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Articles 1 - 30 of 31
Full-Text Articles in Engineering
Wall Control Blasting At The Orphan Boy Mine – Butte, Montana, Jewel Sakyi
Wall Control Blasting At The Orphan Boy Mine – Butte, Montana, Jewel Sakyi
Graduate Theses & Non-Theses
Blasting is often conducted to produce desirable fragment sizes to minimize production cost and energy consumption in downstream processes, including loading, hauling, and crushing. However, the venting of explosive energy in the rock formation sometimes causes unwanted damage beyond the desired perimeter of the blast area. Control blasting has mainly been used in surface mining operations to minimalize blast damage. To explore the applicability of control blasting in underground mining operations, protect the safety of students, faculty, and staff, prevent overbreak, and to ensure the stability of openings and workings, four experimental control blasts, comprising of three smooth blasts and …
Developing Trees Tolerant To Degraded Mine Soils, Francis Inkoom
Developing Trees Tolerant To Degraded Mine Soils, Francis Inkoom
Graduate Theses & Non-Theses
The project discussed in this thesis is part of a larger project developing trees that can tolerate and withstand heavy metals and acidic soils from historic mining operations in Butte Montana as a solution to re-establishing long-term tree growth on those sites. The project involved growing tree seedlings native to Butte, Montana and planting them on degraded mine soils, tailings, and processing wastes (mine waste) located within the Butte Priority Soil Operable Unit (BPSOU). The seedlings were grown for 34 weeks in a greenhouse located on Montana Tech’s campus before being transplanted to a contaminated site (the Clark Mill site) …
Predictive Modeling Of Dc Arc Flash In 125 Volt System, Austin Cody Gaunce
Predictive Modeling Of Dc Arc Flash In 125 Volt System, Austin Cody Gaunce
Theses and Dissertations--Mining Engineering
Arc flash is one of the two primary hazards encountered by workers near electrical equipment. Most applications where arc flash may be encountered are alternating current (AC) electrical systems. However, direct current (DC) electrical systems are becoming increasingly prevalent with industries implementing more renewable energy sources and energy storage devices. Little research has been performed with respect to arc flash hazards posed by DC electrical systems, particularly energy storage devices. Furthermore, current standards for performing arc flash calculations do not provide sufficient guidance when working in DC applications. IEEE 1584-2002 does not provide recommendations for DC electrical systems. NFPA 70E …
The Redesigned Vortecone: A Maintenance-Free Wet Scrubber Device, Allison Taylor
The Redesigned Vortecone: A Maintenance-Free Wet Scrubber Device, Allison Taylor
Theses and Dissertations--Mining Engineering
Dust creates health and safety issues in mining and there are several different ways to reduce the amount of respirable dust created. Dust particles also affect the operation and efficiency of mining equipment. One device currently used to reduce dust in a coal mine is a flooded-bed dust scrubber. These type of scrubbers are found on continuous miners and are designed to capture dust particles close to the cutting head. However, the fibrous screens on the flooded-bed dust scrubber clog easily reducing both production and the quality and quantity of air miners are exposed too. The flooded-bed dust scrubber was …
Feed Control: Composite Recycle, Rosy Perez
Feed Control: Composite Recycle, Rosy Perez
All Undergraduate Projects
The Boeing Company gave Central Washington University an opportunity for students to research and come up with an idea to reduce costs and landfill waste caused by the trimmings from the 777x composite wing pieces. The engineering and manufacturing for this project is about transporting composite material through to the delamination and chipper process. The delamination process uses a ram to press two claw shaped devices together that bends and deforms the material in opposite directions. The chipper process uses counter rotating saw blades spaced 1/8” apart to produce small shredded material. It is important for this newly designed feed …
Leaching Characteristics Of Rare Earth Elements From Bituminous Coal-Based Sources, Xinbo Yang
Leaching Characteristics Of Rare Earth Elements From Bituminous Coal-Based Sources, Xinbo Yang
Theses and Dissertations--Mining Engineering
The demand for rare earth elements (REEs) has increased over the last decade due to applications in high technology devices including those in the defense industry. The recovery of REEs from primary sources such as rare earth minerals are viable using physical separations followed by chemical processing. However, weak market values and environmental concerns have limited the viability of such operations. On the other hand, REE recovery from secondary sources such as apatite ore, bauxite waste, and waste recycling, provides an opportunity to take advantage of a resource that does not require mining costs as well as other associated costs …
A Critical Assessment On The Resources And Extraction Of Rare Earth Elements From Acid Mine Drainage, Christopher R. Vass
A Critical Assessment On The Resources And Extraction Of Rare Earth Elements From Acid Mine Drainage, Christopher R. Vass
Graduate Theses, Dissertations, and Problem Reports
Rare earth elements (REEs) are crucial to many modern products used in both civilian and defense applications. Currently, a reliable supply of these elements is uncertain with the clear majority of REE production and refining occurring predominately in China. Furthermore, domestic ore deposits with commercially attractive concentrations of REEs are uncommon in the United States. As a result, the identification of a domestic supply of these technology metals is essential not only for manufacturing consumer merchandise but also for national security. Recently, one promising source of REEs has been identified: coal and coal-byproducts. One of those is acid mine drainage …
Time-Dependent Deformation And Associated Failure Of Roof In Underground Mines, Yuting Xue
Time-Dependent Deformation And Associated Failure Of Roof In Underground Mines, Yuting Xue
Graduate Theses, Dissertations, and Problem Reports
In underground coal mines, roof falls are a major contributor to injuries and fatalities. Studies have related the occurrence of roof fall to weak immediate roof, high horizontal stress, entry orientation, etc. An often-neglected factor in studies on this topic has been the influence of time-dependent behavior of the roof rock on roof falls. The time-dependent roof failure activity involves both intact and failed rocks. Numerical simulation techniques are available that include time-dependent behavior; however, they lack constitutive models that consider both the intact and the failed behavior of rock. In addition, input properties for the creep models only include …
Characterization Of Aerosols In An Underground Mine, Arash A. Habibi
Characterization Of Aerosols In An Underground Mine, Arash A. Habibi
Doctoral Dissertations
“Diesel-powered engines are a common source of submicron carbon-rich particles. Characterizing morphological and physical attributes of diesel agglomerates is therefore of great importance to be able to identify the source and improve removal technology. Size-segregated sampling was conducted in two phases of underground experiments. Scanning transmission electron microscopy and fast mobility particle sizers were used to determine the size distribution of agglomerates based on particle mobility and projected area diameter. Controlled zone sampling test results were used to determine the morphological characteristics of agglomerates for specific types of diesel equipment both with and without removal strategies. Changes in fractal dimension, …
Effectiveness Evaluation Of Fluorescent Tracer In Shaly-Sandstone Reservoir, Harid Pataveepaisit
Effectiveness Evaluation Of Fluorescent Tracer In Shaly-Sandstone Reservoir, Harid Pataveepaisit
Chulalongkorn University Theses and Dissertations (Chula ETD)
In petroleum exploration and production industry, tracer is a compound added to injected fluids, and can be easily detected even in a trace amount. Fluorescein sodium, a chemical tracer that can illuminate upon receiving a specific wavelength of light, was mentioned by several literatures due to its strong fluorescence at low concentration, non-toxicity, and non-biodegradability. In this study, fluorescein sodium in the form of fluorescein solution was evaluated with shaly-sandstone to observe their interactions. The first half of this study focused on the evaluation of the chemical characteristics of fluorescein. First, the detection limit of fluorescein solution in deionized water …
Investigation Of Long Term Pillar Stability In An Abandoned Gypsum Mine Based On Dissolution Models, Mohammadhossein Sadeghiamirshahidi
Investigation Of Long Term Pillar Stability In An Abandoned Gypsum Mine Based On Dissolution Models, Mohammadhossein Sadeghiamirshahidi
Dissertations, Master's Theses and Master's Reports
The abandoned Domtar Mine in Grand Rapids, MI underlies Interstate I-196. The mine operated for over 140 years, mining a 30-meter-deep, four-meter thick gypsum seam. In 2000, the mine was abandoned with the removal of the mine’s dewatering pumps allowing groundwater to flood the mine. The initial flooding resulted in saturating the mine pillars along with some amount of pillar dissolution. Overtime, gypsum dissolution would cease as the water becomes saturated with the gypsum dissolution products. The mine, however, is located adjacent to the Grand River and has groundwater moving through the mine resulting in the potential for continuing dissolution. …
Improving Base Metal Electrowinning, Charles Ebenezer Abbey
Improving Base Metal Electrowinning, Charles Ebenezer Abbey
Doctoral Dissertations
"In zinc electrowinning, Mn oxidizes to form MnO2 on Pb-Ag anodes, cell walls and pipes. MnO2 reduces anode corrosion but also leads to short circuits and maintenance issues. MnO2 is thought to interact with chloride ions and produce oxidized chlorine species. The interactions between Mn and Cl are not well understood. Bench scale experiments were conducted to investigate the effects of the manganese to chloride ratio on anode corrosion rate and electrolyte chemistry using rolled Pb-Ag anodes. Increasing the average Mn/Cl- ratio from ~7:1 to ~11:1 reduced the anode corrosion rate. Anode scales produced with Mn/Cl …
Simplifying Techniques Applied To Computational Fluid Dynamics Modeling Of Methane Explosions, Laura Steeves
Simplifying Techniques Applied To Computational Fluid Dynamics Modeling Of Methane Explosions, Laura Steeves
Theses and Dissertations--Mining Engineering
Traditional methods of studying underground coal mine explosions are limited to observations and data collected during experimental explosions. These experiments are expensive, time-consuming, and require major facilities, such as the Lake Lynn Experimental Mine. The development of computational fluid dynamics (CFD) modeling of explosions can help minimize the need for large-scale testing. This thesis utilized the commercial CFD software, SC/Tetra, to examine three case studies. The first case study modeled the combustion of methane in a scaled shock tube, measuring approximately 1 foot by 1 foot, by 20.5 feet long, with a methane cloud of 2.5 feet in length, at …
Operation And Process Control Development For A Pilot-Scale Leaching And Solvent Extraction Circuit Recovering Rare Earth Elements From Coal-Based Sources, Douglas Kweku Addo
Operation And Process Control Development For A Pilot-Scale Leaching And Solvent Extraction Circuit Recovering Rare Earth Elements From Coal-Based Sources, Douglas Kweku Addo
Theses and Dissertations--Mining Engineering
The US Department of Energy in 2010 has identified several rare earth elements as critical materials to enable clean technologies. As part of ongoing research in REEs (rare earth elements) recovery from coal sources, the University of Kentucky has designed, developed and is demonstrating a ¼ ton/hour pilot-scale processing plant to produce high-grade REEs from coal sources. Due to the need to control critical variables (e.g. pH, tank level, etc.), process control is required. To ensure adequate process control, a study was conducted on leaching and solvent extraction control to evaluate the potential of achieving low-cost REE recovery in addition …
Influence Of Water Injection Rate On The Vortecone, An Impingement Screen, And A Conventional Filter Screen Cleaning Efficiency, Oscar Velasquez
Influence Of Water Injection Rate On The Vortecone, An Impingement Screen, And A Conventional Filter Screen Cleaning Efficiency, Oscar Velasquez
Theses and Dissertations--Mining Engineering
Industrial produced respirable particles are known to affect the respirable tract of workers causing serious illness or even death. These particles can be found in any mining operation’s environment, new regulations by the Mine Safety and Health Administration (MSHA) in 2014 reduced the allowable limit of dust exposure for underground workers. Dust control practices have been improving over the years to lower the number of incidents caused by these particles. In underground mining, water sprays and scrubber systems have become the most used dust control methods. Water sprays create numerous fine water droplets to capture dust once it has become …
Dust Transportation And Settling Within The Mine Ventilation Network, Anand Kumar
Dust Transportation And Settling Within The Mine Ventilation Network, Anand Kumar
Theses and Dissertations--Mining Engineering
Dust is ubiquitous in underground mine activities. Continuous inhalation of dust could lead to irreversible occupational diseases. Dust particles of size lower than 75.0 µm, also known as float coal dust, can trigger a coal dust explosion following a methane ignition. Ventilation air carries the float coal dust from the point of production to some distance before it’s deposited on the surfaces of underground coal mine. Sources of dust are widely studied, but study of dust transportation has been mainly based on experimental data and simplified models. An understanding of dust transportation in the mine airways is instrumental in …
Thermodynamic Modeling And Equilibrium System Design Of A Solvent Extraction Process For Dilute Rare Earth Solutions, Alind Chandra
Thermodynamic Modeling And Equilibrium System Design Of A Solvent Extraction Process For Dilute Rare Earth Solutions, Alind Chandra
Theses and Dissertations--Mining Engineering
Rare earth elements (REEs) are a group of 15 elements in the lanthanide series along with scandium and yttrium. They are often grouped together because of their similar chemical properties. As a result of their increased application in advanced technologies and electronics including electric vehicles, the demand of REEs and other critical elements has increased in recent decades and is expected to significantly grow over the next decade. As the majority of REEs are produced and utilized within the manufacturing industry in China, concerns over future supplies to support national defense technologies and associated manufacturing industries has generated interest in …
Fundamental Mechanism Of Time Dependent Failure In Shale, Neel Gupta
Fundamental Mechanism Of Time Dependent Failure In Shale, Neel Gupta
Graduate Theses, Dissertations, and Problem Reports
In underground coal mines, mining activity disturbs the natural equilibrium state of in-situ stresses. The induced and in-situ stresses deform the rockmass surrounding the mine openings. Primary roof supports impede the deformation of the rockmass overlying the entries. However, failure can occur in the bolted rockmass, causing fatalities and injuries. The rockmass failure is erratic, and its occurrence often varies from a few days to months and years after the opening of the entry. One of the often-neglected factors in this process is the effect of time on the stability of mine openings, which can often be observed in the …
Social Impacts Of Climate Change And Occupational Heat Stress And Adaptation Strategies Of Mining Workers In Ghana, Victor Fannam Nunfam
Social Impacts Of Climate Change And Occupational Heat Stress And Adaptation Strategies Of Mining Workers In Ghana, Victor Fannam Nunfam
Theses: Doctorates and Masters
Excessive heat exposure due to rising temperatures associated with climate change adversely affects workers’ health, safety, productivity, and psychosocial well-being in occupational settings. In the hot and tropical regions of developing countries, long hours of physically demanding work, coupled with inadequate adaptation policies to climate change, increases the occurrence of heat-related illnesses and injuries, and contributes to the loss of productive capacity, poor decision making, and other negative effects on the social well-being of workers.
Based on the theories of social impact assessment, risk assessment, adaptation and resilience planning, this study assesses the social impacts of climate change and occupational …
Removal Of Antimony And Bismuth From Copper Electrorefining Electrolyte By Two Proprietary Solvent Extraction Extractants, Andrew Artzer
Removal Of Antimony And Bismuth From Copper Electrorefining Electrolyte By Two Proprietary Solvent Extraction Extractants, Andrew Artzer
Masters Theses
"Antimony and bismuth are two of the most problematic impurities in copper electrorefining (ER). Because of this, much research has been done investigating the ways to remove them. Processes that are currently being used industrially include anode additions, liberators, ion exchange (IX), and solvent extraction (SX). Of these, liberators and anode additions are the most common while SX is the least, mostly being used for arsenic removal. There are other methods that have been evaluated, but are not in commercial use. These include the use of various electrolyte additives, and adsorbents such as bentonite clay and heavy metal sulfates.
Two …
Projectile Impact Effects On A 50 Psi Plug Type Coal Mine Seal, Bruce Albert Von Niederhäusern
Projectile Impact Effects On A 50 Psi Plug Type Coal Mine Seal, Bruce Albert Von Niederhäusern
Masters Theses
"The current lack of projectile damage criteria for mine seals is assessed to determine if criteria should be developed. Impact experiments were performed on a full-scale 50 psi mine seal to determine failure modes, dynamic stress state, and assess risk to existing operational mine seals. Test projectiles were selected from common underground coal mine items propelled by means of a black powder projectile generator. Projectile velocities attained in testing ranged from approximately 100 to 650 ft/s (30 to 200 m/s). Dynamic strain was measured on the non-impact face to derive the state of stress and estimate failure criteria. Penetration models …
Pre-Feasibility Study Of Improving Quality Of Low-Grade Fluorite. A Case Study At Phanomthuan Deposit, Kanchanaburi, Thailand, Keosaychai Souvannavong
Pre-Feasibility Study Of Improving Quality Of Low-Grade Fluorite. A Case Study At Phanomthuan Deposit, Kanchanaburi, Thailand, Keosaychai Souvannavong
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this study was presented the pre-feasibility study of improving quality of low-grade fluorite from Phanomthuan deposit, Kanchanaburi province, Thailand. The purpose of this study aims to explore the optimal condition in order to remove the impurities which contained high SiO2, CaCO3 and other minerals, also evaluate the project in term of economic. Therefore, the improvement quality of fluorite by using froth flotation techniques was reach the ceramic grade. The raw material characterization contains CaF2 = 29.4 Wt.%, SiO2 = 43.9 Wt.% and CaCO3 = 6.9 Wt.%. After flotation process the optimal condition result which contains CaF2 = 96.46 Wt.%, …
The Behavior Of Suas Under Explosive Loading Conditions And Implications For Safe Operating Procedures, Ashok Em Sudhakar
The Behavior Of Suas Under Explosive Loading Conditions And Implications For Safe Operating Procedures, Ashok Em Sudhakar
Doctoral Dissertations
"Drones are increasingly being used for tasks previously unimagined and the beneficial uses are evolving. The United States Congress has envisioned the possible uses of drones for both combating and conveying explosive threats and other harmful and destructive activities. Congress' intent is reflected in new laws (2018) and policies (2019).
All civilian available Small Unmanned Aerial Systems sUASs (Drones), weighing less than 55 pounds, in the current market are not designed for operations in explosive environments. This first of a kind research focuses on further understanding of sUASs response to explosive loading and the public policy implications. This research measured …
Pressure Versus Impulse Graph For Blast-Induced Traumatic Brain Injury And Correlation To Observable Blast Injuries, Barbara Rutter
Pressure Versus Impulse Graph For Blast-Induced Traumatic Brain Injury And Correlation To Observable Blast Injuries, Barbara Rutter
Doctoral Dissertations
"With the increased use of explosive devices in combat, blast induced traumatic brain injury (bTBI) has become one of the signature wounds in current conflicts. Animal studies have been conducted to understand the mechanisms in the brain and a pressure versus time graph has been produced. However, the role of impulse in bTBIs has not been thoroughly investigated for animals or human beings.
This research proposes a new method of presenting bTBI data by using a pressure versus impulse (P-I) graph. P-I graphs have been found useful in presenting lung lethality regions and building damage thresholds. To present the animal …
Investigating Blast Fume Propagation, Concentration And Clearance In Underground Mines Using Computational Fluid Dynamics (Cfd), Raymond Ninnang Tiile
Investigating Blast Fume Propagation, Concentration And Clearance In Underground Mines Using Computational Fluid Dynamics (Cfd), Raymond Ninnang Tiile
Doctoral Dissertations
"Blasting activities using standard industry explosives is an essential component of underground hard rock mining operations. Blasting operations result in the release of noxious gases, presenting both safety and productivity threats. Overestimation of post-blast re-entry time results in production losses, while underestimation leads to injuries and fatalities. Research shows that most underground mines simply standardize post-blast re-entry times based on experiences and observations. Few underground mines use theoretical methods for calculating post-blast re-entry time. These theoretical methods, however, are unable to account for the variations in the blasting conditions. Literature review shows that: (i) there is currently no means of …
The Mechanics Of Precision Presplitting, Anthony Joseph Konya
The Mechanics Of Precision Presplitting, Anthony Joseph Konya
Doctoral Dissertations
"Precision Presplitting is a widely used method of presplit blasting for the mining and construction industries. In recent years considerable effort has gone into the development of empirical equations based on field data to be able to better design the Precision Presplit for various rock types and structural environments. However, the most widely discussed theory about the mechanics of the presplit formation, that of shockwave collisions, does not appear to be applicable for this method of presplitting.
This research has disproven this theory based on insufficient magnitude of the shockwave from modeling with basic wave mechanics. Other authors have suggested …
Multi-Body Dynamic And Finite Element Modeling Of Ultra-Large Dump Truck - Haul Road Interactions For Machine Health And Haul Road Structural Integrity, Bruno Ayaga Kansake
Multi-Body Dynamic And Finite Element Modeling Of Ultra-Large Dump Truck - Haul Road Interactions For Machine Health And Haul Road Structural Integrity, Bruno Ayaga Kansake
Doctoral Dissertations
"Haul truck capacities have increased due to their economies of scale in large-scale surface mine production systems. Ultra-large trucks impose high dynamic loads on haul roads. The dynamic loads are exacerbated by road surface roughness and truck over-loading. The dynamic forces also subject trucks to high torsional stresses, which affect truck health. Current haul road response models are 2D and use static truckloads for low capacity trucks. Existing 3D models consider the road as a two-layer system. No models capture the truck dynamic effects on haul roads and predict strut pressures during haulage.
Lagrangian mechanics was used to formulate the …
Correlation Development Of Wax Deposition Prediction From Fang Oil Field, Aung Thwin Thu Aye
Correlation Development Of Wax Deposition Prediction From Fang Oil Field, Aung Thwin Thu Aye
Chulalongkorn University Theses and Dissertations (Chula ETD)
In petroleum industry, wax deposition is a critical operational challenge. It occurs in various locations in the petroleum production chain including well tubing. Hexane, chemical inhibitor, is used to prevent the wax problem of oil from Fang oilfield by the measurement of pour point, wax appearance temperature (WAT) and wax deposition. An increasing shear rate can reduce WAT and the deposited amount increases with lowering the temperature in Fang crude oil. Moreover, the non-linear regression analysis of Fang crude oil with and without hexane in different conditions are done for all three tests. Those regression analysis equations can predict WAT …
Ore Reserve Estimation By Using A Geostatistical Tool At Heinda Mine,Tanintharyi Region,Union Of Myanmar, Aye Min Tun -
Ore Reserve Estimation By Using A Geostatistical Tool At Heinda Mine,Tanintharyi Region,Union Of Myanmar, Aye Min Tun -
Chulalongkorn University Theses and Dissertations (Chula ETD)
Heinda mine is one of major tin producers in Myanmar. The mine has been operated for over 100 years. The mine falls at Latitude 14° 8’ N and Longitude 98° 27’ E, approximately about 45 kilometers to the east of Dawei. The ore reserve is the principal factor of mining venture. The aim of this study is to improve the ore reserve estimation by using geostatistical method (ordinary kriging) compared with conventional method (polygonal method) In geostatistical evaluation, it involved variogram analysis, variogram modelling and kriging estimation. The exponential variogram modelling was used to calculate the ordinary kriging estimation. The …
Pre-Feasibility Study On Granite Quarry For Aggregate: A Case Study At Kanchanaburi Province, Thailand, Bee Ziyivang
Pre-Feasibility Study On Granite Quarry For Aggregate: A Case Study At Kanchanaburi Province, Thailand, Bee Ziyivang
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study aims to develop long term mine planning and design, equipment requirement calculation, and financial model analysis of mining and crushing plant. The ore reserve estimation and pit design carried out by using MineSight software (Ver. 9.50). A discounted cash flow model (DCF) and sensitivity analysis used to evaluate the financial project. Based on our study, the open-pit mining method was advisable for mine planning and design. Ore reserve estimated to 48.4 Mtons under the mining operation of 2.4 Mtos per year. The project time frame is 22 years which spends 21 years for operation and one year for …