Theoretical and Experimental Study of the Reaction between Ammonium Nitrate and Sodium Salts

Hazards posed by chemical incompatibility, especially in a large-scale industrial environment, warrant a deeper understanding of the mechanisms of the reactions involved in these phenomena. In this study, reactions between ammonium nitrate and two sodium salts, namely, sodium nitrate and sodium nitrite, have been studied by ab initio calculations (with density functional theory, DFT) and experimental calorimetric methods (with differential scanning calorimetry, DSC, and heat flux calorimetry, HFC). The agreement between theoretical and experimental results allows an understanding of the thermal decomposition behaviors of the two sodium salts when exposed to ammonium nitrate. Moreover, this study highlighted the critical role of the water that appears to promote the incompatibility between ammonium nitrate and sodium nitrite.