Study on explosion suppression and gas ablation of CuO−CeO₂/CaO composite powders with catalytic adsorption

Coal mine gas explosion accident will not only produce a huge shock wave, but also produce a large number of toxic and harmful gas CO, which seriously affects the mine safety production environment. In order to achieve the dual protection of explosion suppression and gas ablation, CuO−CeO₂ composite oxide was used as CO catalyst and CaO was used as CO₂ adsorbent. The catalytic adsorption composite powder CuO−CeO₂/CaO doped with CaO was prepared by the combination of solid phase impregnation and thermal dispersion. The effects of H₂O and CaO doping amount on the catalytic adsorption performance were investigated by heating and isothermal gas reaction experiments. The physical and chemical structures of CuO−CeO₂/CaO were characterized by X-ray diffractometer, X-ray photoelectron spectrometer, Raman spectrometer and scanning electron microscope. The explosion suppression and gas ablation properties of different powders were analyzed by 20 L spherical explosion tester and gas chromatograph. The results show that the doping of CaO reduces the negative effects of H₂O and CO₂ on CuO−CeO₂/CaO, promotes the formation of surface oxygen vacancies and the interaction between Cu−Ce, and then improves the CO catalytic performance, so that it can completely oxidize CO at about 120 ℃. When the doping amount of CaO is 15%, its CO catalytic performance and CO₂ adsorption are the highest. Compared with equal mass Al₂O₃ and CuO−CeO₂ powders, CuO−CeO₂/CaO composite powders have stronger explosion suppression and gas ablation ability. The specific performance is that after adding CuO−CeO₂/CaO, the maximum explosion pressure, maximum pressure rise rate and deflagration index of gas explosion reach the lowest, which are 0.483 MPa, 7.60 MPa/s and 2.1 MPa·m/s, respectively, and the elimination rates of CO and CO₂ reach the highest, which are 89.1% and 95.3%, respectively. The study confirmed that the composite powder CuO−CeO₂/CaO can eliminate CO and CO₂ by its catalytic adsorption, and reduce the gas explosion pressure by interrupting the chain reaction, dilution asphyxiation and endothermic effect of adsorption products, which provides a new idea for reducing the risk of gas explosion.