| With the exploitation of low sulfur coal seam,the emission and disaster accidents caused by the abnormal enrichment of hydrogen sulfide gas appear continuously,which seriously threatens the safety of coal mine.Taking the 4-2 coal seam of CuiJiaGou coal mine as the research object,the sedimentary environment characteristics of the coal seam containing hydrogen sulfide,the influencing factors of hydrogen sulfide adsorption and the development of modified alkali liquor were studied.(1)Based on the chemical genetic mechanism of hydrogen sulfide,through the analysis of paleosalinity characteristics,isotopic characteristics,redox characteristics and hydrodynamic characteristics,the results show that the sedimentary environment of the 4-2 coal seam in CuiJiaGou is continental,and shows anaerobic weak reducing sedimentary conditions.(2)By analyzing the influence of coal particle size,coal pore structure,coal metamorphism,macerals and temperature on the adsorption of hydrogen sulfide,it is concluded that the adsorption capacity of hydrogen sulfide in coal seam has a positive correlation with coal particle size,RO,and pressure,but a negative correlation with temperature,and when the pressure is greater than 5MPa,the increase of the adsorption capacity of hydrogen sulfide gradually begins to slow down.Under the same pressure temperature condition,the adsorption experiments of hydrogen sulfide,methane and nitrogen were carried out.T he results showed that the adsorption capacity of coal for hydrogen sulfide,methane and nitrogen was H2S>N2>CH4.(3)In order to solve the problem of secondary escape in the absorption of hydrogen sulfide by ordinary lye,the modified lye was developed by single factor experiment and multi factor experiment.It was put forward that the optimal ratio of the modified lye was:the concentration of sodium carbonate solution was 2.25%,the concentration of surfactant was 0.45%,and the CuiJiaGou coal mine as the research object,the field tests of treating hydrogen sulfide by spraying ordinary alkali solution and modified alkali solution are carried out respectively.The results show that the average removal rate of modified alkali solution is 93.5%,so the treatment of hydrogen sulfide concentration by modified alkali solution can effectively reduce the hydrogen sulfide concentration to the safe value(6.6ppm),and the treatment effect is significant. |
