Patent GB-911067-A (GB)
Title: Manufacture of granular materials
Inventor: BROOK ALEXANDER TURNER
IPC: B01J2/12
Filed: 1957-11-20
Abstract: Pulverulent materials are granulated by injection of steam, at a velocity of 20 to 110 ft./sec., below the level of the material, the wetted material being agitated to granulate and thereafter dried, e.g. in a rotary drier.  Materials that may be granulated are superphosphates with or without other fertilizer ingredients such as ammonium salts, e.g. ammonium sulphate, ammonium nitrate, ammonium sulphate-nitrate mixture and ammonium phosphate, and/or potassium salts, e.g. potassium chloride, and/or nitrogeneous materials, e.g. urea, salts of urea, urea-formaldehyde resins. The material to be granulated may also comprise any fertilizer salt or compound either alone or admixed together with or without diluents such as gypsum, brick dust, adsorbent earths, chalk. Calcareous materials, e.g. limestone, mail, chalk, argillaceous materials, e.g. iron ore, gypsum, basic slag, alumina, silica, catalytic materials, aluminium-ferric oxide compositions and mixtures of any of these materials, may also be granulated.  The steam is injected through a nozzle, for example, a fish-tail nozzle in which the plane of the outlet orifice is parallel to and facing the wall of the drum. Reference has been directed to the Comptroller to Specification 794,030.ALSO:Fertilizers are granulated by treatment with steam introduced at a point below the level of the solid material in the wetting zone and having a velocity of 20-110 ft./sec., the wetted material being agitated to granulate and then dried, e.g. in a rotary drier.  The fertilizer materials to be granulated may comprise superphosphates with or without other fertilizer ingredients such as ammonium salts, e.g. ammonium sulphate, ammonium nitrate, ammonium sulphate-nitrate mixture and ammonium phosphate, and/or potassium salts e.g. potassium chloride, and/or nitrogeneous materials e.g. urea, salts of urea, urea-formaldehyde resins.  Any fertilizer salt or compound either alone or admixed together with or without diluents such as gypsum, brick dust, adsorbent earths, chalk, may also be granulated.  The granulator used may comprise any of those previously used for fertilizers involving the use of water; however, according to a preferred embodiment of the invention, the granulation is effected as a continuous process in a rotating steel drum, which may be provided with a baffle and which may be inclined to the horizontal, to which the material to be granulated is supplied and where it is treated with steam and the wetted material removed and dried in a rotary drier. Preferably a modified fish-tail nozzle in which the plane of the outlet orifice, is parallel to and facing the wall of the drum is used for the injection of the steam.  Reference has been directed by the Comptroller to Specification 794,030.ALSO:Metal ores such as iron ore are granulated by injection of steam, at a velocity of 20 to 110 ft/sec., below the level of the material, the wetted material being agitated to granulate and thereafter dried e.g. in a rotary drier.  The steam may be introduced through a modified fish-tail nozzle in which the plane of the outlet orifice is parallel to and facing the wall of the drum.  According to a preferred embodiment, granulation is effected as a continuous process in a rotating drum which may be provided with a baffle and which may be inclined.  The wetted material is removed and dried in a rotary drier.  Reference has been directed by the Comptroller to Specification 794,030.