ABSTRACT
To study the basic characteristics of soft coal similar materials of solid-gas coupling, in this paper, the molding moisture, humic acid sodium solution concentration, and aggregate size ratio to set orthogonal test with three factors and five levels are used. In the experiment, we adopted range analysis, linear regression, electromagnetic radiation, and other methods to study the influence of molding moisture, humic acid sodium solution concentration, and aggregate size ratio on the density, compressive strength, gas radiation initial velocity, permeability and elastic modulus of similar materials. The results show that the order of a significant effect on the comprehensive effect of materials is the concentration of humic acid sodium solution, aggregate size ratio, and molding moisture. The order of a significant effect on the density and permeability is molding moisture, aggregate size ratio, and humic acid sodium solution concentration. The order of a significant effect on the compressive strength and elastic modulus was humic acid sodium solution concentration, aggregate size ratio, and molding moisture. The order of a significant effect on the gas radiation initial velocity was molding moisture, humic acid sodium solution concentration, and aggregate size ratio. Permeability and humic acid sodium solution concentration presented an exponential and logarithmical relationship when the confining pressure and gas pressure are fixed, respectively. The adsorption/desorption and electromagnetic radiation characteristics of similar materials were similar to raw coal, which lays a foundation for the solid-gas coupling physically simulating experiment of soft coal.
