Engineering Commons^™

Static And Dynamic Discrete Element Modelling Of Slender Coal Pillars, Michael J. Raffaldi

Theses and Dissertations--Mining Engineering

Highwall mining is a mining method used in surface coal operations that involves driving a series of parallel entries into the exposed coal seam at the highwall face under an unsupported roof leaving behind a series of long, but very slender coal pillars. Highwall mining often occurs simultaneously with production blasting taking place in other areas of the mine. Although no failures of highwall pillars have been attributed to nearby blasting, numerical modelling presents an inexpensive means of investigating the possible effects of strong ground motion on the stability of these pillars. This thesis documents the development of a discrete …

Improved Understanding Of Coal Pillar Behavior And Bump Potential Through The Ground Response Curve, Kevin W. Harris

Theses and Dissertations--Mining Engineering

Continued depletion of easier coal reserves has necessitated development at deeper overburdens. At greater depth, operations often encounter more difficult ground conditions due to higher stresses and potential multiple seam interactions. Pillars which are left intact as the primary support mechanism experience an increase in loading. Mine design improvements are often incorporated to combat increased loads, principally by increasing pillar size. However, the potential for coal bumps, which are a rapid and violent failure of coal pillars, has increased due to these higher stresses and the use of larger width-to-height (W/H) ratio pillars.

Many efforts have been made to predict …

Microstructure And Geotechnical Properties Of St. Peter Sandstone In Clayton, Iowa, Amir Hossein Bagherieh

Doctoral Dissertations

"The St. Peter Sandstone is significantly different from the minerals and rocks which have been studied extensively in mining. It is brittle and characterized by an unusually high friction angle. On the other hand it is friable, and it is nearly cohesionless. The scarcity of the ground control techniques for this particular mining environment has created many difficulties for mine operators. This research aims to establish a fundamental understanding of the basic mechanical and strength properties of the St. Peter Sandstone for engineering design and scientific research. The specific objectives are 1) characterizing the strength of the St. Peter Sandstone, …

The Effects Of Physical Flash Hole Deviations On Factory-Grade Rifle Ammunition, Nicolaas Martin Schrier

Masters Theses

"The objective of this research is to determine the effect of dimensional and positional changes of the primer flash hole on the performance of factory-grade rifle ammunition. The studied variables were flash hole diameter, offset from center, and orientation of the offset in the primer pocket. Cartridge performance was quantified by measuring muzzle velocity, chamber pressure, and target grouping size (precision).

Five different flash hole diameters were tested for both the Remington .223 and Winchester .308 calibers: 1.4mm, 2.0mm (the Fiocchi standard), 2.4mm, 2.8mm, and 3.0mm. Each diameter was tested at three offsets: centered (no offset), 0.5mm from center, and …

Detecting Diesel Particulate Matter Using Real Time Monitoring Under The Influence Of An Exhaust Fan System, Yasir Helal Alghamdi

Masters Theses

"Diesel Particulate Matter (DPM) is a complex mixture of diesel exhaust gas that consists of carbon, ash, metallic abrasion particles, sulfates and silicates. The diesel soot particle includes a solid core made of elemental carbon, and organic carbon compound attached to the surface of the soot particle. The main source of DPM is diesel exhaust gas. The National Institute for Occupational Safety and Health (NIOSH) and the Environmental Protection Agency (EPA) have determined that DPM is the source of most of the emissions of carbon monoxide, carbon dioxide, oxide of nitrogen, and hydrocarbons in underground coal, metal and non metal …

The Effects Of Short Delay Times On Rock Fragmentation In Bench Blasts, Margaret Ruth Hettinger

Masters Theses

"Optimized rock fragmentation is essential for minimizing downstream costs to mining operations. Photographic fragmentation analysis, vibration monitoring, and high-speed video all provide measurements of blast effectiveness and supply data that allows operations to modify blasts to achieve downstream goals.

This study evaluates the effects of short hole-to-hole delay times on rock fragmentation. Photographic fragmentation analysis and various delay times were used on the same bench blast, the effects of timing on fragmentation were determined. This analysis provides a representative understanding of timing effects on fragmentation in the field, different from previous blast models which either negate the effects of timing …

Studies On The Role Of Organic-Inorganic Hybrid Polyacrylamides In Fine Coal Flotation, Ontlametse Kenneth Molatlhegi

Masters Theses

"The current study investigated the effect of novel organic/inorganic (hybrid) polyacrylamide polymer as ash (slimes) depressant in fine coal flotation for the possibility to enhance the combustible recovery and ash rejection. Raw coal samples contain about 25% of ash-forming minerals were crushed, grinded to -75um and floated in the presence of in-house synthesized hybrid Polyacrylamide (Al(OH)₃-PAM or Al-PAM) at different operational parameters. Denver flotation cell with a 5-Liters capacity was used and the parameters investigated include: Al-PAM dosage, Al-PAM conditioning time, dual use of Al-PAM and a dispersant, impeller rotation speed and pulp's pH. For comparison purposes, commercially …

The Impact Of A Strong Local Supply Chain On Regional Economic Impacts Of Mining, Meiyu Xing

Masters Theses

"With growing social conflicts due to social and environmental concerns mines need to be able to create shared value for all stakeholder in their quest to promote sustainable development. Given the sensitivity of a mine's regional economy contribution to its supply chains, any improvement in supply chains strategy will be beneficial for mines and their stakeholders. The objectives of this work were to: (i) test the hypothesis that supply chain management strategy, by mines in a region, significantly affects regional economy; and (ii) develop a methodology to identify the critical backward commodities of a regional mining sector.

Valid methods have …

The Dispersion And Selective Flocculation Of Hematite Ore, Howard James Haselhuhn Iii

Dissertations, Master's Theses and Master's Reports - Open

Iron ore is one of the most important ores in the world. Over the past century, most mining of iron ore has been focused on magnetite (Fe3O4). As the name suggests, magnetite is magnetic in nature and is easily separated from gangue (unwanted) minerals through magnetic separation processes. Unfortunately, the magnetite ore bodies are diminishing. Because of this, there has been a recent drive to pursue technology that can economically separate hematite (Fe2O3) from its gangue minerals as hematite is a much more abundant source of iron. Most hematite ore has a very small liberation size that is frequently less …

Industry Career Guide: Mining, Roberto Raymundo

Angelo King Institute for Economic and Business Studies (AKI)

The mining industry in the Philippines plays a very significant role in the pursuit of industrial development because of the sector’s ability to provide mineral resources that serve as raw materials for manufacturing, construction, the utilities as well as the transportation and communications sector. It is also a major contributor of foreign currency through the exports of mineral ore and other processed mineral products and provides employment to communities in far flung areas where the only source of economic activity is mining operations. The extraction of copper, gold, silver, nickel, coal, gas, oil, stone and gravel as well as finding …

Gravity And Magnetic Investigations Into Possible Economic Mineral Deposits Within The Northwest St. Francois Terrane, Southeastern Missouri, Brandon Todd Ives

Graduate Theses/Dissertations

The exposed Precambrian St. Francois Mountains in southeast Missouri are a well-studied terrane of rhyolites, granites, and basaltic dikes, but much of the buried basement lithology west of the exposed region is still poorly delineated. The western St. Francois is host to large hydrothermal Pb-Zn and Fe-oxide ore deposits, some of which were located with previous geophysical investigations. The economic ore deposits specifically in the Pea Ridge Mine in Washington County contain known economic minerals and rare earth element deposits. In order to further investigate the Precambrian basement lithologies and the possible locations of additional economic ore deposits, a gravity …

A Novel Powder Factor Based Bench Blast Design Method For Large Surface Coal Mines, Andrew Clifford Blair

Doctoral Dissertations

"Large surface coal mines in Wyoming's Powder River Basin ship millions of tons of coal per annum, moving millions of cubic yards of overburden to mine the coal. Much of this volume is blasted in the form of benches, a common mining technique. Increases in production and scale of equipment in the past thirty-five years have created a paradigm shift for drill and blast personnel at these large surface mines, and the explosives industry has yet to create a blast design method specifically tailored for large surface coal mine bench blasting.

This research examines the typical scale of bench blasting …

Numerical Study On Scaling Effects And Decoupled Network-Based Simulation Of Gaseous Explosion, Liang Wang

Doctoral Dissertations

"This research seeks to improve the prediction efficiency of gaseous explosions realized by numerical simulations in a full-scale underground network using a decoupled method. To provide quick predictions of overpressure distribution of methane explosions in underground airway networks, a two-section theory is employed. The explosion space is divided into a driver section and a blast-wave section. Governing equations including conservation of mass, momentum, and energy, together with chemical reaction and turbulence models are solved for the driver and the blast-wave sections using computational fluid dynamics (CFD) solver ANSYS Fluent (3D-based) and Flowmaster (1D-based) respectively. The three dimensional (3D) and one …

Describing Local Community Acceptance With Discrete Choice Theory For Enhanced Community Engagement, Sisi Que

Doctoral Dissertations

This research sought to facilitate improved community (stakeholder) analysis by providing further insight on the determinants of local community acceptance using discrete choice theory. Specifically, the goals were to: (1) Identify, classify, and verify the important project characteristics and key demographic factors which affect local community acceptance of a mining project; (2) Account for the large number of relevant factors inherent in discrete choice experiments for mining community acceptance evaluation; and (3) Examine discrete choice models to select the most appropriate model for mining community consultation. The research will test the hypotheses that various discrete choice models can describe the …

Analysis Of Effects Of Surface Roughness And Local Surface Imperfections On Measured Pressure, Laurin Ashley Bookout

Doctoral Dissertations

"When tests using pressure to characterize the performance or effects of an explosive are conducted in laboratory or other small scale, highly controlled settings, it is expected that any gages will be ideally mounted and there will not be any surface imperfections or roughness near the gage location. However, when explosive tests are scaled up, the test beds typically do not have perfect surfaces. Instead there may be rough surfaces with various types of geometry or situations where it is extremely difficult to get the gage flush mounted with a flat surface. In a time where tests with multiple replications …

Improving Processing By Adaption To Conditional Geostatistical Simulation Of Block Compositions, R. Tolosana-Delgado, Ute A. Mueller, K. G. Van Den Boogaart, C. Ward, J. Gutzmer

Research outputs 2014 to 2021

Exploitation of an ore deposit can be optimized by adapting the beneficiation processes to the properties of individual ore blocks. This can involve switching in and out certain treatment steps, or setting their controlling parameters. Optimizing this set of decisions requires the full conditional distribution of all relevant physical parameters and chemical attributes of the feed, including concentration of value elements and abundance of penalty elements. As a first step towards adaptive processing, the mapping of adaptive decisions is explored based on the composition, in value and penalty elements, of the selective mining units. Conditional distributions at block support are …

Ore Classification And Breccia Formation In The 144 Zone Gold Deposit: A Chemical Replacement Model, Bare Mountain Range, Nevada, William Thomas Fischer

UNLV Theses, Dissertations, Professional Papers, and Capstones

The 144 Zone is an oxidized, breccia-hosted, disseminated gold deposit that formed along the contact between Early Cambrian Carrara Formation limestone and overlying Bonanza King Formation dolomite within the Bare Mountain range in southern Nevada. Gold mineralization occurs within a breccia body that contains a variety of breccia types. Research goals of this project included classifying clay, oxide and other minerals as well as breccia types to identify the habits of gold mineralization and the minerals associated with gold. Research was also aimed at determining the paragenesis of Au mineralization and brecciation in the 144 Zone. Underground mapping provided spatial …

A Review Of Combined Advanced Oxidation Technologies For The Removal Of Organic Pollutants From Water, Jimoh O. Tijani, Ojo O. Fatoba, Godfrey Madzivire, Leslie F. Petrik

Mining Engineering Faculty Research & Creative Works

Water pollution through natural and anthropogenic activities has become a global problem causing short-and long-term impact on human and ecosystems. Substantial quantity of individual or mixtures of organic pollutants enter the surface water via point and nonpoint sources and thus affect the quality of freshwater. These pollutants are known to be toxic and difficult to remove by mere biological treatment. To date, most research on the removal of organic pollutants from wastewater were based on the exploitation of individual treatment process. This single-treatment technology has inherent challenges and shortcomings with respect to efficiency and economics. Thus, application of two advanced …

The Figure Of Bitu-Man, Paul Royster

University of Nebraska-Lincoln Libraries: Faculty Publications

The ominously imposing figure in the above illustration is “the Syncrude bird deterrent device, locally known as ‘Bitu-man’.” He stands (or stood—the original image was from the late 1970s) in the tailings pond of the Syncrude Canada Ltd. oil sands mining operation along the Athabasca River near Fort McMurray in northeastern Alberta. That operation surface mines (i.e., strip mines) bitumen-impregnated sand, processes it with hot water and steam, and discharges the liquid effluent or “tailings” into a pond covering roughly 3000 hectares (11 square miles). (Google Map coordinates: 56.9°N, -111.3° W). Residue bitumen collects on the surface and poses a …

Mapping Licit And Illicit Mining Activity In The Madre De Dios Region Of Peru, Arthur Elmes, Josué Gabriel Yarlequé Ipanaqué, John Rogan, Nicholas Cuba, Anthony J. Bebbington

Geography

Since the early 2000s, the Madre de Dios Region of southern Peru has experienced rapid expansion of both licit and illicit mining activities, in the form of artisanal and small-scale mining (ASM). ASM typically takes place in remote, inaccessible locations and is therefore difficult to monitor in situ. This paper explores the utility of Landsat-5 imagery via decision tree classification to determine ASM locations in Madre de Dios. Spectral mixture analysis was used to unmix Landsat imagery, using WorldView and QuickBird l imagery to aid spectral endmember selection and validate AMS maps. The ASM maps had an overall area-weighted accuracy …

Keeping Civilization From Collapsing, Thomas W. Camm

Mining Engineering

No abstract provided.

Fluid Properties In The Formation Of High-Grade Iron Ore In Northern Minnesota, Elizabeth Drommerhausen

Journal of Undergraduate Research at Minnesota State University, Mankato

The Mesabi Iron Range in Northern Minnesota has been a major producer of iron ore for over 100 years. Production has been from the 1.85 – billion-year –old Biwabik Iron Formation, an iron-rich sedimentary rock that is tilted gently to the south. Most of the known high-grade ore lies near the surface and has been already mined. Determining whether more high-grade ore may lie at depth could have significant economic impact on the mining industry in northern Minnesota. To evaluate the likelihood of finding more high-grade iron ore deeper underground, it is important to determine the source of the fluids …

Study On Deterioration Mechanism And Prevention And Curing Techniques Of An Rc Bunker, Henglin Lv, Haijian Xie, Shuchun Zhou, Sun Lei

International Conference on Durability of Concrete Structures

In the coal mining industrial environment, the materials of RC bunkers suffer from serious aging problems. The cracking and deterioration of concrete and the corrosion of steel reinforcement lead to a degeneration of structural performance and a decline of structural reliability. In this paper, based on on-site detection and coal mining ground industrial environment, the deterioration characteristics of RC bunkers were tested. The investigation involved the apparent characteristics, carbonized depth, compression strength of concrete, reinforcement distribution and cover thickness, corrosion rate and mechanical properties of reinforcement, decline degree of bunkers, and so on. Then a design review check was done. …

Separation Of Ash And Sulfur Dioxide During The 2011 Grímsvötn Eruption, E. D. Moxnes, N. I. Kristiansen, A. Stohl, L. Clarisse, A. J. Durant, K. Weber, A. Vogel

Michigan Tech Publications, Part 1

Modeling the transport of volcanic ash and gases released during volcanic eruptions is crucially dependent on knowledge of the source term of the eruption, that is, the source strength as a function of altitude and time. For the first time, an inversion method is used to estimate the source terms of both volcanic sulfur dioxide (SO2) and ash. It was applied to the explosive volcanic eruption of Grímsvötn, Iceland, in May 2011. The method uses input from the particle dispersion model, FLEXPART (flexible particle dispersion model), a priori source estimates, and satellite observations of SO2 or ash total columns from …

Absorption And Fluorescence Properties Of Chromophoric Dissolved Organic Matter Of The Eastern Bering Sea In The Summer With Special Reference To The Influence Of A Cold Pool, E. J. D'Sa, J. I. Goes, H. Gomes, C. Mouw

Michigan Tech Publications, Part 1

The absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) are reported for the inner shelf, slope waters and outer shelf regions of the eastern Bering Sea during the summer of 2008, when a warm, thermally stratified surface mixed layer lay over a cold pool ( < 2 °C) that occupied the entire middle shelf. CDOM absorption at 355 nm (ag355) and its spectral slope (S) in conjunction with excitation-emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC) revealed large variability in the characteristics of CDOM in different regions of the Bering Sea. PARAFAC analysis aided in the identification of three humic-like (components one, two and five) and two protein-like (a tyrosine-like component three, and a tryptophan-like component four) components. In the extensive shelf region, average absorption coefficients at 355 nm (ag355, mg-1) and DOC concentrations (μM) were highest in the inner shelf (0.342 ± 0.11 mg-1, 92.67 ± 14.60 μM) and lower in the middle (0.226 ± 0.05 mg-1, 78.38 ± 10.64 μM) and outer (0.185 ± 0.05 mg-1, 79.24 ± 18.01 μM) shelves, respectively. DOC concentrations, however were not significantly different, suggesting CDOM sources and sinks to be uncoupled from DOC. Mean spectral slopes S were elevated in the middle shelf (24.38 ± 2.25 μmg-1) especially in the surface waters (26.87 ± 2.39 μmg-1) indicating high rates of photodegradation in the highly stratified surface mixed layer, which intensified northwards in the northern middle shelf likely contributing to greater light penetration and to phytoplankton blooms at deeper depths. The fluorescent humic-like components one, two, and five were most elevated in the inner shelf most likely from riverine inputs. Along the productive "green belt" in the outer shelf/slope region, absorption and fluorescence properties indicated the presence of fresh and degraded autochthonous DOM. Near the Unimak Pass region of the Aleutian Islands, low DOC and ag355 (mean 66.99 ± 7.94 μM; 0.182 ± 0.05 mg-1) and a high S (mean 25.95 ± 1.58 μmg-1) suggested substantial photobleaching of the Alaska Coastal Water, but high intensities of humic-like and protein-like fluorescence suggested sources of fluorescent DOM from coastal runoff and glacier meltwaters during the summer. The spectral slope S vs. ag355 relationship revealed terrestrial and oceanic end members along with intermediate water masses that were modeled using nonlinear regression equations that could allow water mass differentiation based on CDOM optical properties. Spectral slope S was negatively correlated (r2 = 0.79) with apparent oxygen utilization (AOU) for waters extending from the middle shelf into the deep Bering Sea indicating increasing microbial alteration of CDOM with depth. Although our data show that the CDOM photochemical environment of the Bering Sea is complex, our current information on its optical properties will aid in better understanding of the biogeochemical role of CDOM in carbon budgets in relation to the annual sea ice and phytoplankton dynamics, and to improved algorithms of ocean color remote sensing for this region.

Depolarization Mechanisms Of Pbzr0.52ti0.48o3 And Pbzr0.95ti0.05o3 Poled Ferroelectrics Under High Strain Rate Loading, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Evgueni F. Talantsev, Hwan R. Jo

Mining Engineering Faculty Research & Creative Works

Stress-induced and thermal-induced depolarization studies along with X-ray diffraction were performed on lead zirconate titanate ferroelectrics of different compositions, PbZr_0.52Ti_0.48O₃ (PZT 52/48) and PbZr_0.95Ti_0.05O₃ (PZT 95/5). Specimens were shocked loaded perpendicular to the polarization vector. It was found that the polarity of the stress-induced charge released by PZT 52/48 and 95/5 was opposite to the polarity of the charge generated due to the piezoelectric effect. PZT 52/48 was only partially (45%) depolarized under 1.5±0.1 GPa mechanical compression, as opposed to PZT 95/5 which was fully depolarized. The experimental results indicate …

Seasonal Variability And Long-Term Evolution Of Tropospheric Composition In The Tropics And Southern Hemisphere, K. M. Wai, S. Wu, A. Kumar, H. Liao

Michigan Tech Publications, Part 1

Impacts on tropospheric composition in the tropics and the Southern Hemisphere from biomass burning and other emission sources are studied using a global chemical transport model, surface measurements and satellite retrievals. Seasonal variations in observed CO at remote island sites are examined. Easter Island (eastern Pacific Ocean) is impacted indirectly by the hemispheric zonal transport of CO due to the burning in southern Africa/South America, via the westerlies. An increasing trend in CO by 0.33 ppb yr-1 in the past decade at Ascension Island is attributed to the combined effects of South American/southern Africa burnings and the increases in CH4 …

The Dark Side Of Leadership: Dealing With A Narcissistic Boss, Thomas W. Camm

Mining Engineering

Some of the defining characteristics of narcissists include a grandiose sense of self-importance, preoccupation with success and power, a sense of infallibility, and a supreme confidence in their ability and intelligence. Ironically, many of these characteristics are rewarded in business organizations, which may explain why there seems to be so many narcissists in management positions. Assuming we will be dealing with narcissists throughout our career, it makes sense for us to understand what makes them tick, and more importantly what we can do to work with them in a constructive manner.

An Analysis Of Burn Cut Pull Optimization Through Varying Relief Hole Depths, Michael Robert Allen

Masters Theses

"In underground blasting, the pull of the initial cut is the limiting factor for the success of the rest of the round. By improving the pull of the first cut, a critical step is made towards improving the entire round. This project attempted to optimize a burn cut's effective pull by varying the depths of the relief holes in the burn, and then analyzing the results. In testing, relief holes were drilled to depths both shorter and longer than that of the cut's charged holes. The overall objective was to consistently achieve greater pull than in a standard burn, using …

Innovative Rts Technology For Dry Beneficiation Of Phosphate, Ahmed Sobhy, Daniel Tao

Mining Engineering Faculty Research & Creative Works

The Crago double flotation process is widely used for upgrading raw phosphate in Florida. However, it is a water-based physicochemical process and consumes a huge amount of water and chemicals and is not efficient to remove dolomite from phosphate. In addition, the final phosphate flotation concentrate often has a grade of 30-31% P2O5, which is below the BPL content of 75% (or 34.3% P2O5) required for making the animal feed grade phosphate. This study is performed to evaluate the potential and feasibility of the innovative rotary triboelectrostatic separator (RTS) as a dry phosphate beneficiation process. The RTS technology is characterized …