Skip to content
Surf Wiki
Save to docs
general/agricultural-chemicals

From Surf Wiki (app.surf) — the open knowledge base

UAN

Solution of urea and ammonium nitrate in water used as a fertilizer


Solution of urea and ammonium nitrate in water used as a fertilizer

UAN is a solution of urea and ammonium nitrate in water used as a fertilizer. The combination of urea and ammonium nitrate has an extremely low critical relative humidity (18% at 30 °C) and can therefore only be used in liquid fertilizers. The most commonly used grade of these fertilizer solutions is UAN 32.0.0 (32%N) known as UN32 or UN-32, which consists of 45% ammonium nitrate, 35% urea and only 20% water. Other grades are UAN 28, UAN 30 and UAN 18. The solutions are quite corrosive towards mild steel (up to 0.5 in per year on C1010 steel) and are therefore generally equipped with a corrosion inhibitor to protect tanks, pipelines, nozzles, etc. Urea–ammonium nitrate solutions should not be combined with calcium ammonium nitrate (CAN-17) or other solutions prepared from calcium nitrate. A thick, milky-white insoluble precipitate forms that may plug nozzles.

Physical and chemical characteristics of urea ammonium nitrate solutions

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

Grade, N%Ammonium nitrate (%):Urea (%):Water (%):Specific gravity at 16 °C:Salt-out temperature (°C):
283032
404245
303335
302520
1.2831.3031.320
-18-10-2

References

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

Want to explore this topic further?

Ask Mako anything about UAN — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report