School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing , China

In order to solve the high dust density problem of the fully-mechanized coal mining face in the underground mine and to improve the operation environment, based on No. 1128 fully-mechanized coal mining face in Xingdong Mine as the study background, a study was conducted on the application of the seam water inject technology to the dust prevention of the fully-mechanized coal mining face. Based on the physical and chemical characteristics of the coal, a contact angle and the natural saturation moisture absorption curve between the wetting agent solution with the pure water and quality fraction as 0.05% were individually measured. And an optimization was conducted on the space between the water injection boreholes, water injection pressure, borehole sealing length and other technical parameters. Before and after the optimized water injection conducted, coal samplings were conducted from the boreholes. Cline-Renka algorithm was applied to the interpolation drawing of the total moisture distribution diagram and the dust control efficiency of the coal cutting and powered support pushing forward procedure were investigated. The study showed that the seam water injection with the wetting agent could effectively reduce the coal and water contact angle, could reduce the saturation moisture absorption time of the coal, could increase the saturation water adsorption volume and could improve the wetting effect of the coal. After the optimized coal injection, the average full moisture content of the coal between the two water injection boreholes would be 2.23% higher than the previous water injection plan,and the wetting radius would be increased by 3.5 m. In the coal cutting processing, the average dust control efficiency of the total dust and respirable dust were individually improved by 25.42% and 26.39%. During the process of the powered support pushing forward, the average dust control efficiency of the total dust and respirable dust were individually improved by 23.39% and 25.30%.