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Browsing by Author "Craynon, John Raymond"

Now showing 1 - 6 of 6
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    Approaches and Barriers to Incorporating Sustainable Development Into Coal Mine Design
    Craynon, John Raymond (Virginia Tech, 2011-07-27)
    It is widely recognized that coal is and will continue to be a crucial element in a modern, balanced energy portfolio, providing a bridge to the future as an important low-cost and secure energy solution to sustainability challenges. The designer of coal mining operations needs to simultaneously consider legal, environmental, and sustainability goals, along with traditional mining engineering parameters, as integral parts of the design process. However, traditional coal mining planning seldom considers key “sustainability factors” such as societal impacts; dislocation of towns and residences; physical and economic impact on neighboring communities and individuals; infrastructure concerns; post-mining land use habitat disruption and reconstruction; and long-term community benefit. This work demonstrates the advantage of using a systems engineering approach based on the premise that systems can only be optimized if all factors are considered at one time. Utilizing systems engineering and optimization approaches allows for the incorporation of regulatory and sustainability factors into coal mine design. Graphical approaches, based on the use of GIS tools, are shown as examples of the development of models for the positive and negative impacts of coal mining operations. However, this work also revealed that there are significant challenges inherent in optimizing the design of large-scale surface coal mining operations in Appalachia. Regulatory and permitting programs in the United States, which give conflicting and ill-defined responsibilities to a variety of federal and state agencies, often focus on single parameters, rather than the full suite of desirable outcomes for sustainability, and serve as barriers to innovation. Sustainable development requires a delicate balance between competing economic, environmental and social interests. In the context of coal mining in the U.S., the current regulatory frameworks and policy-guidance vehicles impede this balance. To address this problem, and thus effectively and efficiently provide energy resources while protecting the communities and environments, the U.S. will likely need to fundamentally restructure regulatory programs. Ideally, revisions should be based upon the key concepts of public ecology and allow for a systems engineering approach to coal mine design.
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    The collectorless flotation of sphalerite
    Craynon, John Raymond (Virginia Tech, 1985-07-05)
    The flotation of sphalerite has been demonstrated without the use of collectors. The effect of redox potential, pH, and copper-activation have been investigated in tests using samples of pure mineral. It has been found that in general, collectorless flotation of sphalerite can be accomplished at potentials greater than -200 mV, SHE, and is more readily carried out in acidic solutions. It has also been shown that although copper-activation was necessary to achieve flotation recoveries above 35%, an excessive addition of cupric ions may result in a decrease in floatability. Batch flotation experiments conducted using Elmwood Mine sphalerite ore have shown that in addition to copper-activation, the addition of sodium sulfide was required to obtain high grades and recoveries. If the ratio of the addition of these reagents is maintained such that the atomic ratio of cupric ions to sulfide ions is 0.31, good flotation is observed over a range of reagent dosages. X-ray photoelectron spectroscopy (XPS) was conducted on pure mineral samples after microflotation testing. Based on the sulfur species identified on highly flotable samples, possible mechanisms for collectorless flotation of sphalerite have been suggested. These include: i) elemental sulfur formed under oxidizing conditions is responsible for collectorless flotation; ii) polysulfides or metal-deficient sulfides formed as a result of mineral oxidation are responsible for collectorless flotation; and iii) removal of HS- ions, which may render the surface hydrophilic, under oxidizing conditions. The third mechanism is based on the assumption that clean, unoxidized sphalerite surfaces are naturally hydrophobic. Evidence has been presented to suggest that the first mechanism may be responsible for collectorless flotation in acidic solutions, while the second mechanism may be of greater importance in nearly neutral or basic solutions where elemental sulfur is thermodynamically less stable.
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    The Effects of Microhabitat and Land Use on Stream Salamander Occupancy and Abundance in the Southwest Virginia Coalfields
    Sweeten, Sara (Virginia Tech, 2015-04-09)
    Large-scale land uses such as residential wastewater discharge and coal mining practices, particularly surface coal extraction and associated valley fills, are of particular ecological concern in central Appalachia. Identification and quantification of both large-scale land use and microhabitat alterations to ecosystems are a necessary first-step aid in mitigation of negative consequences to biota. In central Appalachian headwater streams absent of fish, salamanders are the dominant, most abundant vertebrate predator providing a significant intermediate trophic role. Stream salamander species are considered to be sensitive to aquatic stressors and environmental alterations with past research having shown linkages among microhabitat parameters, and large-scale land use such as urbanization and logging to salamander abundances. However, there is little information examining these linkages in the coalfields of central Appalachia. In the summer of 2013, I visited 70 sites (sampled three times each) in the southwest Virginia coalfields to collect salamanders and quantify stream and riparian microhabitat parameters. In an information-theoretic framework I compared the effects of microhabitat and large-scale land use on salamander occupancy and abundances. My findings indicate that dusky salamander (Desmognathus spp.) occupancy and abundances are more correlated to microhabitat parameters such as canopy cover than to subwatershed land uses. Brook salamander (Eurycea spp.) occupancy show negative associations to large-scale land uses such as percent recent mining and percent forested. Whereas Eurycea spp. abundances are negatively influenced by suspended sediments, stream bank erosion and stream substrate embeddedness. Management implications of these findings include erosion prevention and control as well as protection and management of riparian habitats. However, quantifying physical environmental quality such as stream and riparian habitat often can be quite difficult, particularly when there are time or fiscal limitations. In order to accurately assess stream and riparian habitat in a time- and cost- effective manner, the U.S. Army Corps of Engineers (USACE) developed a functional condition index (FCI) assessment for streams that measures 11 stream and riparian parameters along with watershed land use to calculate three different scores: a hydrology score, biogeochemical score, and habitat score (Noble et al 2010). Using the salamander data from 2013, I then analyzed the FCI scores using collected occupancy and abundance analyses. Both analyses supported the Habitat FCI score as it had strong correlations with both occupancy and abundance of three Desmognathus spp., and support the use of the USACE protocol for stream and riparian habitat assessment.
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    The Prediction and Occurrence of Chimney Subsidence in Southwestern Pennsylvania
    Dyne, Laura Anne (Virginia Tech, 1998-01-23)
    Coal mining in Pennsylvania has long been an important factor in the economic development of the commonwealth. However, the mines abandoned before today's strict environmental regulations have degraded over half of Pennsylvania's counties. Subsidence incidents, known as chimney caves, are in the form of sinkholes and develop above abandoned room-and-pillar mines. Chimney caving is the most dominant type of subsidence in southwestern Pennsylvania, yet there are no accurate means available to predict their occurrences. Therefore, an investigation has been conducted in order to develop a set of engineering criteria, or an equation, to predict such occurrences. Through conducting sand model experiments and through the collection of a chimney subsidence incident database, such an equation was derived, and verified using actual field data.
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    Risk Management in the Extractive Industries: Environmental Analysis and Mitigation
    Smith, Sean P. (Virginia Tech, 2014-02-19)
    Risk management has been used regularly in the mining industry over the last few decades. The majority of those instances have focused on health and safety issues. Health and safety has improved in the United States, Australia, and other major mining districts because of the successful use of risk management and mitigation practices. Risk management has been used to a lesser extent to reduce or avoid environmental issues as well. There are a number of factors that make utilization of risk management analysis more applicable to health and safety than to environmental issues. This thesis explores the use of risk management in the context of environmental issues associated with mining. Specifically, two case studies are developed in two self-contained manuscripts: the first focuses on sequestering CO2 while the second focuses on wild rice in Minnesota with regards to the sulfate standard. Through the lens of risk management, an attempt is made to align project goals and efforts with mitigation potential to reduce the likelihood or result of particular risks. The end result is a reduction in risks due to mitigation. The first manuscript shows how risks disappear over time because they have been categorized and addressed. The project goals are keep on track by eliminating or reducing these risks. The second manuscript can be used by stakeholders to review their potential risks and mitigate those risks if possible/necessary. In contrast to the first manuscript that contains risks that are known and measurable, the second manuscript examines different risks based on four potential outcomes.
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    Surface Water Impacts from Active Underground Mining
    Kirby, Laura Rebecca (Virginia Tech, 2013-07-03)
    High extraction mining techniques have produced the need to mitigate and understand ground movements associated with this technology.  Tools such as the Surface Deformation Prediction System (SDPS) facilitate sound scientific decision making in the industry and has continually improved since its inception in 1987.  The capabilities of SDPS have expanded on an as-needed basis.  Currently, the regulatory climate has emphasized the need to understand the impact of underground mining on surface waters, physically and chemically. The SDPS program is used to conduct an analysis of ground movements to assess optimal barrier pillar size for stream protection.  Typical analytical and empirical methods used in mine planning were compared against SDPS methods to ensure the validity and advantage to the use of SDPS for this purpose. Finally, underground mining effects on stream chemistry and health were explored by studying the heavily mined and industrialized watershed of Dumps Creek located in Russell County, Virginia.  This watershed has been identified as being impaired since the Virginia 303(d) List of Impaired Waters was created in 1994.  Currently, there are two pumps staged in the headwaters region of Dumps Creek that help to maintain water levels in an inactive underground mine.  The pumping is necessary to control methane levels that rising water could force into an active underground mine that lies stratigraphically above the inactive mine.  Water is pumped on an as-needed basis and discharges directly into Dumps Creek.  Historic measurements of stream conductivity and benthic health scores were compared to assess whether a correlation exists between the two measurements.  These measurements were compared based on regulatory decisions that emphasized that conductivity is a direct indicator of stream health in all watersheds. Scientific contributions associated with this research include: Further developments in the use of SDPS programming in order to account for stream protection on a case by case basis for both mine panel and surface water protection by optimizing barrier pillar size in relation to a nearby stream; the analysis of available and currently obtained water chemistry data in a mining impacted watershed in attempt to further research to appropriately characterize and mitigate specific problems in order to improve stream health; and, assessment of the complexity of water chemistry impacts from underground mining as related to stream health indicators in different chemically dominated watersheds.