Open AccessCHANGES IN THE COMPOSITION AND PROPERTIES OF THE HOST ROCKS OF COAL DEPOSITS IN YAKUTIA UNDER THE INFLUENCE OF CRYOGENESIS
Author(s) -
Andrey Melnikov,
Ze Zhang,
Н. Н. Гриб,
Camil Jakub Shabo
Publication year - 2020
Publication title -
izvestiâ nacionalʹnoj akademii respubliki kazahstan. seriâ geologii i tehničeskih nauk
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.323
H-Index - 9
eISSN - 2518-170X
pISSN - 2224-5278
DOI - 10.32014/2020.2518-170x.113
Subject(s) - coal , geology , coal field , siltstone , borehole , mineralogy , geochemistry , coal measures , uniaxial tension , ultimate tensile strength , coal mining , geotechnical engineering , materials science , composite material , chemistry , geomorphology , organic chemistry , facies , structural basin
The results of laboratory tests carried out on rock samples of the Kharbalakhskoye coalfield located in Central Yakutia revealed significant secondary changes having taken place in the host rocks containing the coal. Evidently, under transformation processes, it is not only the composition of the rocks that had changed, but also the nature of structural bonds that have a great influence on their physical and mechanical properties. Thus, the ultimate strength values of coal-containing sandstone and siltstone samples under uniaxial compression vary from 20 to30 MPa, while under uniaxial tension, the ultimate strength values range from 6 to 10 MPa. These relatively low numerical values pertaining to the physicomechanical properties of rocks, which are generally atypical for long-flame coal deposits, are almost 50% lower than those of analogous rocks hosting other coal deposits in Russia. It is considered that the mechanical strength properties of the rocks of the Kharbalakhskoye field are due to significant cryogenic processes. A comparative analysis of the properties of core samples obtained from boreholes drilled in 2019 with samples from a quarry obtained several decades ago reveals signs of transformation of rocks in the Kharbalakhskoye field due to phase transitions of freezing and thawing water.