GB313652A - Improvements in the conversion of salts and more especially fertilizers and the likeinto globular or similar shaped bodies - Google Patents

Abstract

313,652. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). March 16, 1928. Drawings to Specification. Spray, freezing.-In the method of obtaining globular solid particles of salts, more particularly calcium nitrate or other fertilizer, by spraying the solution or melt in drops into a cooling liquid, the cooling liquid is rotated about a vertical axis within it so as to obtain a relatively long cooling path with a small quantity of the liquid. A fine powder such as chalk, gypsum, clay, talcum, kieselguhr, or magnesium silicate may be suspended in the cooling liquid so as to form a non- adhesive coating on the solidified particles, or a substance may be added which forms by reaction a protective film on the salts, for example barium hydroxide in the case of calcium nitrate melts. Alternatively or in addition to the powder, a paraffin or other oil or wax insoluble in water may be dissolved in the cooling-liquid. The melt may be fed through adjacently disposed nozzles, or be led on to an horizontal or slightly inclined rotating disc serving to direct the drops into the liquid, which by means of a stirrer or otherwise is given a paraboloidal rotating surface. Carbontetrachloride is mentioned as a suitable cooling liquid for a calcium nitrate melt containing 12.5 per cent of water, and 3 parts per 1000 of finely ground calcium carbonate may be added to the cooling liquid, with or without 3 parts of paraffin oil. Specification 233,720, [Class 82 (ii), Washing granular &c.], is referred to.