Mining Engineering Commons^™

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 …

Evaluation Of The 20 L Dust Explosibility Testing Chamber And Comparison To A Modified 38 L Vessel For Underground Coal, Robert Quentin Eades, Kyle A. Perry, Catherine E. Johnson, Jacob Miller

Mining Engineering Faculty Research & Creative Works

The phenomenon of combustible dust explosions is present within many industries. Tests for explosibility of dust clouds per ASTM E1226 use a 20 L explosive chamber that places the combustible dust directly below the dispersion nozzle which generates a thorough mixture for testing purposes. However, in the underground coal mining industry, there are a number of geologic, mining, and regulatory factors that change the deposition scheme of combustible coal dust. This causes the atmosphere of a coal mine to have a variable rock dust-coal dust mixture at the time of ignition. To investigate the impact of this variable atmosphere, a …

Study On The Effect Of Iron-Based Deoxidizing Inhibitors For Coal Spontaneous Combustion Prevention, Chaoyu Hao, Yanling Chen, Jiren Wang, Cunbao Deng, Guang Xu, Fengwei Dai, Rui Si, Hongfei Wang, Haoyu Wang

Mining Engineering Faculty Research & Creative Works

To improve the prevention of spontaneous coal combustion, reduced iron powder and other ingredients should be added together to form an iron-based deoxidizing inhibitor, with the dual effect of oxygen consumption and inhibition. The oxygen consumption rate of the inhibitor was studied through experiments. According to the theory of coordination resistance, the coordination resistance of Fe³⁺ was studied via the density functional method. Subsequently, a comparative experiment of the effects on spontaneous coal combustion was conducted. The research shows that several kinds of common resistance agents that are added to the reduced iron powder can consume oxygen. However, the …

Impact Of Nanobubbles On Mechanical Coal Flotation Process, Ahmed Sobhy, Dongping Tao

Mining Engineering Faculty Research & Creative Works

A bank of three 10-liter mechanical flotation cells integrated with nanobubble technology was investigated to assess the impact of nanobubbles on coal separation performance at different operating variables. The most significant operation parameters such as fuel oil collector dosage, methyl isobutyl carbinol (MIBC) frother concentration, flow rate to nanobubble generator, feed solid concentration, and feed flow rate were studied individually. Nanobubbles are generated selectively on the hydrophobic particles, which should have a positive effect on flotation separation efficiency. It has been shown that frother concentration, collector dosage, and flow rate to nanobubble generator had a positive and significant effect on …

Evaluation And Prevention Of Spontaneous Combustion During Handling And Storage Of Coal, Amir E. Najarzadeh

Theses and Dissertations--Mining Engineering

Spontaneous combustion of coal has historically been a major problem for the coal industry, predominantly during storage and transportation. Various methods have been used in the laboratory for evaluating the propensity of different coal sources to self-heat. However, the heterogeneity of coal and the complexity of the system has resulted in inconsistencies and sometimes conflicting results as indicated by the findings reported in several publications.

The primary objective of the current study was to build a laboratory scale apparatus that simulates the condition of a coal stockpile to evaluate the events leading to spontaneous combustion and develop potential remedies. As …

Parametric Study Of Coal Liberation Behavior Using Silica Grinding Media, Adewale Wasiu Adeniji

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study evaluates the coal liberation behavior using silica as the grinding media by assessing the effects of four operating factors including nominal feed size, media size, shaft speed and grinding time, each of three levels on two response variables, the product P₈₀ and the specific energy. The coal material used in this study was mixed-phase particles commonly referred to as middlings, sampled from dense medium circuit at the Leatherwood preparation plant in Kentucky. One-third fractional factorial design of resolution III was implemented. Since silica was obtained in three standard size ranges as per manufacturer’s design, media size was …

Time Effect Of Water Injection On The Mechanical Properties Of Coal And Its Application In Rockburst Prevention In Mining, Xiaofei Liu, Guang Xu, Chong Zhang, Biao Kong, Jifa Qian, Dong Zhu, Mingyao Wei

Mining Engineering Faculty Research & Creative Works

Coal seam water injection is widely used to prevent rockbursts in coal mines, and the duration of water injection is an important parameter related to the effectiveness of rockburst prevention, making it of practical importance to optimize the effective water injection duration. This paper presents the test results of the mechanical properties and pore structure of samples with different soaking time, obtained from a working face where rockburst occurred. Soaking time changes the mechanical properties of samples, and this time effect differs with the coal size (from centimeter to nanometer size). Results of numerical simulation and on-site tests in the …

Effects Of Loading Rate On Gas Seepage And Temperature In Coal And Its Potential For Coal-Gas Disaster Early-Warning, Chong Zhang, Xiaofei Liu, Guang Xu, Xiaoran Wang

Mining Engineering Faculty Research & Creative Works

The seepage velocity and temperature externally manifest the changing structure, gas desorption and energy release that occurs in coal containing gas failure under loading. By using the system of coal containing gas failure under loading, this paper studies the law of seepage velocity and temperature under different loading rates and at 1.0 MPa confining pressure and 0.5 MPa gas pressure, and combined the on-site results of gas pressure and temperature. The results show that the stress directly affects the seepage velocity and temperature of coal containing gas, and the pressure and content of gas have the most sensitivity to mining …

Determine The Potential Drill Utilization Improvements And Rock Fragmentation Requirements Using Directional Drilling In A Coal Mining Overburden Highwall Application, K. D. Dill, S. D. Rosenthal

Mining Engineering

This project analyzed the efficiency of incorporating the use of directional drilling technology into coal overburden blasting. Directional drilling is currently in use in the petroleum industry and it is believed that it will be a valuable asset in the mining industry. This project has shown that directional drilling can be a viable technology for use in the coal overburden removal process resulting in increased drill utilization and potential for cost savings. Future work regarding blasting and geotechnical evaluation should be performed to solidify the concept.

Evaluation & Selection Of Novel Surveying Systems For Use In Surface Coal Mining, M. Drake, C. Roos, P. Conrad, T. Stack

Mining Engineering

This paper presents the evaluation Montana Tech completed for the Western Energy Company Rosebud Mine relating to the benefits of survey data collected using novel technologies over traditional methods for topographic surveys. These technologies include Unmanned Aircraft Systems (UAS), photogrammetry, and laser scanning/LIDAR. Utilizing these technologies, large areas such as reclamation areas and cast blasts can be surveyed in a timely manner for use by the mining operation. The areas that were evaluated were the improvements in the safety of employees and the time required to collect data. In addition, there is also a potential cost savings for the operation, …

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 …

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 …

Characterizing The Variability In Respirable Dust Exposure Using Johnson Transformation And Re-Examining 2010 Proposed Changes To The U.S. Underground Coal Mine Dust Standard, Al I. Khan

Theses and Dissertations--Mining Engineering

Coal workers’ pneumoconiosis (CWP), commonly referred to as black lung, is a chronic lung disease that results from the inhalation and deposition of coal dust in the lungs. While this disease continues to afflict coal miners, its prevalence has steadily declined over three decades since 1970. Based on a voluntary X-ray surveillance program, conducted by the National Institute for Occupational Safety and Health (NIOSH), this downward trend, however, ended in 2000 and has actually begun to rise. The Mine Safety and Health Administration (MSHA) instituted a Comprehensive Initiative to “End Black Lung” to combat the reported upturn in black …

Cavitation Nanobubble Enhanced Flotation Process For More Efficient Coal Recovery, Ahmed S. Sayed Ahmed

Theses and Dissertations--Mining Engineering

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

Nanobubbles integrated into a specially designed column flotation expanded the particle size range for efficient froth flotation as a result of increased probabilities of particle- bubble collision and attachment and reduced probability of detachment.

The major advantages of nanobubble …

Day 3. Wednesday, August 13, 2003: Travel To Grand Junction, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

5 pages (includes color illustration and map).

Contains references.

A Knowledge-Based Expert System For Managing Underground Coal Mines In The U.S., H. Singh, S. Yuan, C. M. Watts, J. M. Dean, N. P. Reddy, R. S. Nutter Jr., R. Larry Grayson

Mining Engineering Faculty Research & Creative Works

The Mine Management Support System which is being developed as a knowledge-based expert system for better management of underground coal mines, is presented. Concentrating on capturing the complex body of knowledge needed to enhance efficient management of a mine, it will encompass information and preferred rules on work scheduling, work practices, regulations impinging on the accomplishment of work, responses to operating problems, and the labor-management work agreement. Different components of the mine system, modeled using an object-oriented layering technique, are displayed graphically to aid in coordinating work plans and to present locations of equipment, supplies, and proposed subsystem components.

Knowledge Organization And Inference Engine For The Wvu Face Decision Support System, S. Carrow, R. S. Nutter Jr., R. S. Raman, N. A. Reddy, Y. V. Reddy, R. Larry Grayson

Mining Engineering Faculty Research & Creative Works

The knowledge-based organization for the West Virginia University Face Decision Support System is given, along with the initial development of the associated inference engine. The knowledge base contains generic knowledge about underground coal mines that utilize continuous miners. A typical knowledge entry is given, and the inference engine methodology is explained. The engine utilizes this knowledge with data from monitoring systems and from interaction with the section foreman, to assist in making section management decisions and plans.

Leases For Other Minerals: Recent Developments, Thomas F. Cope

Public Lands Mineral Leasing: Issues and Directions (Summer Conference, June 10-11)

14 pages.

Contains references.

Agenda: Public Lands Mineral Leasing: Issues And Directions, University Of Colorado Boulder. Natural Resources Law Center

Public Lands Mineral Leasing: Issues and Directions (Summer Conference, June 10-11)

University of Colorado School of Law professor Lawrence J. MacDonnell served as the conference organizer and as a member of the faculty.

Federal leasing programs, especially for oil and gas and coal, have been undergoing important changes in recent years. This conference will provide an overview and an update for those involved in public lands mineral development. Significant new issues also will be addressed.

Agenda: Federal Lands, Laws And Policies And The Development Of Natural Resources: A Short Course, University Of Colorado. School Of Law, University Of Colorado Boulder. Natural Resources Law Center

Federal Lands, Laws and Policies and the Development of Natural Resources: A Short Course (Summer Conference, July 28-August 1)

Even before the [Natural Resources Law] Center was established [in the fall of 1981], the [University of Colorado] School of Law was organizing annual natural resources law summer short courses. To date four programs have been presented:

- July 1980: "Federal Lands, Laws and Policies and the Development of Natural Resources"

- June 1981: "Water Resources Allocation: Laws and Emerging Issues"

- June 1982: "New Sources of Water for Energy Development and Growth: lnterbasin Transfers"

- June 1983: "Groundwater: Allocation, Development and Pollution"

(Reprinted from Resource Law Notes, no. 1, Jan. 1984, at 1.)

Instructors for this conference included University …