THERMAL SCIENCE

International Scientific Journal

EFFECT OF LOW TEMPERATURE DAMAGE ON TENSILE STRENGTH OF COAL UNDER THE LIQUID NITROGEN FREEZING

ABSTRACT
To explore the influence of low temperature damage on the tensile strength of coal under the liquid nitrogen freezing, the Brazilian splitting tests are conducted on the bedding coal in this paper. The tensile strength, macro fracture surface morphology, failure path and micro-structures of the coal samples before and after liquid nitrogen treatment were analyzed systematically. The results show that the tensile strength of coal after liquid nitrogen freezing is reduced, the macro fracture surfaces with greater roughness or fractal dimension were induced in the coal treated by liquid nitrogen freezing during the Brazilian splitting tests, the opening and number of the failure paths of coal after liquid nitrogen freezing increase significantly, and the microscopically, the bedding and matrix structures of coal are destroyed due to the temperature stress caused by large temperature difference between the liquid nitrogen and coal matrix.
KEYWORDS
PAPER SUBMITTED: 2020-04-26
PAPER REVISED: 2020-07-25
PAPER ACCEPTED: 2020-08-07
PUBLISHED ONLINE: 2020-11-27
DOI REFERENCE: https://doi.org/10.2298/TSCI2006979S
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2020, VOLUME 24, ISSUE Issue 6, PAGES [3979 - 3986]
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© 2022 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence