Fire extinction behavior of fly ash with different gas driving pressures on metal magnesium fires based on pneumatic conveying equipment

Metal fires are difficult to extinguish with traditional extinguishing agents, while special fire-extinguishing agents are difficult to obtain. Thus, the possibility of using fly ash to extinguish metal fires was explored, and the effects of different driving gas pressures on the accumulation and extinguishing efficacy of fly ash were studied carefully by means of a self-made pneumatic conveying device. The results show that fly ash can effectively extinguish metal magnesium fires, and the accumulation and extinguishing efficacy of fly ash improves with increasing gas driving pressure. Especially, the fire extinction time of fly ash on metal magnesium fires is as low as 20 s without reignition at a gas driving pressure of 0.8 MPa. Fly ash can remain high thermal stability at above 900°C, forming a thermal insulation layer that exerts strong smothering and isolation effects against metal magnesium fires, which is a high-efficient and economical fire-extinguishing agents to suppress metal magnesium fires.