The separation efficiency of a triboelectrostatic separation (TES) for fine coal cleaning depends profoundly on the surface charges of the particles involved. In general, the larger the difference between the charges of the particle to be separated, the higher the separation efficiency. The premise that coal and mineral matter can be triboelectrically charged differently serves as a basis for the TES process. In order to improve the separation performance, it is apparent that a highly efficient charger is needed for the TES unit, as well as the information on the triboelectrification mechanisms of the coal and mineral matter. Tribo- or contact electrification is a phenomenon in which electrical charge is usually transferred form one material to another, when two dissimilar materials are brought into rubbing or contact. In the present work, the triboelectrification mechanisms of coal, quartz, and pyrite were investigated in an in-line static mixer charger. A new in-situ charge-measuring device has been developed, in which an in-line mixer charger is located in side a Faraday cage. This makes it possible to observe the charging mechanisms of the particles when they pass through the mixer. This device was used to study the tribocharging mechanisms of coal, quartz, and pyrite as functions of the air velocity, particle feed rate, particle size, temperature, ash content, and the work functions of the materials that make up the in-line mixer. Evidence suggests that the charge transfer mechanisms of coal and mineral matter be due to electrons. A new turbocharger designed and developed in the present study has been tested and used to investigate the triboelectrification mechanisms of coal and quartz. The charge measurements were conducted using a developed on-line charge-measuring device, which is based on the principle of the Faraday cage. The tribocharging mechanisms of coal and quartz were investigated as functions of the particle feed rate, particle size, rotor-blade rotation speed, ash content, and the type of the materials used to construct the turbocharger. The information on the charging mechanisms of the coal and quartz will be useful for improving the triboelectrification process and subsequently the design of a TES unit. / Ph. D.

A thesis submitted to the Faculty of Engineering and Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy, Johannesburg 2017 / South Africa (SA) has an energy-intensive coal mining industry, where coal accounts for approximately 72% of total primary energy consumption in the country, particularly in the electricity sector, where 95% of total electricity generated is derived from coal. Pulverised coal combustion has been the preferred technology adopted for power generation in South Africa for many decades. These coal-fired power plants have no flue gas desulphurisation (FGD) equipment fitted at present. Therefore, these plants account for the majority of annual SO2, CO2, and NOx emissions, making them environmentally unsustainable for power generation. Such environmental issues add to the challenges for the power producer, who is required to meet not only energy demand, but also to compete with the export market for quality coals, and to ensure that electricity generation complies with ever-changing air quality standards. Circulating fluidised-bed combustion (CFBC), a technology for the combustion of coal, biomass, waste, has not been adequately explored or tested in South Africa previously. CFB combustion is currently under intense scrutiny amongst researchers evaluating its potential as an economic and environmentally acceptable technology, in particular for the burning of lowgrade coals. The main objective of this study is to undertake a case study using CFBC technology and to establish its potential for use in South Africa as a clean and cost-effective method in power generating for high-ash, low-grade coals. Experimental tests were conducted in a CFBC pilot plant in Finland, using two high ash coals, discarded coal from South Africa (SA) and a better quality coal from Russia for comparative purposes. A review was conducted of discard coals in South Africa in order to establish an inventory in support of their potential utilisation for power generation in circulating fluidised bed boilers. A further study established a comparison between pulverised coal (PC), and fluidised bed (FBC) technologies as a future benefit analysis. All four coals proved to have very high combustion efficiencies, despite significant quality differences in terms of petrographic composition and ash content. More specifically, the SA coals achieved combustion efficiencies of 99.6 %, 99.7 % and 99.8 %, where the Russian coal achieved 98.7 percent. The Russian coal was characterised as being low in ash and high in the reactive maceral vitrinite, the two South African coals possessed high ash content (35 to 45%), one with relatively high vitrinite, and the other very low vitrinite, whilst the South African discard possessed an ash content of 65-70% and extremely low reactive vitrinite content. All these factors lean towards the suitability of SA coals to the CFB technology. In terms of NOx emissions, all coals tested showed that their NOx and N2O emission meet the minimum requirements for small plants as set out by the European and SA standards, i.e. <300 ppm for a plant with generating capacity below 100 MW. This result is in agreement with data from the literature. The emission of SO2 depends on the sulphur content in the initial coal, which also has an impact on the Ca/S Ratio. SO2 emitted from the South African coals was higher than the national permitted standard, due to the low Ca/S ratio used. This was especially the case for South African discard. Vast reserves of discard coal containing from 2MJ/kg to 14 MJ/kg in calorific value have accumulated in South Africa since the last inventory of 2001, i.e. close to 1.5 billion tonnes are in existence. It is apparent that one of the looming challenges regarding discard coal is putting this ever-accumulating material to use. From the combustion results obtained in this research, it is proposed that such materials can be combusted in a CFBC boiler, and that it produces the same efficiency as other coals from South Africa and a clean coal from Europe. Ash distribution within the boiler was found to change in proportion of bed ash to fly ash, subject to the quality of the coal used. This is also likely to change the proportions of sulphur-absorbing sorbents in future. CO2 emissions from the coals under review were found to be very close, in the region of 12.8 to 13.8 percent. / XL2018

No description available.

This study concerns the people of the mining communities throughout the state of Illinois during the first three decades of the twentieth century. In the thirty-four years following the 1897 bituminous miners' strike and the subsequent 1898 event in Virden, the people of the Illinois mining communities developed a perspective and a standard of living that shaped their character. During these years, Illinois miners were thoroughly unionized and used the United Mine Workers of America (UMWA) as a vehicle to advance their lives and the lives of their families. Indeed, in 1923, the aging Mary Harris "Mother" Jones herself pointed to Illinois as "the best organized labor state in America" in her written request to be buried in the Mt. Olive, Illinois union cemetery. This perspective held by the people of the Illinois mining communities, herein labeled the "Illinois perspective," shaped every aspect of their lives including their values, economic decisions, and their union policies. Though the events for this perspective took hold following the 1897 strike, its roots go back farther in time to the Chartist movement in England. From these British immigrant beginnings and through the inclusion of new immigration from southern and eastern Europe at the turn of the century, Illinois miners and their families addressed the devastation of their industry and their way of life in ways that were fundamentally different than miners in other locales. When national union bureaucratization, as exemplified in the larger than life figure of John L. Lewis, threatened regional control and statewide decision making in the 1930s, many Illinois mining families abandoned the UMWA and created the Progressive Miners of America (PMA) in hopes of regaining regional control and weathering their extremely difficult present. Current scholarship regarding Illinois miners from this era generally focuses on specific regions within the state or on the "Illinois Mine Wars" of the 1930s when members of the badly fractured mining district fought with, and sometimes killed, one another. This study brings the state of Illinois together as one united district during its time frame of concentration and argues all regions of the state shared this united perspective. Various primary sources, oral histories, contemporary newspaper accounts, and a statistical analysis of the 1908 Macoupin County Coal Miners' Application Book help to explain how these people lived their lives and why it was possible for them to do so.

The mitigation of greenhouse gas emissions and enhanced recovery of coalbed methane are benefits to sequestering carbon dioxide in coal seams. This is possible because of the affinity of coal to preferentially adsorb carbon dioxide over methane. Coalbed methane is the most significant natural gas reserve in central Appalachia and currently is economically produced in many fields in the Basin. This thesis documents research that assesses the capacity of coal seams in the Central Appalachian Basin to store carbon dioxide and verifies the assessment through a field validation test. This research allowed for the first detailed assessment of the capacity for coal seams in the Central Appalachian Basin to store carbon dioxide and enhance coalbed methane recovery. This assessment indicates that more than 1.3 billion tons of carbon dioxide can be sequestered, while increasing coalbed methane reserves by as much as 2.5 trillion cubic feet. As many of the coalbed methane fields are approaching maturity, carbon sequestration and enhanced coalbed methane recovery has the potential to add significant recoverable reserves and extend the life of these fields. As part of this research, one thousand tons of carbon dioxide was successfully injected into a coalbed methane well in Russell County, Virginia as the first carbon dioxide injection test in the Appalachian coalfields. Research from the field validation test identified important injection parameters and vital monitoring technologies that will be applicable to commercial-scale deployment. Results from the injection test and subsequently returning the well to production, confirm that fractured coal seams have the potential to sequester carbon dioxide and increase methane production. It was demonstrated through the use of perfluorocarbon tracers that there is a connection through the coal matrix between the injection well and surrounding producing gas wells. This connection is a cause for concern because it is a path for the carbon dioxide to migrate to the producing wells. The thesis concludes by presenting options for mitigating carbon dioxide breakthrough in commercial-scale injection projects. / Ph. D.

The 1990 Clean Air Act Amendment (CAAA) contains provisions that will establish new emission standards for 190 potentially hazardous air pollutant precursors (HAPPs). Studies have suggested that many of these HAPPs have the potential to be removed prior to combustion. This thesis details the findings of a bench-scale test program that was implemented to evaluate the capabilities of physical coal cleaning technologies on the removal of trace elements from coal. Test work was completed on Pittsburgh No. 8 seam coal that was processed using physical cleaning techniques (i.e., crushing, dense media separation, froth flotation, and enhanced gravity separation). The bench-scale test circuit incorporated crushing and rewashing a coarse, mid-density product with hopes that trace element rejections would improve due to greater liberation of HAPPs. The results of this investigation showed that trace elements were predominately rejected in the coarse coal portions of the processing circuit (i.e., dense media separation), and only slight improvements in rejections could be realized from crushing any portion of the coal. It was also shown that trace element rejection could be incrementally increased with minimal loss of total yield or combustible recovery when froth flotation is put in series with enhanced gravity separation. The results of the bench-scale test work, along with trace element float-sink and release analysis data, were used to develop a simulator that can predict trace element rejections from any coal processing circuit. This was achieved by applying general partition functions to trace element washability and bench-scale processing data. Simulation studies included comparing three physical coal cleaning techniques. The results of these analyses showed that although no net improvement in trace element rejection can be gained through crushing the circuit feed, there is a slight increase in product yield. Crushing a mid-density coarse coal product also showed little or no improvement in trace element rejection. / Master of Science

“Mining Interruption” tackles the question of how to make sense of disaster by exploring the Soma mine disaster. On May 13, 2014, an explosion in the Eynez underground lignite coal mine caused a fire that blocked the exit, sealing in 301 mineworkers who died of carbon monoxide poisoning in the town of Soma, in the city of Manisa, in Aegean Turkey. While the European Union was becoming relatively greener next door, coal extraction had begun to increase in Turkey after the Justice and Development Party [Adalet ve Kalkınma Partisi] came to power in early 2000s. The relative decline of coal in the Global North paved the way for increased amounts of internal coal extraction and consumption in the energy geographies of the Global South and other non-Western countries as well as of Indigenous lands. The shift created biopolitically, socially, and technologically renewed forms of exploitation of labor, bodies, and nature, which contextualize the Soma mine disaster. Based on 18 months of ethnographic fieldwork and 68 open-ended interviews conducted in the Soma Coal Basin, this dissertation presents one constellation of the disaster by exploring four figures—The Accidented, the Bride, the Deserving, and the Striker—both as effects and as ongoing temporalities of the disaster. It contributes to critical disaster studies by defining and studying disaster not as a category of event, but as a concept through which multiple temporalities, lived experiences, and knowledges hang together. This loose definition of disaster is complemented by a reinterpretation of Walter Benjamin’s take on one of Bertolt Brecht’s most important dramaturgical techniques: interruption. In the dissertation, interruption is re-conceptualized as an experiential (hence temporal) concept that captures out-of-the-ordinary moments or flashes that interrupt everyday life in a way that permits a reevaluation of historical-material conditions. Interruptions are openings through which people may or may not follow an accidental course of action in order to overcome, better deal with, or politically respond to their conditions. The multiplicity of interruptions that are integral to the ongoing Soma mine disaster intersect with labor, fossil fuel production and its toxic effects, disability/debility, gendered oppression, disaster management, and social assistance. Some of these interruptions are experienced as rupturing events while others are perceived below the threshold of the event as such—as noneventful or not-so-eventful sensibilities, intensities and material changes. Each figure in question is a constellation in itself, a web of interdependencies, ruptures and materialities formed among human beings, state actors, coal, land, tobacco and other plants, limbs, organs, and names. In “The Accidented,” by examining mineworkers’ experiences and the terminology of becoming accidented (a direct translation of the term kazalanmak [in infinitive form]) through work accidents, the dissertation presents a critique both of existing disability assessment techniques and processes, and of understandings of disability as identity, which peripheralize labor-related and other experiences of (dis)ability and debility. In “The Bride,” by surveying the pervasive rumors about the widows of the 301 mineworkers, and their naming by the townspeople as “the brides,” the dissertation studies the differential treatment of the families of the 301 and the rest of the mining community through the state’s twofold disaster management strategy, and the ways in which people deal with this treatment through gossip, resentment, and kinship ties. In so doing, the dissertation also explores how affinal kinship relations have been transformed in the region due to the rise of coal mining, which coincides with the heightened neoliberalization of agriculture. In “The Deserving,” by investigating the materiality and movement of the lignite coal that is known as “Soma coal,” the dissertation articulates the ways in which the lives and desires of working-class and peasant communities have been reshaped through coercion, patronage, ideological interpellation, and the subjectivizing effects of Soma coal. It presents Soma coal as a pedagogical infrastructure that has emerged through the materiality of coal, and the regimes and networks of labor and welfare provision in contemporary Turkey. Finally, through the figure of “The Striker,” the dissertation examines the three-year long compensation struggle and protests of Soma and Ermenek mineworkers (2019–2021) as a set of emergency strikes that interrupted various processes, technologies, social networks, and modes of life that are formally and/or really subsumed within capital. The concept of “emergency strike” is used in order to encapsulate a form of strike that emerges with whatever means available in a given context, and as a collective act of seizing perceived last chances. This discussion builds on a recent wave of theorization concerning forms of unconventional strike that aim to disarticulate mechanisms and processes of real subsumption and/or state sovereignty. The dissertation shows how mineworkers organized against the backdrop of the Soma mine disaster. In doing so, it demonstrates how mineworkers re-exceptionalized their living and working conditions under a state of exception that has become the rule in Turkey since the 2016 coup attempt while it had already become the rule in the Soma Basin after May 13, 2014.

The object of this investigation was to determine whether or not a certain sample of raw resin, collected by Mr. Adriaan Nagelvoort from coal from Huntington Canyon, Emery County, Utah, could be separated into more than one fraction with each fraction having distinctly different properties. Three methods of separation were attempted: (l) Separation of specific gravity fractions, (2) separation by use of solvents, and (3) chromatographic separation. Properties determined as a means of establishing any differences in the resins were: solubility, softening points, acid numbers, and iodine numbers.

No description available.

No description available.