| 摘要 |
1,138,063. Ammonium nitrate, ammonium phosphate mixture. FISONS FERTILIZERS Ltd. 19 July, 1966 [13 Aug., 1965], No. 34852/65. Heading C1A. A mixture of ammonium phosphate and ammonium nitrate containing less than 5% by weight of water, is produced by feeding into a medium ammonia gas and at least two compounds from a group consisting of nitric acid, phosphoric acid, ammonium nitrate and ammonium phosphate, the selection being made so as to provide at least one acid component, one nitrate-containing component and one phosphate - containing component, the medium comprising previously formed reaction product containing 2% to 10% by weight of water, held at its boiling-point by the heat of reaction and having a pH in the range 2À0 to 2À8. Part of this medium is removed and reacted with a counter-current of ammonia or a mixture of ammonia and an inert gas at a temperature in the range 140‹ C. to 190‹ C., reducing the water content to less than 5% and giving a product having a pH in the range 3À0 to 6À0. The acids fed to the medium are preferably a 40% to 80% by weight nitric acid solution, and a 30% to 60% by weight of phosphorous pentoxide, phosphoric acid solution. These acids may be heated to 20-100‹ C. before being fed to the medium. Concentrated sulphuric acid may also be fed to the medium. The reaction with a counter-current of ammonia may take place in a tower reactor. Granular fertilizers may be obtained from the mixture of ammonium phosphate and nitrate. |
