GB712179A - Improvements in and relating to the production of nitrogenous fertilisers - Google Patents

Abstract

A urea-aldehyde condensation product for use as a fertilizer, is made by heating a substantially anhydrous mixture of urea and paraformaldehyde, in the molar ratio of 1:1 to 2:1 and in the absence of condensation or buffer agents, at a temperature of 70 DEG to 120 DEG C. to form a slurry which is solidified by further application of heat or by cooling and is then broken up and dried. The slurry may be solidified in the reaction vessel by prolonged heating, but is preferably discharged and solidified on a chilled or heated metal roll or plate and broken up into flakes. Solidification may be accelerated by adding mineral acid, e.g. nitric acid, to the slurry in the reaction vessel prior to the discharge. The broken up solid product is dried preferably at 130 DEG C. or below and may be further crushed or powdered and granulated, e.g. by the addition of moisture and, if desired, other fertilizers such as ammonium sulphate, or an inert diluent such as anhydrite, gypsum, chalk, starch or plaster of Paris; the latter diluent may be added to the slurry in the reaction vessel. Specification 712,178 is referred to.ALSO:A fertilizer composition is made by granulating a urea-formaldehyde condensate (see Group IV(a)), preferably in a dried and crushed or powdered form, by the addition of moisture and other fertilizers, such as ammonium sulphate, or an inert diluent such as anhydrite, gypsum, plaster of Paris, chalk or starch. Specification 712,178 is referred to.