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Kronbauer M.A.,Centro Universitario La Salle Mestrado Em Avaliacao Of Impactos Ambientais Em Mineracao | Kronbauer M.A.,Federal University of Rio Grande do Sul | Izquierdo M.,Cranfield University | Dai S.,China University of Mining and Technology | And 9 more authors.
Science of the Total Environment | Year: 2013

The nano-mineralogy, petrology, and chemistry of coal gasification products have not been studied as extensively as the products of the more widely used pulverized-coal combustion. The solid residues from the gasification of a low- to medium-sulfur, inertinite-rich, volatile A bituminous coal, and a high sulfur, vitrinite-rich, volatile C bituminous coal were investigated. Multifaceted chemical characterization by XRD, Raman spectroscopy, petrology, FE-SEM/EDS, and HR-TEM/SEAD/FFT/EDS provided an in-depth understanding of coal gasification ash-forming processes. The petrology of the residues generally reflected the rank and maceral composition of the feed coals, with the higher rank, high-inertinite coal having anisotropic carbons and inertinite in the residue, and the lower rank coal-derived residue containing isotropic carbons. The feed coal chemistry determines the mineralogy of the non-glass, non-carbon portions of the residues, with the proportions of CaCO3 versus Al2O3 determining the tendency towards the neoformation of anorthite versus mullite, respectively. Electron beam studies showed the presence of a number of potentially hazardous elements in nanoparticles. Some of the neoformed ultra-fine/nano-minerals found in the coal ashes are the same as those commonly associated with oxidation/transformation of sulfides and sulfates. © 2013 Elsevier B.V..

Hower J.C.,University of Kentucky | O'Keefe J.M.K.,Morehead State University | Henke K.R.,University of Kentucky | Wagner N.J.,University of Witwatersrand | And 7 more authors.
International Journal of Coal Geology | Year: 2013

The Truman Shepherd coal mine fire, Floyd and Knott counties, Kentucky, has been the subject of several field investigations over the last four years. During July and November 2011 and January 2012 field investigations, we measured gas emissions, collected minerals, and characterized the nature of the fire. New vents opened over the course of the study and have continued to open since January 2012, coincident with the eastward advance of the fire. This is the first study of Kentucky coal fires where the original vents were able to be studied in addition to new vents on each subsequent trip. Neoformed minerals associated with the vents are primarily ammonium sulfates and ammonium chlorides with minor zeolites. BTEX emissions, especially benzene, vary considerably, ranging from relatively low to comparable to those from very large fires, such as the Ankney coal fire in Wyoming. Vent emission data collected displays a general trend of decreasing carbon dioxide and carbon monoxide emissions from July through January. The projected annual greenhouse gas and mercury emissions from the fire are 65.69t of CO2, 4.51t of CO, 5.73t of CH4, and 1.667kg Hg. The November 2011 CO/CO2 ratios are indicative of more complete combustion than at any other time during the study, possibly indicative of decreased moisture in the system. © 2013 Elsevier B.V.

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