## 1 Introduction  
Gas explosion is an extraordinary serious coal mine disaster that can cause massive damage and casualties. In order to reduce the impact of coal mine gas explosion, researchers have carried out a lot of research works. On the one hand, the refuge chamber has been widely investigated and used for miners who are unable to escape during an accident, which can provide basic survival conditions [1; 2; 3]. [PERSON] et al. simulated and analyzed the structure strength of a coal mine mobile refuge chamber under gas explosion load by a finite element method [4]. [PERSON] et al. simulated and analyzed the air pressure distribution law in the mine refuge chamber [5]. [PERSON] et al. studied the design and optimization of the refuge chambers based on the simulation of the gas explosion pressure fields [6]. [PERSON] et al. studied the relationship between the propagation regulation about shock wave of gas explosion and the lineway cross-sectional area [7]. [PERSON] et al. established the underground mine tunnel model and the refuge chamber model by using the finite element software ANSYS/LA-DYNA, the propagation of methane/air mixture blast waves, and the fluid-structure interactions were also simulated by the Arbitrary Lagrange-Euler (ALE) method [8]. On the other hand, the suppression of gas explosion in the coal mine is also significant for the safety of mine production. Methane is the major component of mine gas and its explosion limits is 5-15%. In the previous studies, water mists [9; 10; 11; 12], inert gas [13; 14; 15; 16], and chemical powders [17; 18; 19; 20; 21] have been used to suppress the methane explosion. Because of its excellent performance on methane explosion suppression, chemical powders are studied extensively. In recent years, the composite powders were appreciated and studied widely for its synergistic effect on the explosion suppression. [PERSON] et al. systematically studied the relationship between the particle size distributions, specific surface area, and the explosion suppression effectiveness of the rock dusts [22]. [PERSON] et al. fabricated a new type fire suppressant with core-shell structure while using zeolites and NaHCO\({}_{3}\)[23]. The composites could extinguish the oil fire with less powder amount and shorter time when comparing with the common BC (... ) powders. [PERSON] et al. report a novel procedure to fabricate multilayer composite biofilms based on halloysite nanotubes (HNTs) and sustainable polymers [24]. The thermal properties analysis of the nanocomposite indicated that the chitosan/halloysite layer generates a flame retardant action on the biomaterials and the multilayer morphology confers a fire resistance to the nanocomposite. In our previous work, the NaHCO\({}_{3}\)/red-mud composite powders were prepared and its suppression effect on the methane explosion was tested in detail [25]. Due to the synergistic suppression effect between NaHCO\({}_{3}\) and red-mud, the NaHCO\({}_{3}\)/red-mud composite powders exhibited better suppression properties than that of the pure NaHCO\({}_{3}\) and red mud powders. Thus, the use of composite powders gradually became an important development trend for the gas explosion suppression. Red mud is the waste residue of alumina industry, which is mainly composed of Al\({}_{2}\)O\({}_{3}\), CaO, SiO\({}_{2}\), and Fe\({}_{2}\)O\({}_{3}\), and caused serious environmental pollution. The recycle and utilization of red mud have become an urgent problem. On this condition, many works have been done to find the novel utilization of red mud [26; 27; 28; 29; 30]. In our previous research, the red mud was modified by a facile method and presented a considerable suppression property on methane explosion [31]. Producing methane explosion suppression reagents with red mud could both solve the pollution problem and bring considerable economic value. NH\({}_{4}\)H\({}_{2}\)PO\({}_{4}\) is a kind of common fire-extinguishing agent.