Insights on the role of KFCT in phase transition and thermal decomposition mechanism of ammonium nitrate

Abstract

AN-based products face challenges due to the phase transition at room temperature and structural instability. To better look into the thermal decomposition mechanism of AN, potassium ferrocyanide (KFCT) was selected as an additive to study its effect on the crystal form modulation and the thermal decomposition of AN. The results show that AN/KFCT co-crystal that does not undergo phase transition at room temperature was prepared. The thermal decomposition of AN/KFCT co-crystal is divided into three stages compared to that of pure AN. Thermal findings highlighted that Fe³⁺can reduce the thermal stability of AN. Co-crystallization enables Fe²⁺ to be encapsulated in crystals and therefore not oxidized during evaporative crystallization. Fe²⁺can inhibit the auto-catalytic process of AN by consuming auto-catalytic factor (NO₂). Furthermore, the TG-MS was used to study the thermal decomposition mechanism of AN/KFCT co-crystal. The thermal decomposition pathways of AN/KFCT co-crystal was clear constructed.