KH2PO4/SiO2复合粉体抑制铝粉爆燃效果及机理分析

为研究KH₂PO₄/SiO₂复合粉体抑爆剂对铝粉爆燃的抑制作用，采用球磨机将KH₂PO₄和SiO₂混合研磨制备出新型的KH₂PO₄/SiO₂复合粉体抑爆剂。在哈特曼管实验装置上，开展爆燃火焰传播抑制实验，结果表明:随着KH₂PO₄/SiO₂复合粉体抑爆剂含量的增加，爆燃火焰传播长度和速度逐渐减小，当添加质量比10∶6的KH₂PO₄/SiO₂复合粉体抑爆剂时，可实现铝粉爆燃火焰传播的抑制。在20 L球形爆炸装置上，开展复合粉体抑爆剂抑制铝粉爆炸压力测试实验，结果表明:随着KH₂PO₄/SiO₂复合粉体抑爆剂含量的增加，铝粉爆炸最大爆炸压力p_max和最大爆炸压力上升速率(dp/dt)_max逐渐减小，当添加质量比10∶9的KH₂PO₄/SiO₂复合粉体抑爆剂时，可实现铝粉爆燃的完全抑制。通过KH₂PO₄粉体、SiO₂粉体与复合粉体抑爆剂对比可知，复合粉体抑爆剂对铝粉火焰传播和爆炸压力的抑制效果都优于单体粉体抑爆剂。通过对铝粉在空气中燃烧的热分析研究，从化学和物理两个方面分析了KH₂PO₄/SiO₂复合粉体抑爆剂对铝粉爆燃的抑制机理。

Effect and mechanism of KH2PO4/SiO2 composite powder in inhibiting aluminum dust deflagration

To expand the application field of environmental protection materials, a composite powder explosion inhibitor was developed to suppress the explosion disaster of aluminum powder. The KH₂PO₄/SiO₂ composite powder explosion inhibitor, a new type of explosion inhibitors, was prepared by grinding KH₂PO₄ and SiO₂ using a ball mill and used to study its inhibition effect on aluminum powder deflagration. The deflagration flame propagation inhibition experiments were carried out in a Hartmann tube experimental device. The results show that the propagation length and speed of the deflagration flame gradually decrease with the increase of the KH₂PO₄/SiO₂ composite powder explosion inhibitor content. When a KH₂PO₄/SiO₂ composite powder explosion inhibitor with the mass ratio of 10∶6 is added, the deflagration flame propagation inhibition of the aluminum powder can be realized. The pressure test experiments of the composite powder explosion inhibitor to inhibit the aluminum powder explosion were carried out in a 20-L spherical explosive device. The results show that the maximum explosion pressure (p_max) and maximum explosion pressure rise rate ((dp/dt)_max) of the aluminum powder explosion gradually decrease with the content of the KH₂PO₄/SiO₂ composite powder explosion inhibitor. When a KH₂PO₄/SiO₂ composite powder explosion inhibitor with the mass ratio of 10∶9 is added, the complete inhibition of aluminum powder deflagration can be realized. By comparison with the KH₂PO₄ powder, SiO₂ powder and composite powder explosion inhibitors, the inhibition effect of the composite powder explosion inhibitor on the flame propagation and explosion pressure of the aluminum powder is better than that of monomer powder explosion inhibitors. Through the thermogravimetric analysis of aluminum powder and KH₂PO₄, the inhibition mechanism of the KH₂PO₄/SiO₂ composite powder explosion inhibitor on aluminum powder deflagration was analyzed from both chemical and physical aspects. The KH₂PO₄ attached to the surface of composite powder explosion inhibitor absorbs heat rapidly, and the volatile participates in the explosion and combustion reaction of aluminum powder, which significantly reduces the maximum volatile content (dp/dt)_max. The SiO₂ affects the heat transfer of aluminum powder explosion and combustion, resulting in incomplete combustion and p_max reduction.