煤炭产业是我国国民经济的支柱产业，但在煤炭开采过程中发生的瓦斯煤尘爆炸事故严重危害人民的生命健康，造成巨大的经济损失恶劣的社会影响。矿井瓦斯煤尘爆炸事故会产生高压、高温、火焰和大量的有毒有害气体，化学活性较好的NH₄H₂PO₄粉体和具有抑烟阻燃效果的Mg(OH)₂粉体组成的复配粉体应用于煤矿抑爆领域具有巨大的潜在价值。

采用可视化气体-粉尘瞬态爆炸实验系统，探究瓦斯煤尘预混爆炸火焰传播特性，开展不同配比和不同浓度的Mg(OH)₂-NH₄H₂PO₄复配粉体抑制9种爆炸最猛烈工况实验，研究复配粉体的粉体配比和粉体浓度对瓦斯煤尘预混爆炸火焰传播规律和气态产物特性的影响，分析Mg(OH)₂和NH₄H₂PO₄抑制瓦斯煤尘预混爆炸协同增效规律。研究结果为矿井瓦斯煤尘爆炸事故防控提供理论依据。主要结论如下：

(1) 瓦斯煤尘预混爆炸火焰形态主要有圆形、椭圆形、指尖形、平面形和郁金香形。加入煤粉后，火焰传播过程中不规则的火焰形态增多，煤尘云提升了爆炸体系内的混乱程度，加大了管道内流体的湍流度，郁金香形火焰的结构被破坏，存在时间大幅缩短，火焰锋面的光滑程度和清晰程度降低。

(2) 在瓦斯浓度为8%时，爆炸体系为富氧状态，褐煤和气煤煤尘云浓度为500 g/m³、无烟煤煤尘云浓度为700 g/m³时爆炸最猛烈，煤尘云浓度存在一个临界值使爆炸最猛烈，但超过临界值时会对火焰的传播起抑制作用，煤的变质程度越低，火焰传播速度、爆炸压力、火焰温度越大。瓦斯浓度为10%和12%时，爆炸体系为贫氧状态，加入煤粉后，褐煤、气煤和无烟煤煤尘云浓度为130 g/m³时爆炸最猛烈，煤的变质程度越低，火焰传播速度、爆炸压力、火焰温度越小。

(3) Mg(OH)₂-NH₄H₂PO₄复配粉体对瓦斯煤尘预混爆炸九种最猛烈工况的火焰传播速度、爆炸压力和火焰温度均有抑制作用。粉体浓度在200–1000 g/m³范围内，单一NH₄H₂PO₄粉体、1:6、1:5、1:4、1:3和1:2配比粉体均是在粉体浓度为1000 g/m³时达到最佳抑制效果。

(4) 六种配比的Mg(OH)₂-NH₄H₂PO₄复配粉体对九种爆炸最猛烈工况都具有抑制作用。Mg(OH)₂粉体的加入，提升了复配粉体的抑爆效能，复配粉体中Mg(OH)₂质量占比从0提升至20.00%（粉体配比为1:4）时，抑制效能逐渐提升，超过这一临界值，即Mg(OH)₂质量占比从20.00%提升至33.33%时，抑制效能逐渐减弱，Mg(OH)₂和NH₄H₂PO₄体现出抑制瓦斯煤尘预混爆炸的协同增效作用。复配粉体的配比为1:4时，复配粉体抑制瓦斯煤尘预混爆炸火焰传播特性的效果最佳，而单一NH₄H₂PO₄粉体的抑制效果最差。不同粉体配比抑制瓦斯煤尘预混爆炸火焰传播特性效能排序为1:4>1:5>1:6>1:3>1:2>NH₄H₂PO₄。

(5) 六种配比的Mg(OH)₂-NH₄H₂PO₄复配粉体对CO和CO₂具有极强的吸附作用，Mg(OH)₂的加入提升了复配粉体对有毒有害气体的吸附效能。随着复配粉体中Mg(OH)₂质量占比的提高，复配粉体对CO和CO₂的抑制作用先提升再减弱。Mg(OH)₂的质量占比从0提升至20%，复配粉体对CO和CO₂的吸附作用增强，当超过这一临界值，吸附作用减弱，但加入Mg(OH)₂后的复配粉体对CO和CO₂的吸附作用远远强于单一NH₄H₂PO₄粉体，Mg(OH)₂与NH₄H₂PO₄两者体现抑制瓦斯煤尘预混爆炸有毒有害气体的协同增效作用。Mg(OH)₂的加入大幅提升了复配粉体对CO和CO₂的吸附作用，配比为1:4的复配粉体对CO和CO₂的吸附作用最强。Mg(OH)₂与NH₄H₂PO₄体现出抑制瓦斯煤尘有毒有害气体的协同增效作用。

(6) 六种配比的Mg(OH)₂-NH₄H₂PO₄复配粉体对九种爆炸最猛烈工况都具有抑制作用。随着复配粉体中Mg(OH)₂质量占比的提高，复配粉体对瓦斯煤尘预混爆炸火焰传播速度、火焰温度、爆炸压力、CO和CO₂的抑制作用先提升再减弱。同时Mg(OH)₂-NH₄H₂PO₄复配粉体对瓦斯煤尘预混爆炸的有效抑制，O₂和CH₄的含量具有一定的提升。Mg(OH)₂粉体的加入，提升了复配粉体的抑爆效能，复配粉体中Mg(OH)₂质量占比从0提升至20.00%（粉体配比为1:4）时，抑制效能逐渐提升，超过这一临界值，即Mg(OH)₂质量占比从20.00%提升至33.33%时，抑制效能逐渐减弱，Mg(OH)₂与NH₄H₂PO₄体现出抑制瓦斯煤尘预混爆炸和有毒有害气态产物的协同增效作用。

The coal industry is a pillar of China’s national economy, but gas and coal dust explosions during coal mining seriously endanger people’s lives and health, causing substantial economic losses and harmful social impacts. The mine gas and coal dust explosion accidents produce high pressure, high temperature, flame, and a lot of toxic and harmful gases, and the compound powder composed of NH₄H₂PO₄ powder with good chemical activity and Mg(OH)₂ powder with smoke suppression and flame retardant effect is of great potential value when applied in the field of coal mine explosion suppression.

The visualised gas-dust transient explosion experimental system was applied to investigate the flame propagation characteristics of gas and coal dust premixed explosion and to carry out experiments with different ratios and concentrations of Mg(OH)₂-NH₄H₂PO₄ compound powder to suppress the nine most explosion conditions, to study the effect of the powder ratio and powder concentration of compound powder on the gas The effect of the flame propagation law and gaseous product characteristics of the coal dust premixed explosion, and the synergistic effect of Mg(OH)₂ and NH₄H₂PO₄ on the suppression of gas and coal dust premixed explosion. The study results provide a theoretical basis for preventing and controlling gas and coal dust explosions in mines. The main conclusions are as follows:

(1) The explosion flame forms of gas and coal dust premixed are mainly round, oval, fingertip, flat, and tulip-shaped. The addition of coal dust increases the irregular flame pattern during flame propagation, the coal dust cloud enhances the level of confusion within the explosion system, increases the turbulence of the fluid in the pipe, the structure of the tulip-shaped flame is destroyed, the existence time is significantly reduced, and the smoothness and clarity of the flame front are reduced.

(2) In the gas concentration of 8%, the explosion system for the oxygen-rich state, lignite and gas coal dust cloud concentration of 500 g/m³, anthracite coal dust cloud concentration of 700 g/m3 when the most violent explosion, coal dust cloud concentration there is a critical value to make the most violent explosion, but more than the critical value will play a suppressive role in the propagation of flame, the lower the degree of deterioration of coal, the flame propagation rate, explosion pressure, the flame temperature is greater. The explosion system is oxygen-poor when the gas concentration is 10% and 12%. After adding pulverised coal, lignite, gas coal, and anthracite coal dust cloud concentration of 130 g/m^3, the most violent explosion, the lower the degree of coal deterioration, the flame propagation velocity, explosion pressure, and flame temperature is smaller.

(3) Mg(OH)₂-NH₄H₂PO₄ complex powders inhibited flame propagation rate, explosion pressure, and flame temperature for the nine most violent working conditions of gas and coal dust premix explosions. Powder concentrations in the 200-1000 g/m³, single NH₄H₂PO₄ powder, 1:6, 1:5, 1:4, 1:3, and 1:2 ratio powders all achieved the best suppression effect at a powder concentration of 1000 g/m³.

(4) The six ratios of Mg(OH)₂-NH₄H₂PO₄ complex powders inhibited all nine of the most violent explosion conditions. The Mg(OH)₂ powder was added to increase the inhibition effectiveness of the powder compound, with the percentage of Mg(OH)₂ mass in the powder compound increasing from 0 to 20.00% (1:4 powder ratio), the inhibition effectiveness gradually increased beyond this threshold value, i.e., the inhibition effectiveness gradually decreased when the mass proportion of Mg(OH)₂ increased from 20.00% to 33.33%, and Mg(OH)₂ and NH₄H₂PO₄ showed a synergistic effect of inhibiting the explosion of gas and coal dust premix. The best inhibition of the flame propagation characteristics of gas and coal dust premixed explosions was achieved with a 1:4 ratio of the compounded powders, while the worst inhibition was achieved with a single NH₄H₂PO₄ powder. The effectiveness of the different powder ratios in suppressing the flame propagation characteristics of gas and coal dust premixed explosions was ranked as 1:4>1:5>1:6>1:3>1:2>NH₄H₂PO₄.

(5) The six ratios of Mg(OH)₂-NH₄H₂PO₄ complex powders have a powerful adsorption effect on CO and CO₂, and the addition of Mg(OH)₂ enhances the adsorption efficiency of the complex powders on toxic and hazardous gases. As the mass proportion of Mg(OH)₂ in the compounded powder increased, the inhibition of CO and CO₂ by the compounded powder increased and then decreased. It is much stronger than NH₄H₂PO₄ powder, Mg(OH)₂ and NH₄H₂PO₄ reflect the synergistic effect of inhibiting the gas coal dust premixed explosion of toxic and harmful gases. The addition of Mg(OH)₂ significantly enhanced the adsorption of CO and CO₂ by the compounded powders, with the ratio of 1:4 showing the strongest adsorption of CO and CO₂, and Mg(OH)₂ and NH₄H₂PO₄ showing the synergistic effect of toxic and harmful gaseous products..

(6) The six ratios of Mg(OH)₂-NH₄H₂PO₄ were found to inhibit all nine of the most violent explosion conditions. As the mass proportion of Mg(OH)₂ in the compounded powders increased, the inhibitory effect of the compounded powders on the flame propagation rate, flame temperature, explosion pressure, CO, and CO₂ of the gas-dust premixed explosion increased and then decreased. At the same time, Mg(OH)₂-NH₄H₂PO₄ compound powder on the effective suppression of gas and coal dust premixed explosion, O₂ and CH₄ content has a certain increase. Mg(OH)₂ powder addition enhances the compound powder suppression effectiveness, compound powder Mg(OH)₂ mass ratio from 0 to 20.00% (powder ratio of 1:4), suppression effectiveness gradually increased, more than This threshold value, i.e., the inhibition effectiveness gradually decreased when the mass proportion of Mg(OH)₂ was increased from 20.00% to 33.33%, Mg(OH)₂ and NH₄H₂PO₄ demonstrated the synergistic effect of inhibiting gas and coal dust premixed explosion and toxic and harmful gaseous products.