Thermal decomposition behavior and kinetics of rock-breaking incendiary agent based on peanut shell

In order to provide a theoretical basis for verifying the feasibility of partially replacement from the peanut shell to aluminum powder in the rock-breaking incendiary agent, its decomposition behavior was studied. A rock-breaking incendiary agent including peanut shell, aluminum and potassium nitrate was analyzed using DTA-TG and TG-FTIR experiments. An accurate kinetic model based on the analysis was proposed to describe the decomposition of the rock-breaking incendiary agent with peanut shell by applying an isoconversional method and non-linear regression to the TG data. We found that the thermal decomposition for the rock-breaking incendiary agent with peanut shell involves three reactions. Specifically, the peanut shell was pyrolyzed and then reacted with the potassium nitrate. After that, the newly generated coke from the peanut shell could be attended into the thermite reaction. The decomposition followed a 1.0738-th Prout–Tompkins equation with autocatalysis, with a differential kinetic mechanism function of f(α) = (1 − α)1.0738·α0.0888. Lastly, the thermodynamic parameters and theoretical volume of gas produced were studied. The self-accelerating decomposition temperature and the critical temperature of thermal runway were 882.50 K and 949.90 K, respectively. The theoretical volume of gas produced was 223.60 cm3 g−1, 2.64 times than that without peanut shell. These results show that the thermal stability of the rock-breaking incendiary agent with peanut shell is higher than that without peanut shell. In addition, adding peanut shell could be beneficial to improve the effect of breaking rock and reduce its costs.