Study on Deformation Laws of Briquette Coal Under Adsorbing Different Gases

In order to explore the deformation characteristics of briquette coal adsobing CH₄, N₂ and CO₂ under different pressure, this paper studies the deformation laws of briquette coal in the adsorption process of these three kinds of gas by using the adsorption-desorption test system for high-pressure gas coal rock. The results show that: the adsorption process for different gases of briquette coal under different pressure includes 3 stages, such as vacuum deformation, adsorption swelling deformation and desorption compression deformation, and the swelling deformation law of three kinds of gase is similar; the axial deformation and circumferential deformation are increasing gradually. The strain-time relation in the process of adsorption swelling deformation accords with the form of Langmuir equation. The adsorption expansion deformation of briquette coal to three kinds of gas under the same temperature and adsorption pressure is from big to small in order of CO₂, CH₄, N₂. The annular strain of the three kinds of gas expansion and deformation is larger than the axial strain, and the deformation difference increases with the increase of the pressure in two directions.