Mining Engineering Commons^™

Calling For Justice In The Goldfields Of Tanzania, Madoshi H. Makene, Jody Emel, James T. Murphy

Geography

Tanzania is the third largest gold exporter in Africa, thanks in part to the liberalization of the mining sector which started in the early 1990s. Neoliberal mining reforms promised a win-win situation in which government, investors and local host communities would benefit through export earnings, profits, local employment, andcorporate social responsibility initiatives (e.g., the building of schools and clinics). While the rising price of gold and foreign investments in mining activities have delivered on some of these promises, many residents in mining regions have not benefited socioeconomically. Worse still, their communities have unjustly borne the brunt of the environmental, social, …

The Effects Of Water On Sympathetic Detonation And Dead Pressing Of Dynamite And Emulsions, Adam Michael Doerfler

Masters Theses

Dynamite and emulsions are very effective explosives in blasting; however they do have some shortcomings. Dynamite is prone to sympathetic detonation whereas emulsions are prone to dead pressing. While this does not happen all the time, the conditions in which the explosives are used do have an effect on whether or not they will sympathetically detonate or dead press.

Numerous researchers have investigated sympathetic detonation for a relationship between the distance between charges, hole separation distance, and size of explosive. This research aimed to look at how hole separation distance was affected when water was introduced into the boreholes for …

Effects Of Coal Comminution In Relation To Waterjet And Selected Feed Properties, Yaqing Li

Masters Theses

"The necessity to develop a viable alternative to oil means that the development of coal-water fuels (CWF) has become increasingly important. However, the existing methods of comminution to prepare ultrafine particles for CWF are very inefficient. Consequently, a number of novel methods of comminution have been investigated in order to increase the efficiency of the process.

In this research, a new method of comminution using a high-pressure waterjet has been tested to produce ultrafine particle sizes necessary for efficient CWF process. To establish the fundamental performance of the waterjet mill, the influence of the operational pressure, standoff distance, feed size, …

The Simulation Of Material Types In A Western Australian Iron Deposit, Jacqueline Ferreira

Theses: Doctorates and Masters

Geostatistical methods are currently used by mining companies to determine a resource model of the tonnage and head grade that may be obtained from a potential orebody, making it one of the first and most vital operational stages in any mining project. Currently long term mine planning is based on the estimated head grades model, which provides vital information on the quality of the ore. The risks associated with mining a particular ore may be reduced if geometallurgical information, such as material types, is incorporated into the operational flow model. Material type proportions are obtained from evaluated reverse circulation (RC) …

Geostatistical Methods For Estimating Iron, Silica And Alumina Grades Within The Hardcap Of The Section Seven Iron Deposit, Tom Price, Philip John Savory

Theses: Doctorates and Masters

Many iron ore deposits have a weathered zone (Hardcap) near the surface which is highly variable in grades. Estimating the amount of ore grade material (HG) in this zone is difficult as a result of this variability. The Section Seven Deposit at Tom Price is largely mined out and has production data available in the form of grade blocks that were marked out during mining as HG and non- HG. Hardcap domains and a block model representing them were created and estimates were made from original exploration data using Ordinary Kriging, Global Change of Support, Indicator Kriging and Median Indicator …

The Psychological Wellbeing Of Women Operating Mining Machinery In A Fly-In Fly-Out Capacity, Anne Bailey-Kruger

Theses: Doctorates and Masters

The present study aimed to address the gap in the current mining research by investigating women’s experiences of working in the mining industry in a “bluecollar” work role and the impact of fly-in fly-out (FIFO) mining on their wellbeing. An Interpretative Phenomenological Approach (IPA) was used as a framework to explore the experiences of 19 female machine operators through in-depth interviewing at one mineral mine site in Queensland, Australia. IPA analysis revealed three themes as identified by the participants. The first theme described how workplace barriers to job progression were salient issues for the women, particularly in respect to discrimination …

Finite Element Analysis Of Blade-Formation Interactions In Excavation, Osei Brown

Masters Theses

"The efficiency and costs of mining operations greatly depend on the efficient design and use of excavators. The performance of these capital-intensive excavators requires thorough understanding of the physical and design factors that affect the formation-cutting tool interaction process. The current body of knowledge, based on experimental and analytical methods, provides limited understanding of these factors, which limits the accurate design and performance of excavators. The soil constitutive equations used in most of the available finite element (FE) models also fail to adequately capture the elastic and plastic behaviors of soil formations. This research initiative uses FE techniques to model …

Development Of Strategies To Minimize The Release Of Trace Elements From Coal Waste Sources, Mohammad Rezaee

Theses and Dissertations--Mining Engineering

To assess strategies aimed at minimizing the release of trace elements and the impact of disposal of coal waste materials on the environment, two long-term leaching experiments of up to five months duration were performed using waste materials from two plants cleaning high and low sulfur bituminous coal. The tests evaluated the mobility of major trace elements under different disposal scenarios: (i) a static leaching test designed to simulate the quiescent conditions encountered by coal waste material stored under water in a stable impoundment, and (ii) a dynamic test to simulate waste materials exposed to the atmosphere, either in variable …

Underground Mine Fire Simulation Using Multiscale Modeling Approach, Xichen Zhang

Doctoral Dissertations

"Underground mine fires have always been a major concern. Past events show that fire poses a severe safety hazard to mine workers, and causes tremendous economic loss to the mine and surrounding communities. A good understanding of the interaction between a mine fire and the mine ventilation network is crucial for effective fire emergency planning and hazard control. Unfortunately our understanding of a fire is still limited due to the complex nature of mine fires and a lack of adequate resource for studying them.

A new multiscale modeling approach coupling conventional 1D and 3D techniques has shown to be a …

Shock-Tunnel Waveform Analysis, Dave Mclane, John Rathbun

Kaleidoscope

No abstract provided.

Ethane, Ethyne And Carbon Monoxide Concentrations In The Upper Troposphere And Lower Stratosphere From Ace And Geos-Chem: A Comparison Study, G. González Abad, N. D.C. Allen, P. F. Bernath, C. D. Boone, S. D. Mcleod, G. L. Manney, G. C. Toon, C. Carouge, Y. Wang, Shiliang Wu, X

Michigan Tech Publications

Near global upper tropospheric concentrations of carbon monoxide (CO), ethane (C2H6) and ethyne (C2H2) from ACE (Atmospheric Chemistry Experiment) Fourier transform spectrometer on board the Canadian satellite SCISAT-1 are presented and compared with the output from the Chemical Transport Model (CTM) GEOS-Chem. The retrievals of ethane and ethyne from ACE have been improved for this paper by using new sets of microwindows compared with those for previous versions of ACE data. With the improved ethyne retrieval we have been able to produce a near global upper tropospheric distribution of C2H2 from space. Carbon monoxide, ethane and ethyne concentrations retrieved using …

Geotechnique, Physico-Chemical Behaviour And A New Erosion Model For Mine Tailings Under Environmental Loading, Rozalina S. Dimitrova

Electronic Thesis and Dissertation Repository

Comprehensive geotechnical characterisation of mine tailings is required for the design, construction and safe operation of mine waste management facilities against the large number of potential failure risks. It is important that the characterization is carried out under the stress range and drainage conditions relevant to those encountered in the field.

The present research utilized mine tailings samples from a copper/nickel base-metal mine. Kaolinite and bentonite clays were added to the mine tailings in order to study the effect of clay percentage and clay mineralogy on the behaviour of saturated tailings/clay systems with varying composition. Slurries with moderate or high …

Opportunistic Validation Of Sulfur Dioxide In The Sarychev Peak Volcanic Eruption Cloud, S. Carn, T. M. Lopez

Michigan Tech Publications

We report attempted validation of Ozone Monitoring Instrument (OMI) sulfur dioxide (SO 2) retrievals in the stratospheric volcanic cloud from Sarychev Peak (Kurile Islands) in June 2009, through opportunistic deployment of a ground-based ultraviolet (UV) spectrometer (FLYSPEC) as the volcanic cloud drifted over central Alaska. The volcanic cloud altitude (∼12-14 km) was constrained using coincident CALIPSO lidar observations. By invoking some assumptions about the spatial distribution of SO 2, we derive averages of FLYSPEC vertical SO 2 columns for comparison with OMI SO 2 measurements. Despite limited data, we find minimum OMI-FLYSPEC differences within measurement uncertainties, which support the validity …

Note: Miniature 120-Kv Autonomous Generator Based On Transverse Shock-Wave Depolarization Of Pb(Zr0.52ti0.48)O₃ Ferroelectrics, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

The design of autonomous ultrahigh-voltage generators with no moving metallic parts based on transverse explosive shock wave depolarization of Pb(Zr_0.52Ti_0.48)O₃ (PZT 5248) poled ferroelectrics was explored and studied. It follows from experimental results that the output voltage produced by the shock-wave ferroelectric generators (FEGs) is directly proportional to the number of PZT 5248 elements connected in series. It was demonstrated that miniature FEGs (volume less than 180 cm³) were capable of reliably producing output voltage pulses with amplitudes exceeding 120 kV which is the record reported in open literature.

Sulphur Dioxide As A Volcanic Ash Proxy During The April-May 2010 Eruption Of Eyjafjallajökull Volcano, Iceland, H. E. Thomas, A. J. Prata

Michigan Tech Publications

The volcanic ash cloud from the eruption of Eyjafjallajökull volcano in April and May 2010 resulted in unprecedented disruption to air traffic in Western Europe causing significant financial losses and highlighting the importance of efficient volcanic cloud monitoring. The feasibility of using SO2 as a tracer for the ash released during the eruption is investigated here through comparison of ash retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) with SO2 measurements from a number of infrared and ultraviolet satellite-based sensors. Results demonstrate that the eruption can be divided into an initial ash-rich phase, a lower intensity middle phase …

Electric Breakdown Of Longitudinally Shocked Pb(Zr₀.₅₂Ti₀.₄₈)O₃ Ceramics, S. I. Shkuratov, E. F. Talantsev, Jason Baird

Mining Engineering Faculty Research & Creative Works

Electric breakdown of longitudinally-shock-compressed Pb(Zr₀.₅₂Ti₀.₄₈)O₃ (PZT 52/48) ferroelectric ceramics was experimentally investigated. It was found that a dependence of breakdown field strength, E_g, of shocked ferroelectrics on the thickness of the element, d, ranging from 0.65 to 6.5 mm is described by the E_g (d) = γ  · d^-w law that describes the breakdown of dielectrics at ambient conditions. It follows from the experimental results that the tunnel effect is a dominant mechanism of injection of prime electrons in the shocked ferroelectric elements. It was demonstrated that electric breakdown causes significant energy losses in miniature autonomous …

Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, J. S. Fu, S. Wu, L. J. Mickley

Michigan Tech Publications

Simulations of present and future average regional ozone and PM 2.5 concentrations over the United States were performed to investigate the potential impacts of global climate change and emissions on regional air quality using CMAQ. Various emissions and climate conditions with different biogenic emissions and domain resolutions were implemented to study the sensitivity of future air quality trends from the impacts of changing biogenic emissions. A comparison of GEOS-Chem and CMAQ was performed to investigate the effect of downscaling on the prediction of future air quality trends. For ozone, the impacts of global climate change are relatively smaller when compared …

Determination Of Time-And Height-Resolved Volcanic Ash Emissions And Their Use For Quantitative Ash Dispersion Modeling: The 2010 Eyjafjallajökull Eruption, A. Stohl, A. J. Prata, S. Eckhardt, L. Clarisse, A. Durant, S. Henne, N. I. Kristiansen, A. Minikin, U. Schumann, P. Seibert, K. Stebel, H. E. Thomas, T. Thorsteinsson, K. Tørseth, B. Weinzierl

Michigan Tech Publications

The Aprilg-May, 2010 volcanic eruptions of Eyjafjallajökull, Iceland caused significant economic and social disruption in Europe whilst state of the art measurements and ash dispersion forecasts were heavily criticized by the aviation industry. Here we demonstrate for the first time that large improvements can be made in quantitative predictions of the fate of volcanic ash emissions, by using an inversion scheme that couples a priori source information and the output of a Lagrangian dispersion model with satellite data to estimate the volcanic ash source strength as a function of altitude and time. From the inversion, we obtain a total fine …

The Depolarization Of Pb(Zr0.52ti0.48)O₃ Ferroelectrics By Cylindrical Radially Expanding Shock Waves And Its Utilization For Miniature Pulsed Power, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

The effects of depolarization of Pb(Zr_0.52Ti_0.48)O₃ (PZT 52/48) poled ferroelectrics by cylindrical radially expanding shock waves propagated along and across the polarization vector P₀ were experimentally detected. Miniature (total volume 100 cm³) autonomous generators based on these effects were capable of producing output voltage pulses with amplitudes up to 25 kV and output energies exceeding 1 J.

Fuzzy Controlled Hydraulic Excavator With Model Parameter Uncertainty, Ganesh Kothapalli, Mohammed Hassan

Research outputs 2011

The hydraulic actuated excavator, being a non-linear mobile machine, encounters many uncertainties. There are uncertainties in the hydraulic system in addition to the uncertain nature of the load. The simulation results obtained in this study show that there is a need for intelligent control of such machines and in particular interval type-2 fuzzy controller is most suitable for minimizing the position error of a typical excavator’s bucket under load variations. We consider the model parameter uncertainties such as hydraulic fluid leakage and friction. These are uncertainties which also depend up on the temperature and alter bulk modulus and viscosity of …