Mining Engineering Commons^™

Fundamental Improvement In The Tribocharging Separation Process For Upgrading Coal, Jinxiang Chen

Theses and Dissertations--Mining Engineering

Triboelectrostatic separation is a physical separation technique that is based on surface electronic property differences among minerals to achieve a separation. Minerals have different surface conductivities and electron affinities. They are charged differently in quantity and/or polarity after a tribocharging process. Particles with different surface charges move discretely under external electric field produce a separation. Electrostatic separation is a dry mineral processing method that does not require any water or chemical reagents. It can greatly simplify the processing circuit and reduce operating cost. Additionally, problems caused by water in conventional wet mineral processing such as water freezing, dewatering, water pollution …

Designing Efficient Petroleum Fiscal System For Mozambique, Nelson Victor

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, tax regime is designed to attract investment and provide the contractor with fair return on investment, at the same time, provide the host government with adequate resources for rent, thereby resulting in win-win situation. This study analyses the existing petroleum fiscal regime in the Republic of Mozambique and proposes a more efficient and flexible regime. The analysis shows that the government take currently remains at around 39% while the contactors' net present value (NPV) increases as field sizes and oil prices increase. The current system is considered a regressive system which is inefficient in distributing wealth from oil profit. …

Real-Time Diesel Particulate Matter Monitoring In Underground Mine Atmospheres, Association With The Standard Method And Related Challenges, Muhammad Usman Khan

Doctoral Dissertations

"Diesel-powered equipment is a significant component of underground mining operations. Miners' exposure to diesel exhaust is harmful. The standard Diesel Particulate Matter (DPM) monitoring method (NIOSH 5040 method) has limitations that preclude rapid DPM estimation and detailed understanding of DPM variations over time. However, real-time DPM monitors do not inherit these limitations. Biodiesel is often used as a substitute for regular petroleum-diesel because of its ability to emit less DPM. However, accuracy of available real-time DPM monitors has not been determined in mines using 70% to 99% (high-percent) biodiesel. The present research addresses this need by rigorous testing of a …

Mining Asteroids For Volatile Resources: An Experimental Demonstration Of Extraction And Recovery, Egboche Christopher Unobe

Masters Theses

"Gaseous compounds trapped within carbonaceous asteroids may prove to be important targets for prospective space miners in the near-term. Volatile release is from hydrated, hydroxylated and carbonated phases present, making such bodies attractive as feedstock for the production of H₂O, CO₂ and simple organic compounds. A source of these species in orbit provides an opportunity to locally produce space-craft propellant and other life-support gases through the application of In-situ Resource Utilization (ISRU).

For this study, an experimental vacuum system was modified and used to test the technical validity of radiatively heating asteroid simulants to extract contained gaseous …

Detection Of Mine Roof Failure Using Inexpensive Lidar Technology, Ali Abdullah M. Alzahrani

Masters Theses

"Slope, Roof, and mine wall stability problems are some of the main reasons for deaths at U.S. surface or underground mining. The safety instruments were not enough to prevent that failure or even predict it before it occurs. However, the cost of such a tool that can be helpful in detecting roof failures is very high and not reachable in most instances.

The present study investigates the feasibility of using the M16 Leddar Evaluation Kit to detect the roof failure in mines. The M16 Leddar Evaluation kit cost is between 300$-800$, so it is the reachable price if it provides …

Recovery Of Phosphate Minerals From Plant Tailings Using Direct Froth Flotation Process, Ashraf Alsafasfeh

Masters Theses

"The wastes produced from phosphate industry presents many challenges due to the economic and environmental impacts of their disposal. In the meantime, scarcity of high-grade phosphate ores persuades researchers to find novel methods of upgrading these wastes (secondary sources) and recycling them in the production plant circuit. The goal of this study is to investigate the potential to upgrade the phosphorus content in the tailing produced from a phosphorous production plant using direct froth flotation process. Characterization studies such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and mineral liberation analysis (MLA) were first conducted to identify the mineralogical and …

Controlling Properties Of Agglomerates For Chemical Processes, Joseph A. Halt

Dissertations, Master's Theses and Master's Reports

Iron ore pellets are hard spheres made from powdered ore and binders. Pellets are used to make iron, mainly in blast furnaces. Around the time that the pelletizing process was developed, starch was proposed as a binder because it’s viscous, adheres well to iron oxides, does not contaminate pellets and is relatively cheap. In practice, however, starch leads to weak pellets with rough surfaces – these increase the amount of dust generated within process equipment and during pellet shipping and handling. Thus, even though the usual binder (bentonite clay) contaminates pellets, pelletizers prefer it to starch or other organics.

This …

The Andacollo's Mining Community: Ethnographic Work-Based Approach To Corporate Social Responsibility Policies And Practices, Ubirata De Oliveira

Walden Dissertations and Doctoral Studies

This ethnographic study was designed to explore the phenomenon of corporate social responsibility (CSR) in the mining industry. The research addressed the impacts of a problematic, systemic, and ethnocentric (top-down) CSR approach driven by a transnational mining company, and proposed a novel cultural relativist (bottom-up) CSR approach looking at the social needs of the community. Solving the problem stemming from the ethnocentric approach is important for both the mining company and the community affected by the CSR program, as it will alter dynamics between actors and mitigate social conflicts. The purpose of this study was to investigate factors that improve …

Thermomechanical Fatigue Life Investigation Of An Ultra-Large Mining Dump Truck Tire, Wedam Nyaaba

Doctoral Dissertations

The cost benefits associated with the use of heavy mining machinery in the surface mining industry has led to a surge in the production of ultra-large radial tires with rim diameters in excess of 35 in. These tires experience fatigue failures in operation. The use of reinforcing fillers and processing aids in tire compounds results in the formation of microstructural inhomogeneity in the compounds and may serve as sources of crack initiation in the tire. Abrasive material cutting is another source of cracks in tires used in mining applications. It suffices, then, to assume that every material plane in the …

Characterization And Numerical Simulation Of The Microstructural And Micromechanical Viscoelastic Behavior Of Oil Sands Using The Discrete Element Method, Eric Kofi Gbadam

Doctoral Dissertations

"Oil sands are naturally geologic formations of predominantly quartz sand grains whose void spaces are filled with bitumen, water, and dissolved gases. The electric rope shovel is the primary equipment used for excavating the Athabasca oil sand formations. The equipment's static and dynamic loads are transferred to the formation during excavation and propel. These loads cause ground instability leading to sinkage or rutting, crawler wear, and fracture failures. These problems result in unplanned downtimes, production losses, and high maintenance costs. In order to address these problems, there is a need to develop valid models that capture the behavior and performance …

Lhd Vibrations Analysis And Numerical Modeling During Operations, Kgosietsile Kolobe

Doctoral Dissertations

"Load-haul-dump vehicles (LHDs) are extensively used as primary loaders in mining operations. LHDs have proven to be vigorous, extremely productive and reliable in mining applications. They have a wide range of tramming capacities that have enabled them to become an essential component in the hard rock mining industry.

Increased mining economic challenges and global competition means the mining industry has to maximize productivity by cutting down operating and capital costs. Also, improvements in safety standards have led to the demand for safer and efficient machines.

LHD operators are at a high risk of whole-body vibrations (WBVs) exposure leading to musculoskeletal …

The Influence Of Caprock On Blast Fragmentation Distribution, Matthew Kurtis Coy

Doctoral Dissertations

"This dissertation describes the development of a small-scale model of a caprock-laden quarry blast and discusses the results from that testing. The purpose of this testing was to provide insight into the reasons for poor caprock breakage during blasting.

Small-scale test blocks were poured using a weak mortar mix to represent a limestone formation at a small scale. A cold joint was created in the upper portion of the test specimens to represent the bedding plane that separates caprock and substrate layers in a caprock-laden limestone bench. The scale-model test blocks were blasted using detonating cord. The primary configuration for …

Fiber Bragg Grating Sensors For Mainstream Industrial Processes, Gary Allwood, Graham Wild, Steven Hinkley

Research outputs 2014 to 2021

This paper reviews fiber Bragg grating sensing technology with respect to its use in mainstream industrial process applications. A review of the various types of sensors that have been developed for industries such as power generation, water treatment and services, mining, and the oil and gas sector has been performed. A market overview is reported as well as a discussion of some of the factors limiting their penetration into these markets. Furthermore, the author’s make recommendations for future work that would potentially provide significant opportunity for the advancement of fiber Bragg grating sensor networks in these mainstream industries.

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 …

Pillar Design For St. Peter Sandstone Formation, Francis Anohomah Arthur

Doctoral Dissertations

"Silica sands produced primarily from St. Peter Sandstone are used for hydraulic fracturing in the petroleum industry, glassmaking, chemicals, ceramics, filtration and the foundry industry in the US. The recent high demand for silica sands for hydraulic fracturing has triggered increased production and commissioning of new silica sand mines to support natural gas production from shale and tight gas deposits in the US. Most mines use surface mining methods to extract St. Peter Sandstone. The room and pillar mining method has been successfully used for St. Peter Sandstone mining in a few US locations, however, no one has proposed a …

Coal Combustion Products Utilization For Soil Amendment, Tran Thi Anh Tuyet

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, coal has a crucial role in generating energy all over the world. As a result, the consumption of coal creates a huge amount of coal combustion products, including bottom ash and fly ash. The coal ash has the potential characteristics to become a resource material in agriculture such as its texture, water holding capacity, bulk density, pH etc., and contains almost all the essential plant nutrients. However, most of the coal ash created is dumped into the landfill, which is a contributing factor in the environmental degradation. This study wants to use coal ash in agriculture as a way …

Time Series Pattern Discovery Techniques For Well-To-Well Log Correlation, Chanchai Apiwatsakulchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Well log data is one of the most abundant data sources for subsurface characterization since almost all drilled wells are logged. Subsurface characterization requires correlated well log information. Processes to help perform well-to-well log correlation have been developed in this study based on the two approaches: pattern matching and pattern discovery. Pattern matching focuses on finding a known pattern of interest in uncorrelated wells. The use of Euclidean, Hamming, and Levenshtein distances in similarity measurement, Piecewise Aggregate Approximation (PAA), and Symbolic Aggregate approXimation (SAX) data representation helps create reduced-resolution while maintains the main characteristics of the signals. Multi-resolution analysis provides …

Quantitating Active Photosystem Ii Reaction Center Content From Fluorescence Induction Transients, Cole D. Murphy, Guangyan Ni, Gang Li, Audrey Barnett, Kui Xu, Jessica Grant-Burt, Justin D. Liefer, David J. Suggett, Douglas A. Campbell

Michigan Tech Publications, Part 1

Photosystem II (PSII) is a pigment-protein complex that photochemically extracts electrons from water, generating the reductant that supports biological productivity in all biomes. Estimating the content of active PSII reaction centers in a liquid sample is a key input for estimating aquatic photosynthesis rates, as well as for analyzing phytoplankton stress responses. Established procedures for PSII content quantification based on oxygen evolution are slow, imprecise and require dense cell suspensions, and are thus inapplicable to many laboratory or field studies. A new approach uses baseline chlorophyll fluorescence emission divided by the effective absorbance cross section for PSII photochemistry, with both …

Electromagnetic Signal Feedback Control For Proximity Detection Systems, Adam K. Smith

Dissertations, Master's Theses and Master's Reports

Coal is the most abundant fossil fuel in the United States and remains an essential source of energy. While more than half of coal production comes from surface mining, nearly twice as many workers are employed by underground operations.

One of the key pieces of equipment used in underground coal mining is the continuous mining machine. These large and powerful machines are operated in confined spaces by remote control. Since 1984, 40 mine workers in the U. S. have been killed when struck or pinned by a continuous mining machine. It is estimated that a majority of these accidents could …

A Novel Method For Sensorless Speed Detection Of Brushed Dc Motors, Ernesto Vazquez-Sanchez, Joseph Sottile, Jaime Gomez-Gil

Mining Engineering Faculty Publications

Many motor applications require accurate speed measurement. For brushed dc motors, speed can be measured with conventional observers or sensorless observers. Sensorless observers have the advantage of not requiring any external devices to be attached to the motor. Instead, voltage and/or current are measured and used to estimate the speed. The sensorless observers are usually divided into two groups: those based on the dynamic model, and those based on the ripple component. This paper proposes a method that measures the current of brushed dc motors and analyses the position of its spectral components. From these spectral components, the method estimates …