Suppression effect and mechanism of melamine polyphosphate /zinc borate composite suppressant on aluminum dust explosion

To mitigate potential hazards of aluminum (Al) powder explosions, a green suppressant called MPP/ZB has been successfully produced using mechano-chemical technology. The suppressant consists of melamine polyphosphate (MPP) and zinc borate (ZB). This study examined the suppression effect of various mass concentrations of the composite suppressant on Al dust explosion. The results indicate that, with the addition of 100 wt% of MPP/ZB to the 300 g/m 3 aluminum powder, P max and K st decreased from 0.701 MPa and 8.7 MPa·m/s to 0.13 MPa and 0.2 MPa·m/s, respectively, effectively suppressing the explosions. Moreover, TG-DSC analysis of the suppressant and XPS/SEM examination of the explosion residues further revealed that the addition of ZB enhances the inhibitory effect of MPP on Al dust explosions. The H 2 O, Zn (OH) 2 and ZnO produced by ZB decomposition reduce the concentration of NH 3 generated by MPP decomposition, which may have a combustion promoting effect on Al dust.