Study on compressive performance of remoding coal under low temperature environment

Abstract

In order to study the compressive properties of low-temperature remolded coal, realize safely and rapidly uncovering coal seam in crosscut, and prevent coal and gas outburst, the coal samples were crumbled, selected and suppressed to obtain the remolded coal specimens. The uniaxial compression experiment was carried out under the coupling of a certain moisture content ( 0%, 4%, 8%, 12%, 16% ) and a certain temperature (−40 ℃, −30 ℃, −20 ℃, −10 ℃, −0 ℃, 20 ℃) to analyze the failure characteristics and mechanical properties of remolded coal. The experiment results indicate that: at normal temperature (20 ℃) and 0 ℃, the compressive strength decreases increasingly with the increase of water content. Under the freezing temperature, the frost heaving force inside the coal sample gradually decreases with the decrease of temperature, and the compressive strength of remolded coal is obviously enhanced. Under the coupling effect of low temperature (−40 °C) and high water content (16%), the compressive strength, peak stress and peak strain of the remoulding coal body reached the maximum, which were increased by 164.24%, 165.71% and 685.72% respectively.

Keywords

• remolded coal
• low-temperature
• moisture content
• mechanical properties
• compressive strength