UAN

UAN is a solution of urea and ammonium nitrate in water used as a fertilizer. The most commonly used grade of these fertilizer solutions is UAN 32.0.0 (32%N), which consists of 44.3% ammonium nitrate, 35.4% urea and only 20.4% water. Other grades are UAN 28, UAN 30, UAN 18. The solutions are quite corrosive towards mild steel (up to 500 MPY on C1010 steel) and are therefore usually equipped with a corrosion inhibitor to protect tanks, pipelines, nozzels, etc.

Physical and Chemical Characteristics of Urea Ammonium Nitrate Solutions

The solutions contain a remarkable low amount of water and nevertheless have a low salt-out temperature:

Physical and Chemical Characteristics of UAN Solutions

Grade, %N:	28	30	32
Ammonium Nitrate (%):	40.1	42.2	44.3
Urea (%):	30.0	32.7	35.4
Water (%):	29.9	25.1	20.3
Specific Gravity at 16°C:	1.283	1.303	1.320
Salt-out Temperature (°C):	-18	-10	-2