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: Manufacture of granules built up from a core and an envelope in a fluidized bed of nuclei. A stream of liquid containing the enveloping material is hydraulically sprayed within the bed from the bottom upwards by means of at least one hydraulic sprayer surrounded by a coaxial, annular, converging aperture through which auxiliary gas is discharged at such a vertical velocity that the conical stream of droplets is narrowed to a stream having an apex angle of less than 20.degree., and in such a quantity that a cavity of dilute fluidized phase is formed above each sprayer, which cavity is located entirely within the bed.

Abstract: Stabilized NH.sub.4 NO.sub.3 containing granules are produced by dissolving in an aqueous NH.sub.4 NO.sub.3 solution Mg(NO.sub.3).sub.2 and, if desired, suspending mineral filler, spraying the resulting solution or suspension over nuclei maintained in spaced interrelationship and contacted with a hot stream of gas at a temperature of the nuclei of between 120.degree. and 135.degree. C., and cooling the resulting granules in such a manner that, between 70.degree. C. and 50.degree. C., they remain substantially homogeneous in temperature.

Abstract: An apparatus for coating pellets, such as prills, granules and the like, with a liquid coating agent, which comprises a cylindrical, obliquely disposed drum arranged for rotation about its longitudinal axis, said drum comprising means at or adjacent its higher end for the supply and input of pellets to be coated and for supplying and spraying or atomizing said liquid coating agent over the pellets introduced, and means at or adjacent its lower end for the output and discharge of coated product pellets, and further is provided with partitions arranged transversely to the axis of rotation and dividing the drum into compartments, each of said partitions having a passage opening located eccentrically relative to the axis of rotation and so that the passage openings in each pair of partitions defining a compartment are peripherally offset relatively to each other.

Abstract: Urea granules are prepared by spraying an aqueous urea solution having a urea concentration of 70-99.9% by weight on to fluidized urea nuclei in the form of droplets having a mean drop diameter of 20-120 .mu.m at a temperature at which the water is evaporated from the solution sprayed on to the nuclei and urea crystallizes on the nuclei to form granules having a desired size.

Abstract: Urea bodies, such as crystals, prills, pellets and the like, with a reduced caking tendency are obtained by processing such bodies or a concentrated urea solution or melt produced in the urea synthesis, which is processed to form such bodies, with an aqueous solution containing an effective amount of dimethylol urea and/or trimethylol urea, which solution contains about 2 to about 5 mols bonded and free formaldehyde per mol of urea.

Abstract: Ammonium nitrate containing fertilizer pellets provided individually throughout their entire surface with a uniform and substantially closed coating of C.sub.12 -C.sub.18 alkylamine(s) in the solid state, and with a thin layer of mineral oil over said coating.

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.