## 3 Results and Discussion
### Analysis of Explosion Residues
The XRF analysis of the solid products showed that before adding the 20% MSA-NaHCO3 composite powder explosion inhibitor, the mixed dust was primarily composed of SiO2, Fe2O3, Al2O3, and CaO. After adding the mixed dust explosion inhibitor, the Fe2O3 and Al2O3 contents in the gas products were slightly increased. The pyrolysis endothermic effect of metal hydroxides in the inhibitor, such as Al(OH)3 and Fe(OH)3, gave rise to metal oxides such as Al2O3 and Fe2O3, thus adding to the Fe2O3 and Al2O3 contents. In order to study the chemical reaction forms in the process of the explosion, the types of functional groups in the pre-explosion and post-explosion dust samples were tested using a Vertex70 Fourier transform infrared spectrometer (FTIR) (Bruker). The 400-4000 cm\({}^{-1}\) waveband of the infrared spectrum was selected [32]. Figure 13 shows the FTIR analysis results of the suppression behavior of the MSA-NaHCO3 composite powder explosion inhibitors on industrial dust explosions. The FTIR analysis results indicate that, after MSA-NaHCO3 composite powder explosion inhibitor was added, the explosion residue of the oil shale dust contained a C = O stretching vibration of carboxyl group near 1600 cm\({}^{-1}\) in all cases. After the explosion, the vibration peak intensity reduced and the stretching vibration of the carboxyl group occurred near 3500 cm\({}^{-1}\). The vibration peak intensity increased a little after the explosion because NaHCO3 participated in the reaction during the explosion and were decomposed into NaOH, CO2, and H2O. The CO2 and H2O were evaporated; the C=O of the carboxyl group reduced and the carboxyl increased. In the process of explosion suppression, \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multirow{2}{*}{**Sample**} & \multicolumn{8}{c}{**Relative Content**} \\ \cline{3-10}  & & **CO2** & **NO2** & **CO** & **SO2** & & & & \\ \cline{2-10}
**Analysis** & **100\% Oil Shale** & **73.5** & **2.2** & **3.4** & **0.23** & & & & \\ \cline{2-10}  & **20\% MSA–NaHCO3 and Oil Shale** & **78.7** & **1.3** & **5.6** & **0.11** & & & & \\ \hline \multirow{4}{*}{XRF analysis} & \multirow{4}{*}{20\% MSA–NaHCO3 and oil shale (before explosion)} & SiO2 & Fe2O3 & Al2O3 & CaO & Na2O & TiO2 & MgO & MnO \\  & & & & & & & & & \\ \cline{1-1}  & & & & & & & & & \\ \cline{1-1}  & & & & & & & & & \\ \cline{1-1}  & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Composition analysis of explosion products. the MSA-NaHCO\({}_{3}\) composite powder explosion inhibitor generated gas, which competed for space with oxygen in a limited space and helped reduce the oxygen concentration in the explosion environment, known as the gas inerting effect. Meanwhile, in order to study the explosion suppression mechanism of the MSA-NaHCO\({}_{3}\) composite powder explosion inhibitor, the explosion suppression mode was thermogravimetrically analyzed. MSA, NaHCO\({}_{3}\), and MSA-NaHCO\({}_{3}\) composite powder explosion inhibitors, as well as oil shale dust, were thermogravimetrically analyzed using an STA PT 1600 simultaneous thermogravimetric analyzer (TGA) across a temperature range from room temperature to 800 \({}^{\circ}\)C increased at an interval of 10 \({}^{\circ}\)C/min. The results are presented below. Figure 14a shows the TG-DSC curve of MSA, which shows that 50-120 \({}^{\circ}\)C was the endothermic decomposition of H\({}_{2}\)O in MSA and 200-600 \({}^{\circ}\)C was the endothermic pyrolysis of Al(OH)\({}_{3}\), Fe(OH)\({}_{3}\), and other metal hydroxides in MSA when forming metal oxides such as Al\({}_{2}\)O\({}_{3}\) and Fe\({}_{2}\)O\({}_{3}\). Figure 14b shows the TG-DSC curve of NaHCO\({}_{3}\).