Urea prilling

The on-stream time is to be 330 days/year, and the product specification is fertiliser-grade urea prills containing not more than 1.0 per cent biuret. 

Prepare a mass balance diagram for the process, on a weight per hour basis, through to the production of urea prills. 

The fluidized dram granulation process had not been used before to produce granular AN. However, it had been used to fatten urea prills. Extensive pilot plant trials were carried out to define the parameters for granulating AN. The... 

Urea-ammonium nitrate solutions -Urea prills -... 

Fig. 5.2 Photograph of urea prills (courtesy Kaltenbach-Thurlng, Beauvais, France).

Stamicarbon bv Urea prills Urea melt Prilling technology producing low-cost, high-quality urea prills NA NA... 

Representative materials dried in direct-heat rotary dryers are sand, stone, ilmenite ore, sodium sulfate, sodium chloride, and fluorspar, for which high temperatures are used, cellulose acetate, sodium chloride, styrene, copperas, cast-iron borings, and ammonium sulfate, for which medium temperatures are required, and urea prills, vinyl resins, oxalic acid, urea crystals, and ammonium nitrate prills, that are dried at low temperatures [35]. 

A later paper gave a detailed description of a granulation plant that produces urea-ammonium phosphate OJAP) grades, such as 28-28-0, 22-22-11, 18-18-18, etc. [40]. The main raw materials are crushed urea prills, spray-dried ammonium phosphate (12-50-0), and potash salts. One unusual feature of the plant is a methylene-urea reactor, which is used for production of some NPK... 

Diammonium phosphate granular) Monoammonium phosphate (nongranular) Urea (prilled) ... 

Ibrahim, Y. A. 1992. "Product Quality Improvement on Urea Prills, Paper presented at the 1991 IFA Technical Conference, The Hague, Netherlands, October 6-8. 

Various attempts have been made to produce slow-acting nitrogen fertilisers. Reasonable results have been obtained with such products as resin- or polymer-coated granules of ammonium nitrate (26% N), sulphur-coated urea prills (36% N) (soil bacteria slowly break down the yellow sulphur in the soil), urea condensates and urea formaldehydes (30 0% N). At present these types of fertiliser are considered too expensive for farm cropping but are used in amenity and production horticulture. 

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