Experimental Study On Gas Loss Quantity Of Tecnonic Coal

The tectonic coal has characteristics with high energy storage, large specific surface area, high porosity, initially fast gas desorption, which are the causes of the uncertainty of gas content in tectonic coal. This paper took the research of tectonic coal gas loss as the core, rapid and accurate determination of seam gas content as the ultimate goal. According to gas content and gas desorption experiment on the native structure coal and tectonic coal from Huaibei mining and Lu’an Mining, the factors of the gas desorption rate, the gas desorption and the residual gas content were analysised, the relationship between the initial gas desorption law and gas pressure, as well as the residual gas content and gas content, was established. Finally, the method that was used to determine the tectonic coal gas loss in different stages was analyzed and demonstrated by the field test.Through the research of tectonic coal gas loss, here are some cognitions and conclusions of this paper.(1) Under the same experimental conditions, the total gas content of undeformed soal is almost the same as that of tectonic coal; The main factors influencing the gas desorption rate, the residual gas content and the gas loss quantity of tectonic coal and uddeformed coal include metamorphic degress, failure degree, gas pressure, gas content, size, temperature, moisture, etc.(2)The initial gas desorption and desorption time had a good relationship with the logarithmic fitting:Q= Aln(t)+b. In this formula, the coefficient A has nothing to do with desorption time, but increases with the as the gas pressure increases. Therefore, we established a functional relationship between coefficient A and gas pressure:P=deBA;(3)This study found that after undeformed coal and tectonic coal in Changcun Mining was exposured for a period of time, the residual gas quantity and the gas pressure had a good function relationship, as follows: according to the projections of coal seam pressure;(4) The 1/2t method used to calculate gas loss quantity is suitable for undeformed coal with metamorphic grade or low gas pressure, but not for the tectonic coal. By using 1/2t method to calculate the tectonic coal gas loss, with the increasing exposure duration and gas pressure, the gap between projected loss of tectonic coal gas and actual gas content values became larger and larger.(5)This study found that after undeformed coal and tectonic coal in Changcun Mining was exposured for a period of time, the residual gas quantity and the gas content had a good function relationship, as follows:...