Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 21, 2007) Includes bibliographical references.

[pt] Este estudo apresenta a caracterização de dois tipos de cinzas (de fundo e volante) obtidas da queima de carvão mineral em usinas termelétricas, tendo como objetivo avaliar sua aplicabilidade em camadas de base de pavimentos rodoviários, através da mistura destas cinzas a um solo areno-siltoso não-laterítico característico do estado do Rio de Janeiro. Foram realizados ensaios de caracterização física (granulometria e limites de Atterberg), química (fluorescência de raio-X por energia dispersiva), mecânica (compactação, módulo de resiliência e deformação permanente) e, por se tratar da utilização de resíduos industriais, ensaios ambientais de solubilização e lixiviação. Tais ensaios foram realizados para o solo puro e para as misturas de solo-cinza de fundo (30 e 40 por cento de cinzas de fundo) e solo-cinza volante (10 e 20 por cento de cinza volante), sendo estes teores relacionados ao peso do solo seco. Também foram ensaiados corpos de provas com a adição de 3 por cento cal. Baseando-se nos dados resultantes dos ensaios mecânicos foi realizado o dimensionamento mecanístico-empírico para uma estrutura típica de pavimento. As misturas com inserção de cinzas apresentaram um comportamento mecânico compatível com as exigências de um pavimento de baixo volume de tráfego. Os resultados obtidos demonstram que o solo em estudo é dependente da tensão confinante e que a inserção de cinza volante e a cura prévia aumentam consideravelmente o valor do módulo de resiliência, o que resulta na diminuição da espessura da camada de base em comparação ao solo puro, para um mesmo nível de carregamento e mesmos critérios de dimensionamento. Os resultados com as cinzas de fundo também apresentaram resultados satisfatórios, aumentando o valor do módulo de resiliência, apesar de em menores taxas do que as cinzas volantes, no caso das misturas com a presença de cal e, contudo, nas misturas sem a adição de cal, obtendo melhores resultados ao serem comparados com as misturas com a presença das cinzas volantes. Os resultados obtidos foram satisfatórios, sendo dependentes do teor e do tipo de cinza utilizado, da presença da cal, além do tempo de cura. Tais fatos, juntamente com os resultados dos ensaios ambientais ressaltam o emprego positivo de ambos os tipos de cinzas (de fundo e volante) de carvão mineral para aplicação em camadas de base de pavimentos rodoviários, minimizando problemas atuais de disposição de resíduos em lixões e aterros sanitários, dando um fim mais nobre a este material. / [en] The research consists in examining the applicability of two kinds of ash (fly and bottom) of coal combustion residue from thermal power, on the layers of pavements base road by mixing these ashes with a nonlateritic sandy-silty soil, characteristic of the Rio de Janeiro state, with and without lime addiction. This study presents the results of physical characterization (granulometry and Atterberg limits), chemistry (fluorescence X-ray energy dispersive), and mechanics (compression, resilient modulus and permanent deformation), and considering that ashes are industrial waste, environmental testing solubilization and leaching. These tests were conducted on the pure soil, on the ashes and on soil with bottom ash (30 and 40 per cent of bottom ash) and fly ash (10 and 20 per cent of fly ashes) mixtures, these levels of ashes are related to the weight of dry soil, with and without lime addiction. The composite model for resilient modulus were obtained, which represents the mechanical behavior, using the finite element program (SisPAV) for the pavement design. The mixtures with the addiction of ashes showed a mechanical behavior consistent with the requirements for low traffic roads. The results show that the soil is dependent on confining pressure and the inclusion of fly ash and the mixture cure dramatically increase the value of resilient modulus, which is revealed by thinner base layer in comparison to the pure soil, for the same load level and the same design criteria. The results of bottom ashes also were aceptable, increasing the value of resilient modulus in lower taxes than the fly ashes with the addiction of lime, but showing better results in the mixtures without addiction of lime, when comparing wiht the mixtures with fly ashes. The results were satisfactory, and dependents of the levels and kind of ashes, of addiction of lime, and the cure, highlighting the use of both ashes of mineral coal in pavement base roads, eliminating the current problems of waste disposal in dumps and landfills, putting a best end for this material.

SAMPAIO, K. N. H. Avaliação técnica da utilização de cinzas de combustão do carvão mineral provenientes de termelétrica em argamassas de revestimento. 2017. 89 f. Dissertação (Mestrado em Engenharia Civil)-Centro de Tecnologia, Programa de Pós-Graduação em Engenharia Civil: Estruturas e Construção Civil, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Hohana Sanders (hohanasanders@hotmail.com) on 2017-10-24T14:13:48Z No. of bitstreams: 1 2017_dis_knhsampaio.pdf: 2174900 bytes, checksum: 3f9554b5853871212621dd3af72085ff (MD5) / Approved for entry into archive by Marlene Sousa (mmarlene@ufc.br) on 2017-11-07T18:47:19Z (GMT) No. of bitstreams: 1 2017_dis_knhsampaio.pdf: 2174900 bytes, checksum: 3f9554b5853871212621dd3af72085ff (MD5) / Made available in DSpace on 2017-11-07T18:47:19Z (GMT). No. of bitstreams: 1 2017_dis_knhsampaio.pdf: 2174900 bytes, checksum: 3f9554b5853871212621dd3af72085ff (MD5) Previous issue date: 2017-06-14 / In Brazil, 65% of the power generation projects are thermal plants. In the state of Ceará they are responsible for 61.11% of the energy production, highlighting the thermal plants of Pecém I and Pecém II which together have an installed capacity of 1085MW. However, the thermal plants have a major environmental liability for its waste generation, among which stands out the ashes from the combustion of coal (ACC). In order to give a more suitable destination to this waste, its incorporation into raw materials may generate sustainable materials. This thesis proposes to apply those thermal plants’ ashes in mixed mortar of cement and lime, replacing lime by ACC in contents of 0%, 25%, 50%, 75% and 100%, analyzing the characteristics in fresh state and hardened states, as well as its durability. Regarding the fresh state’s tests, the consistency index was fixed and it was quantified the amount of water necessary for each mixture to reach it. Afterwards, the loss of consistency of each mortar was evaluated after five and ten minutes. Finally, the rheology was investigated by the Squeeze-flow method. Regarding the hardened state’s tests, the tensile strength in flexion, the compressive strength and the tensile strength were evaluated. In the end, the durability was analyzed through the permeability test by the pipe method and the cracking aperture lengths. The results were analyzed by an analysis of variance (ANOVA) and the multiple comparisons of means by the Duncan’s test, using the software Statistica 7.0. They indicate that its replacement is technically feasible, as giving a better performance in its workability, resistance and durability. All of the mortars with ACC have shown an improvement in its characteristics compared to the reference mortar, and the mortars with more than 75% of ACC stood out among in resistance, in consistency, and in durability. Keywords: Coal Ash. Sustainable Materials. / No Brasil, 65% dos empreendimentos de geração de energia são usinas termelétricas. No Ceará as mesmas são responsáveis por 61,11% da produção de energia do estado, destacando-se as usinas termelétricas de Pecém I e Pecém II, que juntas possuem a capacidade instalada de 1085MW. Contudo, as usinas termelétricas possuem um grande passivo ambiental pela sua geração de resíduos, dentre os quais se destacam as cinzas da combustão do carvão mineral (CCCM). Para dar uma destinação adequada a esse resíduo, busca-se incorporá-lo em matérias-primas. O presente trabalho propõe aplicar essas cinzas na confecção de argamassas mistas de cimento e cal, substituindo a cal por CCCM nos teores de 0%, 25%, 50%, 75% e 100%, analisando assim suas características tanto no estado fresco quanto no estado endurecido. Com relação aos ensaios no estado fresco, foi fixado o índice de consistência e a partir do mesmo foi quantificada a quantidade de água necessária para cada mistura atingi-lo, em seguida foi avaliada a perda de consistência da argamassa após cinco e dez minutos. Por fim, foi investigada a reologia pelo método do Squeeze-flow. Com relação aos ensaios no estado endurecido, foram avaliadas as resistências à tração na flexão e à compressão e a resistência de aderência à tração. Finalmente, a durabilidade foi analisada através dos ensaios de permeabilidade pelo método do cachimbo e a taxa de abertura de fissuras. Os resultados foram analisados por uma análise de variância (ANOVA) e o comparativo múltiplo de médias pelo teste de Duncan, utilizando o software Statistica 7.0. Os mesmos indicaram que a substituição é viável tecnicamente conferindo um melhor desempenho na sua trabalhabilidade, resistência mecânica e durabilidade. Todas as argamassas com CCCM mostraram melhoras em suas características quando comparadas ao traço de referência, sendo a argamassa com teores acima de 75% de CCCM as que mais se destacaram em resistência, consistência e durabilidade.

M.Sc. / The study site for this project is New Clydesdale Colliery situated in the Witbank Coalfield, South Africa. The Witbank Coalfield is located within the northern part of the Karoo Basin where the major coal deposits in South Africa are located. Optimum ash fusion temperatures derived from coal in this region are approximately 1400°C, and higher, although temperatures above 1300°C are also acceptable. In certain coal seams the ash fusion temperatures drop well below this optimum temperature, leading at times to problems in the user industry. Ash fusion temperature which is the temperature at which the mineral matter in coal begins to soften, flow and fuse, is an important aspect relating to coal utilization but is little understood and under-studied in South Africa. The objective of this thesis is to attempt to determine what factors, mineralogical or inorganic chemical, influence variations in the ash fusion temperatures in certain coal samples. An understanding of this problem will have a bearing on the ultimate assessment of a coal for utilization purposes, in general, and ash deposition prediction in future boiler plants in particular. This study is somewhat pioneering as no detailed studies have been undertaken or published previously. Samples were collected at four sites from New Clydesdale Colliery. The sample sites were selected based on pre-existing knowledge of the ash fusion temperatures obtained from company analytical sheets. The sites were therefore representative of low and high ash fusion temperature coal. The first two sites were located in the opencast area where the No. 2 seam is actively being mined. The other two sites were located underground where mining has ceased. Conventional analyses conducted on the samples include proximate analyses, calorific values, percentage sulphur, and ash fusion temperatures. Further analyses performed included ash analyses (composition of ash), X-ray diffraction, scanning electron microscopy and petrographic studies. It was found that although complex relationships exist between ash fusion temperature and the various geological and coal parameters, positive results were obtained. These indicate a possible relationship between low ash fusion temperatures and i) finer size fractions, ii) an increase in iron content present in the form of pyrite and iii) the form in which pyrite is present, namely cleats. High ash fusion temperatures tend to correlate with i) the absence of pyrite or ii) pyrite present as framboids.

In February 2014, a coal ash spill on Duke Energy's Dan River Plant in Eden, NC released approximately 39,000 tons of coal ash into the Dan River. It took approximately one week to stop the spill. Starting in February 2015, drinking water utilities using the Dan River experienced a series of taste and odor (TandO) events described as "earthy" or "musty". Similar TandO events were not documented before the coal ash spill. This research attempted to understand causes of the TandO events and if the coal ash spill was connected. A variety of water quality analyses were performed on twelve sites from August 2016 to September 2017 on the Dan and Smith Rivers. The Smith River served as the control. From concentrations of coal ash indicators (particularly Ba, Sr, As, V, and Br-), there was a signature of coal ash on the Dan River that was not present on the Smith River. The signature could not be attributed to the coal ash spill, as the signature was present upstream of the spill. Chronic ecosystem toxicity due to metals was low and not significantly different between the Dan and Smith Rivers. No substantial TandO events occurred during the period of this study. All monitored odorants were detected with varying frequencies in both the Dan and Smith Rivers. No significant change in odorant concentration was found above and below the location of the coal ash spill. / MS

No description available.

In recent years, communities that source raw water from the Dan River experienced two severe and unprecedented outbreaks of unpleasant tastes and odors in their drinking water. During both TandO events strong 'earthy', 'musty' odors were reported, but the source was not identified. The first TandO event began in early February, 2015 and coincided with an algal bloom in the Dan River. The algal bloom was thought to be the cause, but after the bloom dissipated, odors persisted until May 2015. The second TandO in October, 2015 did not coincide with observed algal blooms. On February 2, 2014 approximately 39,000 tons of coal ash from a Duke Energy coal ash pond was spilled into the Dan River near Eden, NC. As there were no documented TandO events before the spill, there is concern the coal ash adversely impacted water quality and biological communities in the Dan River leading to the TandO events. In addition to the coal ash spill, years of industrial and agricultural activity in the Dan River area may have contributed to the TandO events. The purpose of this research was to elucidate causes of the two TandO events and provide guidance to prevent future problems. Monthly water samples were collected from August, 2016 to September, 2017 from twelve sites along the Dan and Smith Rivers. Multivariate analyses were applied to look for underlying factors, spatial or temporal trends in the data. There were no reported TandO events during the project but sensory analysis, Flavor Profile Analysis, characterized earthy/musty odors present. No temporal or spatial trends of odors were observed. Seven earthy/musty odorants commonly associated with TandO events were detected. Odor intensity was mainly driven by geosmin, but no relationship between strong odors and odorants was observed. / Master of Science

Highly acidic and metal-rich runoff from coal storage facilities can have a dramatic impact on local surface and ground water quality. In order to identify important reactions governing metal transport within subsurface environments subject to infiltration of coal pile runoff, samples of uncontaminated subsoil and aquifer materials adjacent to the D-Area coal stockpile runoff containment basin at the Department of Energy's Savannah River Site were collected and subjected to leaching with the acidic, metalliferous coal pile runoff. Columns were packed to bulk densities of 1.5 Mg m³ and subjected to steady, saturated flows of 0.2 and 1.3 cm h⁻¹, Effluent was collected and multicomponent transport through the subsoil and aquifer materials evaluated. Observed transport was then related to soil chemical and mineralogical properties. Mass balance calculations, a sequential dissolution scheme in which column leaching was terminated and elements partitioned to aqueous, <i>M</i> NH₄CI, and ammonium oxalate in the dark (Ox)-extractable phases, and mineralogical and surface chemical analyses were used to identify important chemical processes and mineralogical alterations. / Ph. D.

Millions of tons of ash and slag are produced each year as a result of energy production. This study looks at the mineralogy and textures in the ash resulting from the gasification of a 25% Passaic Valley sewage sludge, 75% Pittsburgh #8 coal slurry in a Texaco gasification facility and at ash resulting from the incineration of municipal solid waste at several facilities in Virginia and North Carolina. This information is then compared with similar studies done on ash and slag from coal-burning power plants and a study done on petroleum coke slag which was produced at a Texaco gasification facility. Lastly, a comparison of bulk chemistries of ashes to those of soil and crustal rocks is made. A general understanding of the stability of elements, especially metals, in terms of the phases in which they are contained as well as the textures, was hoped to be gained from this study. Samples for this study were polished sections which were 2.54 em in diameter that were set in cold-setting epoxy then ground and polished. Samples were then studied under a reflected light microscope before being carbon coated for study on a SEM and an electron microprobe. Photos of textures and analyses were made throughout. At least 50% of the ash from all sources was a Si-Al oxide rich glass which had varying amounts of Fe, Ca, K, P, Mg, and Ti and other trace elements. Fe oxides and spinels were common phases found. Pb and Zn were rarely encountered, but were found as both oxides and sulfides. Cr was found in the form of spinels, often covered by a protective AI enriched outer rim. The heavy metals found were successfully bound as mineral analogs or as a glass phase. The only phase found to be reactive was an AIC matrix containing subhedral SiC crystals. The AI phase effervesced when placed in contact with water, changing from tan to greenlblue/violet in color, releasing a gas (probably CO₂, C2H2, or CH4) in the process. / Master of Science

A dissertation submitted to the Faculty of Engineering, University of Witwatersrand, in fulfillment of the requirements for the degree of Master Science in Engineering / The Electricity Supply Commission of South Africa (Eskom) have identified open cast coal mine backfill areas as potential disposal sites for the large volumes of coal ash produced by their power stations. As Eskom's power stations are mainly situated in agricultural and coal rich areas of the provinces of Mpumalanga and the Free State, the sterilisation of substantial areas of agricultural soil and coal deposits is thus reduced. The construction of a tailings dam or dump on uncompacted open cast mine backfill creates various problems related to the settlement of the backfill. The scale of the operation, the large particle size and heterogeneous nature of the backfill and its method of placement complicates the prediction for settlement of the backfill. Areas in excess of 74 000 ha could be subjected to opencast mining in Mpumalanga and for future development of these areas more information regarding the magnitude and mechanics of mine backfill settlement is required. This dissertation describes two large scale field tests in which the settlement of mine backfiil was studied during the construction of a test section of an ash tailings dam and the construction of a dry ash dump. / Andrew Chakane 2019