontinuity And Finite-Difference Programs, Xu Tang

Graduate Theses, Dissertations, and Problem Reports (ETD)

The stability of bleeder entries is essential for both mine ventilation and personnel travelling through the entries. Therefore, it is imperative that bleeder pillars remain stable and bleeder entries safe during their service life. Surprisingly, there are few published investigations on ground control issues in the bleeder entries. This thesis is an attempt to analyze the ground control problems in bleeder entries especially, the structural integrity of the bleeder entry. Two numerical programs (a) displacement discontinuity program-LaModel and (b) the finite difference program-FLAC were used to investigate these problems. Modeling results from the LaModel program indicated that the vertical stresses …

La Yeguada Volcanic Vomplex In The Republic Of Panama: An Assessment Of The Geologic Hazards Using 40ar/39ar Geochronology, Karinne L. Knutsen, William I. Rose, Brian Jicha

Department of Geological and Mining Engineering and Sciences Publications

La Yeguada volcanic complex is one of three Quaternary volcanic centers in Panama. To assess potential geologic hazards, new samples were analyzed using argon analysis (⁴⁰Ar/³⁹Ar), and obtained the following: the most recent eruption occurred approximately 32,000 years ago at the Media Luna cinder cone; the youngest dated eruption from the main dome complex occurred 357 ± 19 ka, producing the Castillo dome unit; Cerro Picacho, a separate dacite dome 1.5 km east of the main complex is 4.47 ± 0.23 Ma; and the El Satro Pyroclastic Flow unit surrounds the northern portion of the volcanic …

Method For Coating Mineral Granules To Improve Bonding To Hydrocarbon-Based Substrate And Coloring Of Same, Bowen Li, Ralph Hodek, Domenic Popko, Jiann-Yang Hwang

Michigan Tech Patents

Provided are compositions comprising stamp sand granules embedded in asphalt, where the stamp sand granules comprise a silane coating. Additionally provided are methods of making a silane-coated stamp sand, the methods comprising combining stamp sand granules and a silane solution to form a mixture and drying the mixture. Additionally provided are methods of covering a surface, the methods comprising combining silane-coated particles and asphalt to provide a mixture and distributing the mixture on the surface.

Projected Effect Of 2000-2050 Changes In Climate And Emissions On Aerosol Levels In China And Associated Transboundary Transport, H. Jiang, H. Liao, H. O.T. Pye, S. Wu, L. J. Mickley, J. H. Seinfeld, X. Y. Zhang

Michigan Tech Publications, Part 1

We investigate projected 2000-2050 changes in concentrations of aerosols in China and the associated transboundary aerosol transport by using the chemical transport model GEOS-Chem driven by the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 3 at 4° × 5° resolution. Future changes in climate and emissions projected by the IPCC A1B scenario are imposed separately and together through sensitivity simulations. Accounting for sulfate, nitrate, ammonium, black carbon (BC), and organic carbon (OC) aerosols, concentrations of individual aerosol species change by -1.5 to +0.8 μg m-3, and PM2.5 levels are projected to change by about 10-20% in eastern …

Laboratory Study On The Mobility Of Major Species In Fly Ash-Brine Co-Disposal Systems: Up-Flow Percolation Test, O. O. Fatoba, L. F. Petrik, R. O. Akinyeye, W. M. Gitari, E. I. Iwuoha

Mining Engineering Faculty Research & Creative Works

Apart from the generation of fly ash, brine (hyper-saline wastewater) is also a waste material generated in South African power stations as a result of water re-use. These waste materials contain major species such as Al, Si, Na, K, Ca, Mg, Cl and SO4. The co-disposal of fly ash and brine has been practiced by some power stations in South Africa with the aim of utilizing the fly ash to capture the salts in brine. The effect of the chemical interaction of the species contained in both fly ash and brine, when co-disposed, on the mobility of species in the …

The Size Range Of Bubbles That Produce Ash During Explosive Volcanic Eruptions, Kimberly Genareau, Gopal K. Mulukutla, Alexander A. Proussevitch, Adam J. Durant, William I. Rose, Dork L. Sahagian

Department of Geological and Mining Engineering and Sciences Publications

Volcanic eruptions can produce ash particles with a range of sizes and morphologies. Here we morphologically distinguish two textural types: Simple (generally smaller) ash particles, where the observable surface displays a single measureable bubble because there is at most one vesicle imprint preserved on each facet of the particle; and complex ash particles, which display multiple vesicle imprints on their surfaces for measurement and may contain complete, unfragmented vesicles in their interiors. Digital elevation models from stereo-scanning electron microscopic images of complex ash particles from the 14 October 1974 sub-Plinian eruption of Volcán Fuego, Guatemala and the 18 May 1980 …

Impact Of Aging Mechanism On Model Simulated Carbonaceous Aerosols, Y. Huang, S. Wu, M. K. Dubey, N. H.F. French

Michigan Tech Publications, Part 1

Carbonaceous aerosols including organic carbon and black carbon have significant implications for both climate and air quality. In the current global climate or chemical transport models, a fixed hydrophobic-to-hydrophilic conversion lifetime for carbonaceous aerosol (τ) is generally assumed, which is usually around one day. We have implemented a new detailed aging scheme for carbonaceous aerosols in a chemical transport model (GEOS-Chem) to account for both the chemical oxidation and the physical condensation-coagulation effects, where τ is affected by local atmospheric environment including atmospheric concentrations of water vapor, ozone, hydroxyl radical and sulfuric acid. The updated τ exhibits large spatial and …

Quantifying The Impact Of Boreal Forest Fires On Tropospheric Oxidants Over The Atlantic Using Aircraft And Satellites (Bortas) Experiment: Design, Execution And Science Overview, P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, R. C. Owen, Et. Al.

Michigan Tech Publications, Part 1

We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned …

Energy, U.S. Department Of, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides information about the U.S. Department of Energy (DOE) and its predecessor agencies and how DOE influences federal energy policy and scientific research in the western U.S.

Mining, Uranium, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of uranium mining's role and influence in the American West with comparative information on uranium mining in foreign countries.

Modeling Of 2008 Kasatochi Volcanic Sulfate Direct Radiative Forcing: Assimilation Of Omi So2 Plume Height Data And Comparison With Modis And Caliop Observations, J. Wang, S. Park, J. Zeng, C. Ge, K. Yang, S. Carn, N. Krotkov, A. H. Omar

Michigan Tech Publications, Part 1

Volcanic SO2 column amount and injection height retrieved from the Ozone Monitoring Instrument (OMI) with the Extended Iterative Spectral Fitting (EISF) technique are used to initialize a global chemistry transport model (GEOS-Chem) to simulate the atmospheric transport and lifecycle of volcanic SO2 and sulfate aerosol from the 2008 Kasatochi eruption, and to subsequently estimate the direct shortwave, top-of-the-atmosphere radiative forcing of the volcanic sulfate aerosol. Analysis shows that the integrated use of OMI SO2 plume height in GEOS-Chem yields: (a) good agreement of the temporal evolution of 3-D volcanic sulfate distributions between model simulations and satellite observations from the Moderate …

Comparison Between Neural Networks And Multiple Regression Methods In Metallurgical Performance Modeling Of Flotation Column, Fardis Nakhaei, Mehdi Irannajad

Mining Engineering Faculty Research & Creative Works

Artificial neural networks are relatively new computational tools which their inherent ability to learn and recognize highly non-linear and complex relationships makes them ideally suited in solving a wide range of complex real-world problems. In this research, different techniques (Linear regression, Non-linear regression, Back propagation neural network, Radial Basis Function for the estimation of Cu grade and recovery values in flotation column concentrate are studied. Modeling is performed based on 90 datasets at different operating conditions at Sarcheshmeh pilot plant, a copper concentrator in Iran, which include chemical reagents dosage, froth height, air and wash water flow rates, gas holdup …

Validation Of The Fall3d Model For The 2008 Chaitén Eruption Using Field And Satellite Data, María Soledad Osores, Arnau Folch, Estela Collini, Gustavo Villarosa, Adam J. Durant, Gloria Pujol, José G. Viramonte

Michigan Tech Publications, Part 1

The 2008 Chaitén Volcano eruption began on 2 May 2008 with an explosive phase that injected large amounts of tephra into the atmosphere. During the first week of the eruption, volcanic ash clouds were transported for hundreds of kilometres over Argentina by the prevailing westerly winds. Tephra deposition extended to the Atlantic Ocean and severely affected the Argentinean Patagonia. Impacts included air and water quality degradation, disruption of ground transportation systems and cancellation of flights at airports more than 1,500 km apart. We use the FALL3D tephra transport model coupled with the Weather Research and Forecasting-Advanced Research Weather (WRF-ARW) meteorological …

Power And Politics In Organizations, Thomas W. Camm

Mining Engineering

Aristotle made the observation that man is a political animal. Engineers often like to think they are above the fray when it comes to organizational politics, but most organizational theorists believe politics is a fundamental dynamic in any group. This paper examines the various ways that people use power within organizations to negotiate the political interactions in the work place.

Nanobubble Column Flotation For More Efficient Coal Recovery, Ahmed Sobhy, R. Honaker, D. Tao

Mining Engineering Faculty Research & Creative Works

Froth flotation is a widely used, cost effective coal cleaning process. However, its high process efficiency is limited to a narrow particle size range between approximately 50 to 600 μm for coal and 10 to 100 μm for minerals. Beyond this range, the efficiency of froth flotation decreases sharply, especially for difficult-to-float coal fines of weak hydrophobicity (e.g., oxidized coal).

This study was aimed at enhancing recovery of an Illinois fine coal sample using a flotation column featuring a hydrodynamic cavitation nanobubble generator. Nanobubbles that are mostly smaller than 1 μm can be formed selectively on hydrophobic coal particles from …

Nonlinear Granger Causality And Its Application In Decoding Of Human Reaching Intentions, Mengting Liu

Doctoral Dissertations

Multi-electrode recording is a key technology that allows the brain mechanisms of decision making, cognition, and their breakdown in diseases to be studied from a network perspective. As the hypotheses concerning the role of neural interactions in cognitive paradigms become increasingly more elaborate, the ability to evaluate the direction of neural interactions in neural networks holds the key to distinguishing their functional significance.

Granger Causality (GC) is used to detect the directional influence of signals between multiple locations. To extract the nonlinear directional flow, GC was completed through a nonlinear predictive approach using radial basis functions (RBF). Furthermore, to obtain …