Preparation and Flame-Retardant Mechanism of MgAlZn-Based Hydrotalcite-like Coal Spontaneous Combustion Inhibitor

In this work, the coprecipitation approach was successfully used to create Mg-Al hydrotalcite-like inhibitors modified with varying amounts of Zn, and their characteristics were assessed. The findings indicate that the flame retardancy of Mg-Al hydrotalcite (MgAl-LDHs) is not significantly affected by Zn content. By adding MgAl-LDHs, the temperature at which the exothermic reaction started to occur was raised from 146.2 °C to 193.6 °C, according to the test of spontaneous combustion tendency. In the excavation route, the utility model can serve as a temporary fire prevention and extinguishment tool. Furthermore, the analysis of the functional group changes during the reaction was conducted using FTIR. After applying MgAl-LDHs, the oxidation of organic groups on the coal surface was clearly prevented, indicating that the inhibitor had a substantial flame-retardant effect on coal. In conclusion, this work creates a material that resembles hydrotalcite and is easy to use, inexpensive, and effective in preventing coal from spontaneously combusting.