Experiment study on the explosion suppressing characteristics and mechanism of melamine cyanurate and ammonium dihydrogen phosphate for lignite dust

To solve the problem of spontaneous combustion and dust explosion during storage and transportation of lignite, this work investigates the efficacy of melamine cyanurate (MCA) and ammonium dihydrogen phosphate (ADP) dust inhibitors in suppressing flame propagation and reducing the minimum ignition temperature of lignite dust explosion. The experimental findings reveal that ADP demonstrated a superiority of 18.33 % and 26.14 % over MCA in terms of flame propagation height and velocity at a concentration of 15 %, respectively. By comparing the inhibition effect of the two inhibitors on the minimum ignition temperature of lignite dust, ADP reached the abrupt concentration at 5 % and MCA was 10 %. Combined with thermogravimetric analysis, MCA primarily targets gas-phase reactions and exerts limited influence on the surface structure of lignite dust, resulting in suboptimal inhibition, ADP operates by generating minute quantities of inert gas and solid products, thereby exhibiting superior inhibitory effects than MCA. • Flame propagation of lignite dust was investigated with MCA and ADP. • Minimum ignition temperature of lignite dust was explored with MCA and ADP. • Thermogravimetric analysis of the MCA and ADP was given. • Suppression mechanisms of MCA and ADP for lignite were elucidated.