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:
| 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 |