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Beneficiated coals' char morphology
Morfología de carbonizados de carbones beneficiados
Keywords:
morphology, char, devolatilisation, beneficiation, image analysis. (en)caracterización morfológica, carbonizados, desvolatilización, beneficio, análisis de imagen. (es)
This work evaluated the char morphology of beneficiated and original coal (without beneficiation) from four Colombian coalmines: Cerrejón (La Guajira), La Jagua (Cesar), Guachinte (Valle del Cauca) and Nechí (Antioquia). Column flotation was used to obtain beneficiated coal, whereas a drop tube reactor at 1,000oC, 104 oC/s heating rate and 100 ms residence time was used to obtain char. The chars were analysed by image analysis which determined their shape, size, porosity and wall thickness. It was found that char morphology depended on coal rank and maceral composition. Morphological characteristics like high porosity, thinner walls and network-like morphology which are beneficial in improving combustion were present in vitrinite- and liptinite-rich lowest-ranking coals. Beneficiated coals showed that their chars had better performance regarding their morphological characteristics than their original coal chars.
Este trabajo evaluó la morfología de carbonizados beneficiados y sin beneficiar (originales) de cuatro carbones colombianos: El Cerrejón (Guajira), La Jagua (Cesar), Guachinte (Valle) y Nechí (Antioquia). Los carbones beneficiados se obtuvieron usando un proceso de flotación en columna, mientras que los carbonizados, en un reactor tubular de caída a 1000 oC, con una velocidad de calentamiento de 104 oC/s y un tiempo de residencia de 100 ms. Los carbonizados se analizaron usando análisis de imagen, con la cual se determinó su forma, tamaño, porosidad y espesor de pared. Se encontró que la morfología de los carbonizados depende del rango del carbón y de su composición maceral. Características morfológicas tales como alta porosidad, menor espesor de pared y morfología tipo red, adecuadas para una mejor combustión, se encontraron en los carbones de menor rango y ricos en vitrinita y liptinita. Se halló que los carbonizados de carbones beneficiados poseen mejores características morfológicas en comparación con los carbonizados de carbones originales.
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Copyright (c) 2013 Diana Vargas, Deisy Chaves Sanchez, Maria Patricia Trujillo Uribe, Jorge Luis Piñeres Mendoza, Juan Manuel Barraza Burgos
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