Research Status and Progress of Diffusion Characteristics of Gas from Coal Particles

In this paper，systematical study was carried out on the diffusion characteristics of gas from coal particles，it was believed that the research results in this field can be divided into the linear diffusion theory，the gas diffusion theory based on the time－varying diffusion coefficient and the multi－factor diffusion theory．On this basis and through a detailed analysis，it was believed that the current research direction of the diffusion characteristics of gas from coal particles can be summarized as follows:①the study on gas diffusion characteristics in consideration of the coal particle shape; ② the influence of adsorption and desorption lagging on the diffusion characteristics of gas from coal particles; ③the study on diffusion characteristics of gas from coal particles under the action of multi－physical field coupling．