Study of effect and mechanism of flame retardation-bursting liability reduction based on chelating water injection wetting agent in coal seam

Abstract

As coal mines continue to deepen high-intensity mining, the two disasters of coal seam rock burst and spontaneous combustion obviously have a trend of compound occurrence. How to achieve the integrated prevention and control of the two disasters is an important guarantee to realize coal mine safety. As a result, it is very important to select a coal seam water injection additive that can not only reduce the bursting liability, but also prolong the spontaneous combustion period of coal. In this paper, the chelating wetting agent was chosen to soak the coal, and the mass changed and carbon-containing functional groups during the coal oxidation process were studied by thermogravimetric and X-ray photoelectron spectroscopy, and tested the strength of coal by uniaxial compression experiment, and the scanning electron microscopy and low-temperature N2 adsorption were used to analyze the pore structure of coal. The experiment results show that the mass of the raw coal, the mass of the coal soaked in FeSO4 solution, and the mass of the coal soaked in the chelating wetting agent were reduced by 30.01%, 34.62% and 19.00%, respectively. The amount of the carbon–carbon bond and carbon–hydrogen bond decrease and the amount of carbon–oxygen bond increase in the chelating wetting agent soaking coal were less than in the water soaking coal and FeSO4 solution soaking coal. After soaking in the chelating wetting agent, the mechanical properties of the coal were changed, and the uniaxial compressive strength was reduced by 52.55%. The fractal dimension of the coal surface increased from 1.8448 to 1.8575, the average pore diameter in the coal was increased, the specific surface area was reduced, and the number of mesopores also increased. The above results can provide an important theoretical basis for the integrated prevention and control of rock burst-spontaneous combustion compound disaster.