Thesis (M.A.)--Ohio University, August, 2005. / Title from PDF t.p. Includes bibliographical references (p. 100-108)

Thesis (Ph. D.)--Brigham Young University Dept. of Chemical Engineering, 2005. / Includes bibliographical references (p. 155-163).

Bibliography: leaves 279-293. Temperature-programmed Pyrolysis experiments employing Bowmans and Lochiel low-rank coal and treated Bowmans coals, were conducted to investigate the sulphur transformations during pyrolysis.

This thesis investigates the singing behaviour of coal tits (Parus ater) from two different study sites. A background to the functional significance of songs in a broad context is given in Chapter 1. This chapter also briefly introduces the biology of coal tits. Chapter 2 describes more general aspects of coal tit songs, and evaluates and compares the variability in song structure of two coal tit populations. The study has looked at the distribution of songs within populations, and at the effect of distance between individuals on the composition of their repertoires. The results are presented in Chapter 3. A new hypothesis has been proposed to explain the significance of song repertoires, namely the anti-exhaustion hypothesis. The hypothesis was tested on coal tits, and the results are presented in Chapter 4. Using playback experiments the singing interaction in coal tits was investigated. Two experiments were carried out in order to test the predictions that a bout of song could give information about individual's fitness, and that song length might indicate individual 'strength'. The results are presented in Chapter 5.

Amin Bagheri, for the Master of Science degree in MECHANICAL ENGINEERING AND ENERGY PROCESSES, presented on June 23, 2014, at Southern Illinois University Carbondale TITLE: STUDYING THE MAGNETIC SEPARATION OF OXYGEN CARRIER IN COAL DIRECT CHEMICAL LOOPING MAJOR PROFESSOR: Dr. Tomasz S. Wiltowski Magnetic separation of oxygen carrier from coal after combustion by-products was studied. Samples were prepared using iron metal, hematite and magnetite mixed with quartz in three different concentrations. A variable speed and magnetic field intensity separator unit was designed and constructed to prove the concept of magnetic separation. The unit went through trial and error steps to improve overall functionality and efficiency including belt material selection, electromagnet selection, feeder and collector buckets, drive drum and idler manufacturing. Prepared samples were tested in different velocities and magnetic field intensities.

Since a substantial amount of coal combustion byproducts (CCB) are produced each year, generating value-added product from fly ash, which is a major constituent of these CCBs, has been an important area of research for several decades. Natural magnetite (NM), which is used to maintain dense medium slurry pulp density in coal preparation plants, has a current market value of more than $200 per ton. The use of fly ash derived magnetite (FAM) as an alternative to natural magnetite has potential benefits for dense medium processes, such as lower cost, greater stability at low medium density, more efficient delivery systems. This study developed a suitable processing scheme to extract high-grade (> 96%) magnetite from fly ash generated from burning high sulfur coal, and investigated the suitability of the FAM product for dense medium application in coal preparation plants. A classifying cyclone was utilized in the process flow sheet for the pre-concentration of FAM in its underflow stream, which was enriched to high grade FAM by a single stage wet magnetic separator of low intensity (~1000 gauss). A statistically designed experimental program was utilized to maximize the magnetite grade and recovery achieved from the above mentioned flow sheet. The FAM product particles had a slightly coarser particle size distribution than the NM particles. In addition, the FAM particles were found to have a spherical shape; but about one unit lower specific gravity in comparison to the NM particles. However, the F5 Stability Index of the resulting FAM product was found to be in the desired range of 30 to 40 for its suitable application as a dense medium. The coal cleaning performance obtained from a 0.15 m diameter dense medium cyclone using dense medium prepared from both of FAM and NM, were quite similar. However, the effective separation density (SG50) obtained from the FAM-based dense medium was significantly different from the medium density; this may need further investigation in future. A preliminary economic analysis, conducted for a hypothetical mini-plant having a fly ash handling capacity of 100 ton/hour, indicated the cost of FAM extraction to be nearly $5/ton. The cost assumes that the FAM extraction plant is located at the fly ash producing utility site and does not include the cost of thermal drying that may be required to reduce the moisture content of the FAM filter cake produced at the FAM plant. A preliminary civil engineering study conducted to investigate the effect of FAM extraction on the compressive strength property of the non-magnetic flyash (left behind after FAM extraction) failed to produce a conclusive finding. The specimens prepared using 10% and 30% fly ash replacements indicated that the compressive strength does not change due to FAM extraction. However, the specimens using 20% fly ash replacement indicated that compressive strength does change due to FAM extraction. Hence, a more detailed study is recommended to investigate this discrepancy.

Large δ13C excursions present at the Permian-Triassic boundary are thought to indicate a considerable release of isotopically light carbon into the atmosphere (Retallack and Jahren, 2008). The largest of these excursions (-22.2 ‰) was measured in organic matter from Antarctica (Retallack and Jahren, 2008). Antarctic coals are known to be heavily intruded by Jurassic dikes and sills, and the δ13C values of the organic matter may have been influenced by later thermal alteration. In order to evaluate the influence of rank and maceral content on isotopic composition, a total of 335 samples described as Permian-age "coal" were obtained primarily from the United States Polar Rock Repository. Most of the organic matter from Permian coal seams in Antarctica has been extensively altered after burial by localized high heat flow and, in some cases, contact metamorphism associated with dikes and sills; this thermal alteration has likely changed the δ13C values of the organic matter. The rank of the samples prior to intrusion is estimated to be medium to high volatile bituminous. The majority of the samples analyzed (96%) have been altered to above low volatile bituminous rank based on vitrinite reflectance, most (83%) are semi- to meta-anthracites, and a few have been altered to anisotropic cokes. The samples do not follow the typical burial maturation geochemical track, as they are higher in volatile matter (%, daf) and O (%, dmmf), and lower in H (%, dmmf) than coals of the same rank that have undergone normal burial maturation. Carbon stable isotopic data indicate a weak correlation with coal rank as well as with the amount of pyrolitic carbon. Although the isotopically lightest samples measured in this study are located within what is interpreted to be the Permian-Triassic boundary, the effects of thermal alteration of organic matter on δ13C values must be considered in any interpretation of Permian-Triassic atmospheric conditions.

No description available.

M.Phil. ( Energy Studies) / Please refer to full text to view abstract

The use of magnetite as a medium in the wet processing of coal has been used since the early days of dense medium separation. The high magnetic susceptibility and density of magnetite make it an ideal medium to use in wet coal beneficiation because it is relatively easily and successfully recoverable. Owing to the need for more sustainable technologies, Coaltech has been investigating alternative dry processing processes: the Bohou process (developed in China) was identified as a possible feasible option. The Bohou process comprises dry dense medium separation using magnetite as the medium. The recovery and re-use of magnetite are, however, problematic. The aim of this investigation was to determine how efficiently magnetite can be recovered and to identify the factors influencing the magnetite losses during this dry processing. The test work for the project was divided into two phases. The aim of Phase 1 was to identify the magnetite losses to the oversize coal fraction for different moisture conditions of the coal and magnetite. In Phase 2, magnetite and high-titanium magnetite (an alternative source of magnetite) were used to conduct test work to determine which medium could be successfully recovered from fine coal. Magnetite or high-titanium magnetite was mixed with the coal sample as a medium. During Phase 2, the effects of using different screens and different moisture conditions were investigated. For both phases, the samples received were divided into three categories containing different moisture contents: dry coal and dry magnetite, dry coal with wet magnetite (4% to 4.4%), and wet coal (3.5% to 6.5%) with dry magnetite. In Phase 1, the coal samples were screened at 13.2 mm, the oversize mixed with magnetite, and then screened again with a 13.2 mm screen: the magnetite losses were then recorded. For Phase 2, the prepared samples were screened at 3 mm, 13.2 mm, and with a 3 mm high-frequency screen. The undersize was passed through a low-intensity magnetic separator. The recovered magnetite was then passed over a magna chute to recover additional magnetite. ii The results for both phases indicated that the highest recovery of magnetite occurred when dry magnetite and dry coal samples were used. The samples with wet magnetite also gave high recovery, but the samples with wet coal were detrimental to recovery and significant losses were observed. It was found that the magnetite stuck to the surface moisture of the coal. The use of a high-frequency screen improved recovery of the magnetite from the wet coal samples from 45.38% to 74.27%. Recovery from the high-frequency screen for both dry and wet magnetite samples was lower than that achieved with a conventional 3 mm screen. The test results indicated that magnetite can be recovered in the dry beneficiation of coal when the surface moistures of both the coal and magnetite are controlled. Use of a high-frequency screen can improve recoveries only for conditions where the surface moisture of the coal is high. / Dissertation (MSc (Metallurgy))--University of Pretoria, 2021. / CoalTech / Materials Science and Metallurgical Engineering / MSc (Metallurgy) / Unrestricted