Study On Desulfurization Mechanism Of Coal Particle Under Different Temperature Conditions And Its Application

With the increase of coal mining depth in our country, the temperature of coal seam changed significantly. The influence of temperature on occurrence of methane in coal seam cannot be ignored. Therefore, it was of great significance to study the relationship between temperature and methane desorption in coal seam. At present, the temperature had rarely been as an important indicator when gas content was measured. In our study, desorption amount of coal gas under different temperature were studied by using the method of theoretical analysis, experimental measurement and field studies, and then the calculation equation of gas content affected by the temperature was concluded finally. When coal samples in experimental mine were measured, the adsorption constant of gas adsorption in desorption equation affected by temperature were determined. The targeted scheme of gas drainage by the field industrial test was put forward, and the gas extraction rate had improved by 5%.The main conclusions of this paper were as followed:(1) By theoretical analysis of coal gas adsorption and desorption characteristics, the results showed that under different environmental temperature, coal gas adsorption constant b was related to temperature, adsorption constant a was associated with specific surface area of coal. Further study found that the influence of temperature on adsorption constant a accorded with exponential function. And parameter α was introduced considering the different occurrence conditions of gas. Combined with gas state equation and langmuir equation, the equation of gas content affected by the temperature was concluded.In this study, The coal samples of Liyazhuang coal mine # 2 was selected, and two different adsorption experiments of methane injection were conducted under different temperature(20℃~45℃) or pressure by applying methane desorption WY98-A. By studying the relationship between the langmuir adsorption constant a(or b) and temperature, the value of parameters α was derived, which improved the theoretical equation of gas content affected by the temperature.By measuring the temperature in coal seam of Liyazhuang coal mine, the function relationship between temperature and the depth of coal seam could be derived. In the calculation of gas content in 2602 working face of coal seam, the effects of temperature on gas content in coal seam were compared and the reasons for unideal gas extraction in the past were analyzed. Considering source analysis of coal gas content in 2602 working face, the technology of gas drainage in mine coal seam and adjacent seams was combined with the roof drilling and high fracture drilling in the high drilling field floor, and the expected extracted time was determined. By the field industrial test, the capacity of gas drainage could reach more than 45% in the extraction test for 14 months, which could assure the basic security and reliability of coal seam mining. This study could provide theory and practice safeguard for gas drainage design and applying temperature to determine gas content.