PREPARATION AND DSC OF PHASE STABILIZED AMMONIUM NITRATE CRYSTALLIZED FROM ITS AQUEOUS SOLUTION CONTAINING POTASSIUM FLUORIDE

DSC of crystallized ammonium nitrate prepared from its aqueous solution containing 1 wt% potassium fluoride heated from room temperature to 300 oC showed the disappearance of phase transformation normally appears at 32 oC. Phases appeared only at 91.6 oC, 122.76 oC and 162.82 oC even when the nitrate was stored under natural conditions for 75 days or exposed to heating at elevated temperature and cooling to room temperature for several times. Acceleration of the decomposition of ammonium nitrate containing potassium fluoride was recorded at a temperature earlier than the decomposition temperature of pure ammonium nitrate and characterized by many calorimetric values