Compound fertilizers prilling

Urea processes provide an aqueous solution containing 70—87% urea. This solution can be used directiy for nitrogen-fertilizer suspensions or solutions such as urea—ammonium nitrate solution, which has grown ia popularity recentiy (18). Urea solution can be concentrated by evaporation or crystallization for the preparation of granular compound fertilizers and other products. Concentrated urea is sohdified ia essentially pure form as prills, granules, flakes, or crystals. SoHd urea can be shipped, stored, distributed, and used mote economically than ia solution. Furthermore, ia the soHd form, urea is more stable and biuret formation less likely. 

The highest fixed nitrogen-containing fertilizer 46.7 wt %, urea is a white solid that is soluble in water and alcohol. It is usually sold in the form of crystals, prills, flakes, or granules. Urea is an active compound that reacts with many reagents. It forms adducts and clathrates with many... 

Fertilizer industry (chemical) Nitric acid acidulation Superphosphate storage and shipping Ammonium nitrate reactor Prilling tower NO, gaseous fluoride compounds Particulates (dust) nh3, no nh4, no3 Scrubber, addition of urea Exhaust system, cyclone or baghouse Scrubber Proper operation control, scrubbers... 

Urea, a highly water-solnble white crystalline compound, has by far the highest nitrogen content among solid fertilizer compounds (46.6%) as noted, its commercial synthesis was introduced by BASF in 1922 (fig. 7.1). Its good physical properties and lack of fire and explosion hazards make it the most commonly used solid nitrogen fertilizer, while liquid urea is commonly used in nitrogen solutions, and the prilled compound is a common part of mixed fertilizers. 

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