It is the most widespread process to produce ammonium nitrate with an average size up to 2.5mm.

The ammonium nitrate solution (ANS), at controlled concentration, temperature and pH is fed to the prilling sprayers located at the top of the prilling tower.
A filler can be added, if required, whenever the nitrogen content of the fertilizer needs to be reduced (e.g. CAN).
At the bottom of the tower, the prills are collected and discharged to a fluidized bed cooler. Then the material is screened in order to adjust the size distributions, before being coated to prevent caking and finally sent to storage.

Depending on environmental limits, the effluent gases from the prilling tower and/or the ANS film evaporator can also be treated in specially designed scrubbers to collect dust particles and submicron mist droplets

When bigger size distrubution and/or high solid matter needs to be included into the ANS, the AN based fertilizer Granulation process will be the preferable choice.