This invention describes a prilling apparatus for producing prills of ammonium nitrate or urea in which a diverging shroud extends from each prilling head. Means for supplying ammonia is connected to the shroud. The prills pass through a quiescent zone of ammonia in the shroud and the generation of fumes from the apparatus is surpressed. In addition the prills are coated with a layer of ammonia and are more readily cooled.
