Effect of potassium chloride on thermal stability of ammonium nitrate under acidic conditions

Ammonium nitrate (AN) can decompose and further detonate under some conditions, e.g., in the presence of impurities which act as promoters. Its reactive hazards have been widely studied for several years. However, many large accidents involving AN still happened frequently in the recent years. It is found that, for accidents in storage or transportation, the thermal runaway is a major factor. The main objective of the research is to examine the effect of potassium chloride (KCl) on the thermal stability of AN under acidic conditions. The thermal stability of samples was investigated by differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), the Cook-off test and the Dewar test. The results indicate that KCl can significantly reduce the thermal stability of AN under acidic conditions. The catalytic effect of KCl on the decomposition of AN is limited without acidic conditions. The scale effect also is important factor to influence the thermal stability of AN.