Experimental Study On Compound Wetting Agent Of Dust Prevetion And Water Injection For Coal Seam

The explosion of dust in coal mine and its occupational hazards severely restrict the development of China’s coal mines cause, consider of safe production in enterprise and protection of employee occupational safety and health, decreasing the concentration of dust in working face, is one of the main problems that our country urgent to solve.Coal seam water infusion is the most positive and effective measure in dedusting for the working face, and acquired the conclusion that coal surface wetting was mainly determined by interfacial tension and surface free energy of coal, in microscopic aspects the adsorption of the coal to water was mainly determined by the mutual interaction between coal macromolecules and water molecules,building the continuity equation of water in coal;the compound of anionic and non-ionic surfactants with a certain amount of inorganic salt could significantly improve the wetting properties of solution to coal; determined the surface tension of surfactants of rapid penetrant T, SDS、JFC-S、AEO-9and their contact angle on the interface of gas coal, coking coal,studied hydrophilic to coal dust by adding surfactant solution,put forward compositional formulation of complex solution and investigated its wetting effect,the result showed that composite wetting agent of0.1%rapid penetrant T+0.04%AEO-9+0.04%CaCl2made the angle of the coal-liquid interface down to10°or less in15S, composite wetting agent of0.5%SDS+0.2%AEO-9+0.04%CaCl2made the height of water wettability of coking coal dust in tube rise to30mm or more within20min.This paper firstly investigated effect from injected water inlet pressure by penetration test platform of coal sample,acquire that as the pressure of sprue increases, coal permeability improves eventually,there is almost a three cubed relation between coal permeability and the pressure of sprue,and there will be a weaken effect on permeability when water inlet pressure exceed a value. This paper studied the changeable relation between inlet pressure and water injection rate by adding composite wetting agent,compared with clean water,the inlet pressure decreased obviously,water injection rate improved,and there was a linear relationship between them,further ensured the compound formula of composite wetting agent. Finally, a field experiment done in number2671(1) working face shows that inlet water with composite wetting agent was similar with the study,the inlet water pressure decreased, and water injection rate increased apparently, the radius of the coal was improved to14-16m in working face, dust production at each step was controlled.