Ammonia and Nitric Acid are fed to the Neutraliser, which can be operating under pressure, under vacuum or at atmospheric pressure. There is a high exothermic reaction which produces NH4NO3 and steam.
Ammonium Nitrate solution is then fed to an Evaporator and the resultant concentrated solution goes to the Prilling Tower.
NH4NO3 is entrained from both the Neutraliser and the Evaporator by the exiting steam, which can contain up to 15,000 mg/m3 ( or 4 kg/ton) of nitrate with an average size of 3 – 5 microns.
Air pollution.
Intermediate (NH4NO3 solution), & thus final, product loss
Note: In case of long shutdown periods, the Candle Filter fibre should be washed with water to prevent damage.