Minol IV, A New Explosive Composition Containing Ammonium Nitrate-Potassium Nitrate Solid Solution. Part 1

Minol II 40 ammonium nitrate, 20 aluminum is useful as an explosive fill for bombs, because its use substitutes cheap, and abundant, ammonium nitrate AN for more expensive, and sometimes scarce, TNT. However, Minol II exhibits poor dimensional stability when exposed to temperature cycles during storage. It has been shown that growth of Minol II charges during temperature cycling is caused by the polymorphic phase transition which occurs in AN above 32C. Review of the literature suggested that this phase transition could be prevented by substitution of a solid solution of potassium nitrate KN in AN for AN in explosive compositions. Some of the reported properties of such solid solutions KN-AN-III or AN-KN have been confirmed. Charges containing 40 TNT, 40 AN-KN and 20 aluminum now designated Minol IV showed better dimensional stability during temperature cycling than either TNT or TNT aluminum 6733.