Characterization of Upgraded Brown Coal (Ubc)

Umar, Datin Fatia; Daulay, Bukin; Usui, Hiromoto; Deguchi, Takao; Sugita, Satoru

doi:10.1080/07349340590927350

Cited by 29 publications

(1 citation statement)

References 7 publications

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“…13 Other values include a low-rank Bulianta 159 °C66 and a subbituminous coal 146 °C. 67 However, the spontaneous combustion of coal is complex and dynamic. 46,68 Thus, a singular technique is unlikely to capture spontaneous combustion behavior occurring at exposed coals.…”

Section: Resultsmentioning

confidence: 99%

Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State¹³C NMR, LDIMS, and HRTEM

Zhang

Zhong

et al. 2019

Energy Fuels

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China has a considerable lignite deposit in the Xinjiang province, but surface and underground coal seam fires pose a threat to the resources, environment, economy, and health. As the chemical and physical structure impacts coal fire propensity and behavior, two raw Xinjiang lignites were examined from the Shaerhu (SEH) and Piliqing (PLQ) Collieries. The SEH lignite is more prone to spontaneous combustion (from regional observations). These coals were of the same geological age and were both inertinite-rich 69.8 and 95.6% for SEH and PLQ, respectively (by the point counting approach). The more spontaneous combustion prone lignite had a significantly higher micropore contribution and surface area (92.4% and 195.6 m2/g), while both coals had similar micro- and mesopore size distribution ranges. Despite being classified as lignite by the mean vitrinite random reflectance (R r, 0.30 and 0.26%) the inertinite contribution displaces some of the structural properties to be similar to the vitrinite-rich, high-volatile bituminous rank. The lignite coals had similar carbon content (74.6 and 78.4 wt % for SEH and PLQ) and vitrinite reflectance but differed in ash, volatile matter, total moisture, and fixed carbon yields. The crystallite parameters [from X-ray diffraction (XRD)], the interlayer spacing, crystallite height, crystallite diameter, and the numbers of aromatic layer indicated the more inertinite-rich coal (PLQ) was slightly less ordered. Both coals were highly aromatic for lignites (f a’ values of 0.72 and 0.71 for SEH and PLQ), as the inertinite-rich components are more aromatic and polycondensed than huminite-rich (a low rank counterpart of vitrinite) coals of similar reflectance values. Image analysis of high-resolution transmission electron microscopy lattice fringes determined the aromatic fringe length distributions, with contributions between 0.25 and 0.50 nm accounting for 37.1% for PLQ, while SEH had a lower contribution of 28.0% but also a greater contribution of longer fringes (larger polycyclic aromatic hydrocarbon cluster sizes). Image analysis of the lattice fringe orientation and XRD analysis also indicated that the SEH lignite was more ordered. These two coals are potential coals for further exploration of spontaneous combustion behavior for inertinite-rich coals.

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Section: Resultsmentioning

confidence: 99%

Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State¹³C NMR, LDIMS, and HRTEM

Zhang

Zhong

et al. 2019

Energy Fuels

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Synergistic Effects of Ultrasound and Electrolysis on the Dehydration of Fine Lignite Coal

Fan

Dong

2015

Energy Tech

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A synergistic ultrasonic and electrochemical pretreatment was used for the high‐efficiency, clean removal of moisture from fine lignite coal, especially the internal moisture in filter cakes. The optimal experimental conditions were an electrolytic current of 0.75 A, an electrolytic time of 30 min, an electrolyte addition of 1000 g t−1 dried coal slime, an ultrasonic frequency of 50 kHz, and with ultrasound being used at the late electrolytic stage. the use of ultrasound improved the liquid‐phase mass transfer and cleaned the electrode surface during the electrolytic process. The total and internal filter cake moisture contents were reduced to 36 % and 6.5 %, respectively. The coal slurry particle size distribution was improved to a certain degree after synergistic pretreatment by ultrasound and electrolysis. In addition, the surface hydrophobicity of particles was enhanced and the number of pores was reduced, which was advantageous for moisture removal.

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Historical Perspective on Identifying and Controlling Spontaneous Combustion

Wang

2019

Spontaneous Combustion of Coal

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Characterization of Upgraded Brown Coal (Ubc)

Cited by 29 publications

References 7 publications

Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State¹³C NMR, LDIMS, and HRTEM

Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State¹³C NMR, LDIMS, and HRTEM

Synergistic Effects of Ultrasound and Electrolysis on the Dehydration of Fine Lignite Coal

Historical Perspective on Identifying and Controlling Spontaneous Combustion

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Characterization of Upgraded Brown Coal (Ubc)

Cited by 29 publications

References 7 publications

Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State13C NMR, LDIMS, and HRTEM

Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State13C NMR, LDIMS, and HRTEM

Synergistic Effects of Ultrasound and Electrolysis on the Dehydration of Fine Lignite Coal

Historical Perspective on Identifying and Controlling Spontaneous Combustion

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Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State¹³C NMR, LDIMS, and HRTEM

Structural Differences of Spontaneous Combustion Prone Inertinite-Rich Chinese Lignite Coals: Insights from XRD, Solid-State¹³C NMR, LDIMS, and HRTEM