UAN
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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.