Fire prevention and control using gel-stabilization foam to inhibit spontaneous combustion of coal: Characteristics and engineering applications

摘要

In order to address the issue of spontaneous combustion in coal mines during the mining process, we have proposed gel-stabilized foam (GSF) that can prevent and control fires in coal mines. In this work, GSF was successfully prepared by forming silica gel structure in the bubble film using compound foaming agent (CFA), modified polyethoxylated silicone (MPS), water glass (WG) and coagulant (NaHCO3). The effect of different concentrations of components on the properties of GSF was analyzed by studying the gelation time, foamability, and stability of the GSF. The foamability and foam stability indicated that the viscosity of foaming solution increases with the increase in the concentrations of NaHCO3 and WG. Furthermore, a higher viscosity of the foaming solution results in a poorer foaming performance, while it prolongs the foam stability. The extent of oxidation of hydroxyls and methylene on the coal sample surface treated with GSF was low. The fire-extinguishing experiments showed that the GSF could nicely cover the surface of burning coal, significantly reduce the fire source temperature, thermal radiation and emission of CO, and realize stable fire extinguishing without re-burning. The results of the on-site application of GSF in the withdrawal of 1301 working face of Shandong Longyun Coal Industry Co., Ltd., China suggest that the GSF effectively inhibited the oxidation of crushed coal body, significantly reduced the temperature of the coal body, and ensured a safe withdrawal of the rack on the working face.