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.
Type:
Grant
Filed:
June 18, 1982
Date of Patent:
February 19, 1985
Assignee:
Compagnie Neerlandaise de l'Azote (Societe Anonyme)
Inventors:
Willy H. P. Van Hijfte, Luc A. Vanmarcke
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.
Type:
Grant
Filed:
April 20, 1978
Date of Patent:
April 24, 1979
Assignee:
Compagnie Neerlandaise de l'Azote (Societe Anonyme)
Inventors:
Willy H. P. Van Hijfte, Rafael A. J. Goethals, Anton Niks, Gerardus F. VAN DER Sijpt
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.
Type:
Grant
Filed:
June 29, 1977
Date of Patent:
October 31, 1978
Assignee:
Compagnie Neerlandaise de l'Azote (Societe Anonyme)
Inventors:
Willy H. P. Van Hijfte, Luc A. Vanmarcke, Anton Niks