Ammonium nitrate density modification

Abstract From the Canadian patent

Ammonium Nitrato Density Modification, High density ammonium nitrate particle e.g. prilis are treated to reduce the density thereof by contact with a liquid medium which penetrates into the particles via preexisting pathways, dissolves ammonium nitrate at the surfaces of the pathways and produces a gassing reaction by virtue of the presence or a chemical gassing agent or by a reaction with the ammonium nitrate whereby a portion of the ammonium nitrate particle is depleted by dissolution or gas losses during reaction, the gassing action facilitating venting of liquid from the particles and drying thereof to yield a particle of higher porosity.