Scholarly Works, Mining and Minerals Engineering

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https://hdl.handle.net/10919/24291

Research articles, presentations, and other scholarship

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A conceptual protocol for integrating multiple parameters for risk assessment due to induced seismicity in a deep mine
Ghaychi Afrouz, Setareh; Westman, Erik C.; Dehn, K. K.; Weston, B.; Luxbacher, Kramer Davis (2020-01-01)
Typically, the time-dependent b-value has been shown to decrease prior to the occurrence of a higher-magnitude event, thus providing a possible indicator of the timing of a significant event. The Energy Index relates seismic energy to seismic moment and an increase in the Energy Index has been associated with an increase in rock mass stress levels. The distribution of P-wave velocity also indicates rock mass stress levels and is provided from time-lapse passive seismic tomography. Finally, prior studies have correlated an increased production rate (blast rate) to higher stress concentrations, potentially triggering a seismic event. Therefore, Energy Index, P-wave velocity, and blast rate may be correlated to stress levels within the rock mass and may imply the magnitude and timing of an event. In this case study, these parameters are used in a back analysis to define a safety protocol for a deep, narrow-vein, underground mine. A catalog of b-value, Energy Index, P-wave velocity, and mine excavation blasting rate, was developed and integrated as a concept of hazardous thresholds. The combination of these various parameters can be helpful in determining the potential for high-risk times and locations due to induced stress.
Considerations for an Automated SEM-EDX Routine for Characterizing Respirable Coal Mine Dust
Johann, Victoria Anne; Sarver, Emily A. (2015)
Respirable dust in coal mining environments has long been a concern for occupational health. Over the past several decades, much effort has been devoted to reducing dust exposures in these environments, and rates of coal workers’ pneumoconiosis (CWP) have dropped significantly. However, in some regions, including parts of Central Appalachia it appears that incidence of CWP has recently been on the rise. This trend is yet unexplained, but a possible factor might be changes in specific dust characteristics, such as particle composition, size or shape. Prior work in our research group has developed a standardized methodology for analyzing coal mine dust particles on polycarbonate filter media using scanning electron microscopy with energy dispersive x-ray (SEM-EDX). While the method allows individual particles to be characterized, it is very time-intensive because the instrument user must interrogate each particle manually; this limits the number of particles that can practically be characterized per sample. Moreover, results may be somewhat user-dependent since classification of particle composition involves some interpretation of EDX spectra. To overcome these problems, we aim to automate the current SEM-EDX method. The ability to analyze more particles without user bias should increase reproducibility of results as well as statistical confidence (i.e., in applying characteristics of the analyzed particles to the entire dust sample.) Some challenges do exist in creating an automated routine, which are primarily related to ensuring that the available software is programmed to differentiate individual particles from anomalies on the sample filter media, select and measure an appropriate number of particles across a sufficient surface area of the filter, and classify particle compositions similarly to a trained SEM-EDX user following a manual method. This paper discusses the benefits and challenges of an automated routine for coal mine dust characterization, and progress to date toward this effort.
Considerations for TGA of Respirable Coal Mine Dust Samples
Scaggs, Meredith; Sarver, Emily A.; Keles, Cigdem (2015)
Respirable dust in coal mining environments has long been a concern for occupational health. Over the past several decades, much effort has been devoted to reducing dust exposures in these environments, and rates of coal workers’ pneumoconiosis (CWP) have dropped significantly. However, in some regions, including parts of Central Appalachia it appears that incidence of CWP has recently been on the rise. This trend is yet unexplained, but a possible factor might be changes in specific dust characteristics, such as particle composition, size or shape. Prior work in our research group has developed a standardized methodology for analyzing coal mine dust particles on polycarbonate filter media using scanning electron microscopy with energy dispersive x-ray (SEM-EDX). While the method allows individual particles to be characterized, it is very time-intensive because the instrument user must interrogate each particle manually; this limits the number of particles that can practically be characterized per sample. Moreover, results may be somewhat user-dependent since classification of particle composition involves some interpretation of EDX spectra. Respirable dust in underground coal mines has long been associated with occupational Jung diseases, particularly coal workers' pneumoconiosis (CWP) and silicosis. Regular dust sampling is required for assessing occupational exposures , and compliance with federal regulations is determined! on the basis of total respirable dust concentration and crystalline silica content by mass. In light of continued incidence of CWP amongst coal miners, additional information is needed to determine what role specific dust characteristics might play in health outcomes . While particle-level analysis is ideal, current time requirements and costs make this simply unfeasible for large numbers of samples. However, opportunities do exist for gleaning additional information from bulk analysis (i.e., beyond total mass and silica content) using relatively quick and inexpensive methods. Thermogravimetric analysis (TGA) may be a particularly attractive option. It involves precise sample weight measurement in a temperature controlled environment, such that weight changes over specific temperature ranges can be correlated to cheruical changes of particular sample constituents. In principle, TGA offers the ability to determine the coal and total mineral mass fractions in respirable dust samples. Such analysis could conceivably be combined with standard methods currently used to measure total mass and silica content. Under some circumstances , TGA might also be extended to provide information on specific dust constituents of interest (such as calcite). In this paper, we consider the benefits and challenges of TGA of respirable coal mine dust samples, and provide preliminary results and observations from ongoing research on this topic.
DPM Monitoring in Underground Metal/Nonmetal Mines
McCullough, E.; Rojas-Mendoza, L.; Sarver, Emily A. (2015)
An innovative methodology for the assessment and maintenance of e-learning courses using the Community of Inquiry model
Luxbacher, Kray; Stinnette, J. Daniel (Taylor & Francis, 2021-06-14)
As part of the creation of the series of online, asynchronous learning courses developed for the community of underground ventilation practitioners (Aeolus Modules), the authors have developed an innovative plan for the assessment and maintenance of these courses by leveraging the skills and experience of the existing and active membership of the Underground Ventilation Committee and applying them to the Community of Inquiry model. This process involves the triggering events of the module users (students) to identify weaknesses and deficiencies within the course(s) material, and to guide the development of additional content, while expert users and course developers use the learners’ inputs to make necessary revisions and create new and expanded content in the most efficient manner. By working together, and communicating directly through a framework established explicitly for that purpose (i.e., listserves, chatrooms, direct messaging, etc.) the process of content revision and creation can be optimized by letting the end user directly communicate their needs to the developers and become active participants not only in the consumption, but in the creation of their own educational resource(s).
Preliminary Investigation of DPM Scavenging by Water Sprays
Rojas-Mendoza, L.; McCullough, E.; Sarver, Emily A.; Saylor, J. R. (2015)
Reagents in coal processing: where do they go?
Morris, Josh; Sarver, Emily A.; Luttrell, Gerald H.; Novak, John T. (Canadian Institute Of Mining, Metallurgy And Petroleum, 2012-10)
A variety of reagents are utilized in coal preparation, but aside from performing their desired function relatively little is known about the behavior of these reagents within the processing circuits. Where exactly do reagents go once dosed? In this paper, we present preliminary results of partitioning studies on frother (i.e., MIBC) and collector (i.e., petro-diesel) chemicals commonly used in coal flotation, and examine implications for water management (e.g., in closed-loop systems). Additionally, we discuss the usefulness of such data in predicting environmental transport and fate of chemicals – which is currently a top priority for industry.
Review and simulation of passive seismic tomography in block cave mining
Ghaychi Afrouz, Setareh; Westman, Erik C. (Australian Centre for Geomechanics, Perth, 2018)
Seismic tomography methods are progressing in crustal seismology and at the smaller mining scale to recognise highly stressed or fracture-prone areas. Velocity variations measured by seismic tomography represent stress concentrations in the rock mass. Changes in these stress conditions are of interest in mining as they are linked to the instability of the underground openings. Rock fracturing generates seismic waves, which propagate with different velocities through portions of the rock mass that have different moduli. Both known and unknown seismic sources in mining environments generate active and passive tomography data, respectively. Active tomography utilises a known source time and location, while passive seismic tomography uses the mining-induced seismic events, for which the source time and location can only be estimated. Mining-induced seismic events generally have relatively low magnitudes, typically lower than ML = 3. The pattern of stress redistribution varies based on different mining methods at different depths. In this study, development of seismic tomography in the mining industry is traced through a review of background theory and recent applications. Additionally, a block caving simulation is presented, including the imaging of cave development, load distribution, and abutment zones. A simple elastic numerical model is used to model stress distribution surrounding a hypothetical block cave. Velocities are assigned to portions of the model corresponding to the stress level. With this velocity model, synthetic travel times are modelled. The synthetic travel times are then used as input to the tomography code. The velocity distribution, which is then generated through the tomography calculations, is compared to the initial, modelled velocity distribution providing a means for validating the quality of the results of the tomography approach for this application.
Towards Sustainable Development: Conflict Management Practice and Education
McCullough, Erin; Sarver, Emily A. (Society for Mining, Metallurgy and Exploration, 2016-02-22)
Fostering positive community relations is a principal tenet of sustainable development, but conflict can test even the strongest of relationships. While conflict surrounding resource development projects has the potential to be destructive, it may actually pose opportunities for partnership and collaboration when managed effectively. It is therefore not only important for mineral resource professionals to recognize the financial and social costs associated with legal disputes among project stakeholders, but also for them to prioritize resolving social conflict using alternative channels that allow for win-win outcomes. A variety of dispute prevention and resolution techniques do exist, but successful practice is not yet the norm. Here we review the sources and consequences of social conflict in the context of mining projects, and discuss typical and alternative approaches to conflict management in light of their respective benefits and drawbacks. We also suggest implementation of conflict resolution lessons into resource-related university curricula as a critical step in the continued shift of the mining industry towards sustainable development.

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