卤盐阻化剂在采空区煤自燃防治中的多维阻化效果研究OA

Spraying inhibitors in the goaf can prevent and control coal spontaneous combustion.To investigate the effects of differ-ent halogen salt inhibitors and their mass fractions on the prevention and control of spontaneous combustion of residual coal in the goaf,the 51102 working face of Jintong Mining Co.,Ltd.was taken as the research background(the mined coal seam is Class Ⅰeasy-to-spontaneous-combustion coal seam,and the coal dust is explosive,leading to a high risk of spontaneous combustion).The in-hibition performance of inhibitors was analyzed through temperature-programmed experiments coupled with gas chromatography and thermogravimetric tests,and the optimal inhibitor type and spraying concentration were optimized.Furthermore,the inhibition mechanism of inhibitors on coal spontaneous combustion was revealed via molecular dynamics simulation.The results show that the inhibition efficiency of different inhibitors ranks as MgCl2·6H2O>CaCl2·2H2O>NaCl.The difference in inhibition performance is small at low temperatures but gradually increases with rising temperature.The inhibition performance of halogen salt inhibitors is positively correlated with their mass fractions;however,the growth rate of inhibition efficiency gradually decreases with increasing mass fraction.Considering both inhibition effect and economic benefit,MgCl2·6H2O with a mass fraction of 15%-20%is determ-ined as the optimal inhibitor.The interaction energies of the three inhibitor systems follow the order of NaCl<CaCl2<MgCl2,indic-ating that MgCl2 exhibits the strongest adsorption capacity on the coal surface.For MgCl2 systems with five mass fractions,an inhibi-tion adsorption peak appears at approximately 30 Å(1 Å=10-10 m).The inhibition adsorption peak is relatively high at a mass frac-tion of 15%-20%,and the mean square displacement and diffusion coefficient of MgCl2 molecules in the system are small under this condition,demonstrating the strongest adsorption capacity of MgCl2 on the coal surface.Based on the optimization results,a solu-tion with a mass fraction of 15%MgCl2·6H2O solution was applied as the inhibitor for coal spontaneous combustion prevention in the goaf.The measured temperatures at monitoring points in the goaf stably remained below 60℃,showing an excellent inhibition effect.