Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"coal waste"”.
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Desulphurisation of fine coal waste tailings using algal lipids
… is an energy-driven economy which relies on coal to meet most of its energy demands. Coal mining has resulted in the generation of coal waste over 60 million tonnes, annually. Apart from the huge footprint of this waste, the sulphide minerals contained in the waste have resulted in the …
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Coal waste deposition and the distribution of freshwater mussels in the Powell River, Virginia
… species, quantify substratum composition and coal waste deposition, and to assess population trends during the last half century. Mussels were collected as far upstream as Powell River Mile (PRM) 167.4 near Dryden, Virginia. Endangered species were collected up to PRM 144.6 at Jonesville, …
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Correlations between the Mineralogy and Recovery Behavior of Rare Earth Elements (REEs) in Coal Waste
… recently regarding the recovery of REEs from coal-related materials, such as coal waste, acid mine drainage, and coal combustion ash. The recovery of REEs from coal waste has been investigated by the author in recent years, and it was found that after calcination at 600 ℃ for 2 h, a …
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Environmental Performance Assessment of Froth Flotation for Coal Recovery and Sulfur Removal from Ultrafine Coal Waste
The South African coal mining industry generates large volumes of coal ultrafine waste (< 150 microns) each year, with a significant amount being dumped in tailing slurry dams. These slurry dams have been associated with prolonged pollution and loss of valuable resources. In the two stage flotation …
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Early-stage design and development of mine waste valorisation technologies with expert input: a case study of South African sulfide-enriched coal waste
… of both valuable products and large bodies of waste, which are traditionally disposed of on land and carry environmental and social risks. Circular economy and resource efficiency trends have shifted the focus from disposal to waste reuse and recycling. Despite the benefits of the circular …
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Physical and chemical properties of coarse coal refuse from Southwest Virginia
Coarse coal refuse is difficult to reclaim due to high potential acidity and coarse fragment content, low water holding capacity, low fertility, and other problems. Little is known about coal refuse properties, particularly as they relate to revegetation potential. This study was undertaken to …
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An economic evaluation of backfilling in Virginia's coal mines
… to eliminate environmental problems caused by coal waste dumps, improve coal recovery, and improve mine ventilation. However, backfilling is an additional operation in the coal mining cycle that can reduce productivity and increase production costs. This thesis identifies the backfilling …
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Characterising the acid mine drainage potential of fine coal wastes
… mining history has led to a growing concern that coal-related AMD from these mines (both operational and defunct) will continue for centuries to come. Pyrite bearing fine waste, generated during coal preparation and beneficiation, is thought to carry a significant amount of AMD pollution risk. …
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Characterizing the potential environmental risks of South African coal processing wastes
The environmental impacts of coal processing wastes are a challenge in South Africa as large amounts of coal wastes are produced annually, pegged at 60 million tons per year according to Eberhard (2011). Whilst the fossil fuel-based industry is in decline globally, coal is likely to remain the …
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Bioaugmentation and biostimulation of a South African coal-based Technosol as a mine rehabilitation strategy
… over 70 million tonnes of material are added to coal waste dumps in South Africa. To alleviate the environmental and social burdens of unsightly mine waste dumps, improved management of existing discarded materials and new wastes, and fertile soils for land rehabilitation are essential. To …
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The Production of Low Ash Coals Using the Hydrophobic-Hydrophilic Separation Process with Novel Developments
… and contributes to a substantial amount of coal waste in impoundments. An impoundment is a dam built using coarse reject to hold fine reject in slurry. Because of the land-use and risk of an impoundment failure, these impoundments pose an environmental liability. To address ultrafine coal …
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Sediment dynamics on Wemyss beach, South Fife
… unusual mix of heterogeneous pebbles, sand and coal waste, and consequently provide a complex environment in which to examine sediment transport. The use of tracers revealed that low density coal pebbles were 'rejected' from the bedload layer of ironstone and sandstone pebbles, and were …
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Concentration and Recovery of Rare Earth Elements from Eastern US Coal Refuse
… by the US Department of energy have shown that coal and coal byproducts contain elevated contents of Rare Earth Elements (REEs), making them a potential resource for these critical materials. The approach employed in this research focused on the concentration and extraction of REEs from fine …
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Life cycle assessment of the production of xanthate salts and of their application for ARD mitigation
… flotation of sulphidic mine tailings and coal waste, with a view to mitigating acid rock drainage (ARD) risks through the pre-disposal removal of sulphide minerals. In South Africa, xanthate salts are produced by Senmin® International (Pty Ltd) via the conversion of carbon disulphide at …
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Acid biodesulphurisation of coal discards using a heap leaching approach
The extraction and processing of coal generate substantial amount of wastes, which include waste rock, coal discards, and coal fines, posing significant environmental risks. The presence of sulphidic minerals, particularly pyrite, in these wastes can lead to the formation of acidic runoffs, known …
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THE APPLICATION OF OXIDATIVE HYDROTHERMAL DISSOLUTION (OHD) TO ORGANIC-RICH SHALES
… effects of OHD on organic matter have focused on coal, coal waste, and biomass. This study explores the application of OHD to organic-rich shales, providing a baseline investigation into how highly aliphatic materials react under OHD conditions, what types of products are created during the …
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The Effects of Backfilling on Ground Control and Recovery in Thin-Seam Coal Mining
A large percentage of Southern Appalachian coal reserves are located in seams less than 36" thick. As thicker and currently more mineable, deposits are exhausted, methods of underground thin-seam extraction will have to be developed. These methods must be capable of removing coal efficiently and …
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LABORATORY AND FIELD INVESTIGATIONS OF COAL AND COAL PROCESSING WASTE - SIMULATION OF PRACTICES THAT MINIMIZE SULFATE AND CHLORIDE
The potential for mobilization of SO4 and Cl from coal stockpiles and coal processing waste and refuse (waste rock) disposal areas to the receiving streams and groundwater is an environmental concern and proper management practices are necessary to minimize the impact of these discharges. In an …
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NEW APPROACHES FOR MITIGATING ENVIRONMENTAL CONCERNS ASSOCIATED WITH COAL AND COAL COMBUSTION PRODUCTS
Currently, coal combustion plays an important role in meeting the energy needs of the United States. It is expected that the effective utilization of coal will be crucial for attaining energy independence for the nation in the next 25 to 30 years, if not longer. The United States burns about 20% of …
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CO2 sequestration using brine impacted fly fish
It was hypothesized that South African FA and brine could sequester CO2 through mineral carbonation. A statistical approach was undertaken to optimize the % CaCO3 formed from FA/brine/CO2 interaction with input parameters of temperature, pressure, particle size and solid/liquid ratio (S/L) being …