Wettability of Ammonium Nitrate Prills

The wettability of ammonium nitrate (AN) prills is one of the primary factors determining the physical stability and detonation behavior of ANFO. The wettabilities of various types of AN prills were compared using capillary penetration measurements. Complementary characterization studies using scanning electron microscopy (SEM) and thermogravimetry (TG) were performed to rationalize the observed differences in wettability. The wettability of AN was found to be affected by several factors, including surface tension, viscosity, density, and purity of the liquid used, as well as surface composition, porosity, bulk density, particle size, moisture content, and thermal history of the AN samples.