Improving the Wettability and Fire Retardancy of Three-Phase Foam by Simulated Sea Mud

As coal mining depths deepen and mining intensity increases, coal spontaneous combustion has become the leading cause of coal mining accidents. Sea mud is an environmentally friendly natural material rich in inorganic salts that inhibit coal oxidation. Based on sea mud, a new method of suppressing coal spontaneous combustion has been proposed by exploring the essential characteristics of sea mud three-phase foam with different concentrations. The results demonstrated that the contact angle of the three-phase foam solution with 20 wt% of sea mud decreased by 55.4° compared with that of pure water, the cross-point temperature of coal (245.85°C) increased by 16.15°C, and the peak temperature (490.57°C) increased by 16.47°C, which proved that its wettability and thermal stability were both enhanced. In conclusion, the three-phase foam with 20 wt% sea mud has been demonstrated to exhibit a superior ability to prevent the spontaneous combustion of coal.