Suppression method of industrial Al alloy powder explosion in dry and humid environment: A low-cost intrinsic safety technology

Abstract

During the production and processing of Al alloy, a large number of small particle size powders will be produced. If the concentration of these Al alloy dust is too high under dry conditions, it will lead to dry powder explosion, and if hydrogen is produced in contact with water under wet conditions, it will lead to hydrogen explosion. This work is intended to develop a simple, cost effective technology that inerts waste Al alloy dust and minimizes its explosion hazards in different environments. Dihydrogen phosphates (KH2PO4, NH4H2PO4, Ca(H2PO4)2) are used to test the explosion flame propagation, explosion pressure, and hydrogen evolution, of waste Al alloy dust. The results show that dihydrogen phosphate can significantly reduce the flame propagation distance, speed, explosion pressure and hydrogen evolution performance of Al alloy dust, and inhibit the explosion of Al alloy dust in dry and humid environment to varying degrees. In different experiments, Ca(H2PO4)2 has the best inerting effect, low cost and simple operation, which realizes the intrinsic safety of metal dust processing process. The phosphating film on the surface of Al alloy particles blocks the generation of Al(OH)3 and retains the metal body to the greatest extent, which provides a possibility for the recycling of waste metal dust.