Methane explosion suppression characteristics based on the NaHCO₃/red-mud composite powders with core-shell structure

The NaHCO₃/red-mud (RM) composite powders were successfully prepared by the solvent-anti-solvent method for methane explosion suppression. The RM was used as a carrier, and the NaHCO₃ was used as a loaded inhibitor. The NaHCO₃/RM composite powders showed a special core-shell structure and excellent endothermic performance. The suppression properties of NaHCO₃/RM composite for 9.5% CH₄ explosion were tested in a 20L spherical explosion vessel and a 5L Perspex duct. The results showed that the NaHCO₃/RM composite powders displayed a much better suppression property than the pure RM or NaHCO₃ powders. The loading amount of NaHCO₃ has an intensive influence on the inhibition property of NaHCO₃/RM composite powders. The best loaded content of NaHCO₃ is 35%. It exhibited significant inhibitory effect that the explosion max-pressure declined 44.9%, the max-pressure rise rate declined 96.3% and the pressure peak time delayed 366.7%, respectively.