Study on the Effect of Retarded Acid on the Initial Velocity of Gas Emission in Anthracite
Retarded acid is of great significance to reduce the reaction rate of coal and improve the recovery rate of coalbed methane.Taking the anthracite of a mine in Guizhou as the research object,tests on static dissolution,initial velocity of gas emission,low-temperature CO2 adsorption and infrared spectroscopy were carried out.The influence mechanisms of pore structure and number of oxygen-containing functional groups of coal samples on the initial velocity of gas emission in coal were analyzed from physical and chemical perspectives.The results show that the acidification retarding effect is the best when the mass concentration of acetic acid is 5％,and the retarding rate is 41.03％.Compared with the original coal sample,the initial velocity of gas emission of hydrofluoric acid acidified coal increases.On one hand,hydrofluoric acid improves the pore connectivity of the coal samples,increases the number of transition pores and large pores,and reduces the specific surface area of the coal samples.On the other hand,the number of oxygen-containing functional groups in the coal samples increases after hydrofluoric acid treatment,which inhibits the adsorption of gas by coal.Compared with the original coal samples,the initial velocity of gas emission of retarded acid acidified coal decreases.This is because the action of retarded acid increases the number of micropores of the coal samples,increases the specific surface area of the coal samples,and reduces the number of oxygen-containing functional groups of the coal samples.Therefore,the surface structure is more complex,which promotes the adsorption of coal to gas.The research results have laid a theoretical foundation for the acidizing stimulation technology of coalbed methane in this mining area of Guizhou.
Retarded acidAnthraciteInitial velocity of gas emissionPore structureOxygen-containing functional groups
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维普
