Patent GB-828881-A (GB)
Title: Fertilizers
IPC: C05B1/02
Filed: 1955-11-28
Abstract: A phosphatic fertilizer is manufactured by mixing an inorganic acid material and phosphate rock and after the mass has hardened to such an extent as to be disintegrable without coalescing, by breaking up the mass, subsequent further hardening as well as curing of the broken-up mass taking place, and by thereafter curing the mass at normal pressure and obtaining a sensibly dry free-flowing cured fertilizer product, wherein, from the time the mass is broken up to the practical completion of curing, (a) substantially no evaporation of the water content of the mass takes place and cooling goes on substantially continuously, and (b) the water content of the mass undergoing curing is such that there results a sensibly dry freeflowing fertilizer product which has been dried substantially entirely by crystallization alone. The acid may be sulphuric or phosphoric acid or a mixture thereof, or a preponderantly dry acidic sludge as described in Specification 828,883.  Phosphate rock high in iron and/or aluminium or like metals may be utilized.  Additional fertilizer ingredients such as nitrogeneous material (ammonium sulphate or nitrate or urea), a potassium salt (potash, or potassium sulphate, nitrate, or chloride), or another metal salt (e.g. a salt of iron, aluminium, manganese, zinc, copper, magnesium, barium, strontium, chromium, cobalt or nickel) may be added to the initial reaction material or to the mass as it is being broken up or immediately thereafter.  The reaction mass may be allowed to harden in a den with a stationary or movable floor.  The broken-up mass is placed in a storage space provided with a number of spaced vertical metal pipes about which the material is piled in relatively thin successive layers, and when the material is hardened sufficiently to hold its form the pipes may be moved upwardly, thus producing air passages leading into the pile formed in part by the material itself and in part by the pipes.  The process may be repeated until the pipes are finally removed.  The broken-up material may also be deposited about similar but fixed pipes installed in cars. It is stated that the fertilizer obtained contains a substance responding to tests for calcium hypophosphite.  Phosphoric acid may be substituted for all or part of the sulphuric acid to produce enriched or triple superphosphate.  An example is given illustrating the process.  Specification 828,882 also is referred to.ALSO:A phosphatic fertilizer is manufactured by mixing an inorganic acid material and phosphate rock and after the mass has hardened to such an extent as to be disintegrable without coalescing, by breaking up the mass, subsequent further hardening as well as curing of the broken-up mass taking place, and by thereafter curing the mass at normal pressure and obtaining a sensibly dry free-flowing cured fertilizer product wherein, from the time the mass is broken up to the practical completion of curing, (a) substantially no evaporation of the water content of the mass takes place and cooling goes on substantially continuously, and (b) the water content of the mass undergoing curing is such that there results a sensibly dry free-flowing fertilizer product which has been dried substantially entirely by crystallization alone. The acid may be sulphuric or phosphoric acid or a mixture thereof, or a preponderantly dry acidic sludge as described in Specification 828,883.  Phosphate rock high in iron and/or aluminium or like metals may be utilised.  Additional fertilizer ingredients such as nitrogeneous material (ammonium sulphate or nitrate or urea), a potassium salt (potash, or potassium sulphate, nitrate, or chloride), or another metal salt (e.g. a salt of iron, aluminium, manganese, zinc, copper, magnesium, barium, strontium, chromium, cobalt or nickel) may be added to the initial reaction material or to the mass as it is being broken up or immediately thereafter.  The reaction mass may be allowed to harden in a den with a stationary or movable floor.  The broken-up mass is placed in a storage space provided with a number of spaced vertical metal pipes about which the material is piled in relatively thin successive layers, and when the material is hardened sufficiently to hold its form the pipes may be moved upwardly, thus producing air passages leading into the pile formed in part by the material itself and in part by the pipes.  The process may be repeated until the pipes are finally removed.  The broken-up material may also be deposited about similar but fixed pipes installed in cars. It is stated that the fertilizer obtained contains a substance responding to tests for calcium hypophosphite.  Phosphoric acid may be substituted for all or part of the sulphuric acid to produce enriched or triple superphosphate.  An example is given illustrating the process.  Specification 828,882 also is referred to.