Patent ID: 7498055

Claim:
Process for the preparation of urea granules in a fluid-bed granulator comprising the steps of: (a) feeding a film of a urea melt from at least one feeding device to a fluidized bed of solid urea nuclei, and (b) bringing the solid urea nuclei into contact with the film of the urea melt so as to cause the nuclei to grow by solidification of the urea melt thereon to form the urea granules, wherein the urea melt and the urea granules contain amounts of biuret and water which fulfill the following relation b m · b g w m · ( w m - w g ) = 0.1 - 20 wherein b m =the % by weight of biuret in the urea melt b g =the % by weight of biuret in the urea granules w m =the % by weight of water in the urea melt w g =the % by weight of water in the urea granules.