Inhibition effects of aluminum dust explosions by various kinds of ammonium polyphosphate

In this work, vinyltriethoxysilane (A151) and 3-aminopropyltriethoxysilane (KH550) were used to modify ammonium polyphosphate (APP), showing that the dispersibility of APP could be improved remarkably by A151 and KH550. The maximum explosion pressure of aluminum dust explosion decreased with the addition of APP, A151-APP (APP-A) and KH550-APP (APP-B), with the exception of the case where the inerting ratio (α) of APP-A was less than 0.4. After the addition of APP-B, there was little difference in flame propagation behavior and explosion pressure compared with that of adding APP, indicating that APP-B could retain the inhibition performance of APP compared with APP-A. When the inerting ratios of APP, APP-A and APP-B were 1.2, 1.4 and 1.4, respectively, the aluminum dust explosion could be completely inhibited. The explosion residues of aluminum dust/APP mainly consisted of Al2O3, P-containing and N-containing compounds. It could be analyzed that APP exerted the inhibition effect through both chemical and physical effects. [Display omitted] •APP is modified by A151 and KH550 to improve the dispersibility of APP.•The inhibition effects of APP, A151-APP and KH550-APP are studied.•KH550-APP can maintain the inhibition efficiency of APP compared with A151-APP.•Inhibition mechanism of APP for aluminum dust explosion is analyzed.