New Materials for Fluid Fertilizers
Balay, Hubert L.
Cole, Carl A. Jr.
Wright, Eugene B. Jr.
This material discusses new materials and approaches for fluid fertilizers, focusing primarily on nitrogen products, and briefly mentioning phosphate compounds. The paper highlights the shift from the direct application of aqua ammonia to anhydrous ammonia due to cost considerations. However, there is renewed interest in aqua ammonia solutions, particularly 41-percent nitrogen aqua ammonia, as a compromise between low-cost, non-pressure aqua and high-nitrogen anhydrous ammonia. The paper describes converting anhydrous ammonia to aqua ammonia using low-cost equipment and explores the benefits and considerations of using 41-percent nitrogen aqua ammonia. The authors also discuss utilizing heat of solution for dissolving urea in aqua ammonia. By leveraging the heat generated during mixing anhydrous ammonia and water, urea can be dissolved efficiently, and urea solutions can be used as direct application fertilizers or as supplementary nitrogen in mixed liquid fertilizers. Different methods and devices for dissolving urea are presented, including utilizing heat transfer in a heat exchanger or employing preheated water. Furthermore, the material discusses using fluid clay, specifically attapulgite-type clay, as a suspending agent in suspension fertilizers. The advantages of using predispersed fluid clay over dry clay are highlighted, such as easier handling, reduced dust, and improved product consistency. The production process for fluid clay is explained, along with considerations for preventing contamination from fertilizer salts. Finally, the authors describe how the plant used for producing nitrogen fluid clay can be modified to produce urea-ammonium nitrate (UAN) suspension fertilizers. The modifications involve incorporating a second centrifugal pump and a feedline to add ammonium nitrate to the dispersed clay slurry. The UAN suspension can serve as a supplemental nitrogen source in plants producing high nitrogen suspensions from base grades.
Nitrogen fertilizers, Phosphates, Urea