title: Effective removal of sulfur components from Brazilian power-coals by ultrasonication (40kHz) in presence of H2O2.
abstract: The present investigation reports a preliminary attempt of using ultrasonic energy (40kHz) to clean some low rank high sulfur Brazilian power-coal samples in presence of H2O2 solution. All types of sulfur components (i.e. pyritic, sulfate and organic) could be removed from the coal samples by this process. The raw and ultrasonicated coal samples were characterized by chemical analysis, Fourier Transformation Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), focused ion beam (FIB), high-resolution transmission electron microscope (HR-TEM) with selected area electron diffraction (SAED) and/or microbeam diffraction (MBD), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectrometer (EDS), and Thermogravimetry (TG-DTG) techniques to evaluate the clean-coal quality. The FT-IR spectroscopic analysis demonstrated the formation of oxidized sulfur species (SO and -SO2) and their subsequent removals after ultrasonication. The XRD profiles supported the presence of mineral matters in the coals. The TG-DTG profiles of the beneficiated coals revealed their improved quality for using in thermal plants with better combustion efficiency.
authors.affiliation: Coal Chemistry Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, India. Electronic address: bksaikia@gmail.com.
authors.forename: Binoy K
authors.initials: BK
authors.lastname: Saikia
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors.forename: Adilson C
authors.initials: AC
authors.lastname: Dalmora
authors.affiliation: Coal Chemistry Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, India.
authors.forename: Rahul
authors.initials: R
authors.lastname: Choudhury
authors.affiliation: Coal Chemistry Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, India.
authors.forename: Tonkeswar
authors.initials: T
authors.lastname: Das
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors.forename: Silvio R
authors.initials: SR
authors.lastname: Taffarel
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil. Electronic address: felipeqma@hotmail.com.
authors.forename: Luis F O
authors.initials: LFO
authors.lastname: Silva
keywords: Brazil power-coal; Coal beneficiation; Coal characterization; Desulfurization of coal; High sulfur coals; Ultrasonication of coal