Inhibitory effects of phosphorus-containing layered double hydroxides on flame characteristics and overpressure in aluminum dust explosion

To mitigate combustion-explosion hazards associated with aluminum powder in industrial settings, this research investigates the effectiveness of layered double hydroxides (LDHs) in preventing aluminum dust explosions through flame propagation studies and explosion overpressure tests. The article innovatively synthesizes phosphorus-containing layered double hydroxides powder (MgAl-LDHs-P) using the co-precipitation method. It provides a detailed comparison and discussion of the influence of MgAl-LDHs-P powder on the combustion-explosion behavior of aluminum powder under both inerting and explosion inhibition conditions. The experimental results demonstrate that the addition of an appropriate quantity of inhibitors can significantly reduce explosion intensity under inerting conditions. In contrast, the timing of inhibitor release is crucial under inhibition conditions. Furthermore, based on the analysis of explosion products and theoretical calculations, the inhibition mechanism of the material was investigated. This mechanism is primarily attributed to the heat absorption, adhesion, and its capacity to absorb free oxygen radicals. Given that LDHs have a well-established industrial-scale production amplification process, the research presented in this paper can offer new insights into safety protection measures for aluminum powder combustion-explosion.