Patent GB-937447-A (GB)
Title: Improvements in and relating to the pelleting of prillable chemical materials
IPC: C05C1/02
Filed: 1961-08-02
Abstract: Ammonium nitrate and caustic soda pellets are formed by bringing discrete molten quantities of the material into contact with an organic cooling liquid such as liquid halogenated aliphatic hydrocarbons for ammonium nitrate and unsubstituted hydrocarbons and unreactive halogenated hydrocarbons for caustic soda.  The cooling liquid must have a boiling point lower than the temperature of the molten material at the time of contact so that the liquid provides a vapour filled region between the pellets and the liquid until the pellets have assumed a quasispherical shape. Surface active agents can be added to the molten ammonium nitrate such as the condensation product of formaldehyde with the disodium salt of methylene dinaphthalene sulphonic acid and nonylphenol with ethylene oxide.ALSO:Urea pellets are formed by bringing discrete quantities of molten urea into contact with an organic cooling liquid such as a chlorinated aliphatic hydrocarbon or an unsubstituted aliphatic hydrocarbon, e.g. a petroleum fraction; the boiling point of the liquid must be lower than the temperature of the molten material at the time of contact so that the liquid around the material is vaporised to provide a vapor filled region between the pellets and the liquid until the pellets have assumed a quasi-spherical shape and then separating them from the liquid.ALSO:Ammonium nitrate and urea prills are formed by bringing discrete molten quantities of the material into contact with an organic cooling liquid such as carbon tetrachloride, trichloroethylene, perchloroethylene, tetrachloroethylene, chloroform, methylene chloride, methyl chloroform and other substituted methanes, ethanes and ethylenes in which hydrogen is replaced wholly or partly by bromine, fluorine or chlorine.  For pelleting urea petroleum fractions may be used. Surface active agents can be added to the molten ammonium nitrate such as the condensation product of, formaldehyde with the disodium salt of methylene dinaphthalene sulphonic acid, and nonyl phenol with ethylene oxide.  The boiling point of the liquid must be lower than the temperature of the molten material at the time of contact so that the liquid provides a vapour filled region between the pellets and the liquid until the pellets have assumed a quasi-spherical shape.ALSO:A process for pelleting ammonium nitrate, urea and sodium hydroxide comprises bringing discrete molten quantities of the material into contact with an organic cooling liquid in which the material is insoluble and the boiling point of which is lower than the temperature of the molten material at the time of contact so that the liquid around the material is vaporised to provide a vapour-filled region between the pellets and the liquid until the pellets have assumed a quasi-spherical shape and then separating them from the liquid.  The molten material may be dropped into the liquid or a jet of the material may be injected directly on to a moving stream of a cooling liquid, or into a container.  There are also examples describing the effects of different water content and additives in the pelleting material and various cooling liquids and jet sizes.