Petrographic characterization of coals as a tool to detect spontaneous combustion potential

Claudio Avila, Tao Wu, Edward Lester

    Research output: Journal PublicationArticlepeer-review

    45 Citations (Scopus)

    Abstract

    Textural features of 25 worldwide coals were studied after slow oxidation processing (0.5 C min-1 from 20 to 250 C in air) using oil immersion microscopy and image analysis techniques. The characterization of samples, before and after oxidation, showed important changes in vitrinite reflectance with high reactive coals, which also related to their intrinsic self-oxidation potential. The morphology of the coal particles was also altered after the oxidation, to produce at least six different morphotypes. Particles with 'homogeneous change of reflectance' and particles with 'oxidation rims' were predominant in the samples studied, which related to boundary reactive conditions (kinetic and diffusion control of the reaction respectively). These textural characteristics indicate how particles interacted with oxygen at low temperatures, which could be used to predict the most probable pathway during the early stages of oxidation which could then lead to a spontaneous combustion event. The magnitude of the reflectance change and the morphological characteristics of samples studied were also related to the reactivity properties, providing an additional source of information to identify coals prone to spontaneous combustion.

    Original languageEnglish
    Pages (from-to)173-182
    Number of pages10
    JournalFuel
    Volume125
    DOIs
    Publication statusPublished - 1 Jun 2014

    Keywords

    • Coal
    • Image analysis
    • Self-heating
    • Self-oxidation
    • Spontaneous combustion

    ASJC Scopus subject areas

    • Chemical Engineering (all)
    • Fuel Technology
    • Energy Engineering and Power Technology
    • Organic Chemistry

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