Abstract: A classifying fluid bed granulator includes a granulation chamber including a fluidizing air chamber (7) with a bed floor (10), a ceiling (3c), an end wall (3d), and a feed inlet (5), a seed inlet (6), an air outlet (4) defined by walls (3a, 3b) and an outlet (9) for produced granules. The granulation chamber is divided into an agglomeration and seed control section (1) and a granulation and classification section (2), and the section (2) includes one or more consecutive compartments having an asymmetric design.

Abstract: The present invention relates to a classifying fluid bed granulator, comprising a granulation chamber with a fluidizing air chamber (7) with a bed floor (10), a ceiling (3c), an end wall (3d), a feed inlet (5), a seed inlet (6), an outlet (4) defined by walls (3a, 3b) for air, and an outlet (9) for produced granules. The granulation chamber is divided into an agglomeration and seed control section (1) and a granulation and classification section (2) where said section (2) is divided into two or more consecutive compartments having an asymmetric design. Section (2) may contain tilted baffle plates (12). Furthermore, the present invention relates to a method for fluid bed granulation of a feed being a solution, slurry, melt, emulsion, suspension or solids into granules of a desired classified size. Inlet seed particles are given a controlled size in an agglomeration and seed section ahead of being granulated with the feed in a granulation and classification section.

Abstract: The invention concerns a method of producing fertilizer granules containing urea and ammonium sulphate by granulating a mixture containing urea, ammonium sulphate and water, which is characterized in that the ammonium sulphate is completely dissolved in an aqueous urea solution with a urea concentration of 70-85% by weight, the resulting solution is thickened to a dry content of 92-97% by weight, with a granulation additive for the urea being added in any stage of the treatment, following which the thickened solution is granulated in a fluidized bed of urea and ammonium sulphate containing nuclei.

Abstract: The production of urea granules by prilling or granulating a urea melt or an aqueous urea solution, which melt or solution contains a magnesium oxide containing additive. The urea granules thus obtained exhibit a high crushing strength, a high apparent density, and a very low caking tendency, and are suitable for bulk blending with single and triple superphosphate granules.

Abstract: A process for making granules containing urea as the main component by prilling or granulating a urea melt or an aqueous urea solution, which melt or solution may contain one or more other fertilizers, such as ammonium sulphate, ammonium dihydrogen phosphate and diammonium hydrogen phosphate, in solution and/or suspension. According to the invention, a water-soluble aluminum salt is added to the melt, solution or suspension to be prilled or granulated. Preferably the aluminum salt is added in a quantity equivalent to at least 0.1% by weight of Al.sub.2 O.sub.3, calculated on the solid content of the melt, solution or suspension.

Abstract: A process for making granules containing urea as the main component by spraying an aqueous urea solution having a urea concentration of 85-98% by weight, to which solution magnesium hydroxide, an inorganic magnesium salt or a mixture of such substances has been added as a crystallization retarder for the urea, and which solution optionally contains one or more other fertilizers in solution and/or suspension, is sprayed in the form of very fine droplets having an average diameter of between 20 and 120 micron into a fluidized bed of urea particles at a temperature at which the water on the solutions sprayed onto the particles is evaporated, and urea or urea containing material solidifies on the particles, to form granules having a desired size. The urea granules thus produced are compatible with single and triple superphosphate granules.

Abstract: Preparation of ureaform granules. A concentrated aqueous solution of a urea-formaldehyde condensate is mixed with a catalyst which at normal temperature effects virtually no acid condensation, but a elevated temperature releases sufficient strong acid to effect the acid condensation in a few seconds. The mixture of solution and catalyst is sprayed over solid ureaform particles maintained in spaced interrelationship and at such a temperature that the catalyst is decomposed and effects acid condensation, whereby the sprayed particles are coated with a layer of ureaform and dried.