Abstract: In order to study the inhibitory effect of surfactant sodium dodecylbenzene sulfonate (SDBS) and CaCl₂ compound solution on the gas desorption of coal, coal samples from No. 4-5 coal seam in Xinjiang Sulfur Ditch were selected and HCA high pressure adsorption and desorption device was used to determine gas desorption parameters of dry coal sample, pure water, 2.5×10^-2g/mL SDBS, and coal samples soaked in SDBS and CaCl₂ mixed solution. The results show that SDBS and CaCl₂ compound solution can effectively reduce the surface tension of pure water and the contact angle of coal samples, that when the mass concentration of 2.5×10^-2 g/mL SDBS solution and the mass concentration of 2.5×10^-2 g/mL CaCl₂ solution are 1∶3, the surface tension of the solution is reduced to 24.22 mN/m, and the contact angle of coal samples is reduced to 15.175 °, that with the increase of desorption time, the gas desorption amount of coal body gradually increases in the Langmuir relationship and then stabilizes while the gas desorption rate decreases rapidly, and that when the mass concentration of CaCl₂ in mixed solution is 1.875×10^-2g/mL, the maximum gas desorption amount is 0.24 mL/g, the maximum desorption rate is 0.8×10^-2mL/(g·s), and the suppression efficiency is the highest.

Key words: surfactant, compound solution, wettability, gas desorption characteristic, inhibition efficiency