| 摘要 |
<p>1,257,499. Ammonium phosphate. GULF RESEARCH & DEVELOPMENT CO. 21 April, 1969 [25 April, 1968], No. 20161/69. Heading C1A. Ammonium phosphate is separated from an ammonium phosphate-ammonium nitrate mixture, suitably that obtained from a sulphate cycle nitrophosphate process, by a process which comprises heating an aqueous slurry of the mixture to a temperature below boiling, and crystallizing, separating and recovering the solid product, which has a NH 3 to H 3 PO 4 mole ratio of between 1À1 : 1 and 2À0 : 1, from the reaction mixture. In the slurry, the concentration of water at the highest and lowest operating temperatures is maintained between the limits of 5% and 35% by weight respectively, and the nitrate ion concentration to water content weight ratio between 7 : 1 and 1À3 :1, respectively. In addition to the ammonium nitrate present in the slurry, the concentration of ammonium and phosphate ions is so maintained that there is sufficient additional ammonium ions to maintain the concentration of ammonium phosphate within one of three sets of predetermined (defined) limits. Additional product may also be obtained by cooling the filtrate from the above process and crystallizing from the filtrate a solid containing 90-97% ammonium nitrate and 3-10% ammonium phosphate. If it is desired to make the process continuous, the starting slurry may be formed with at least a portion of the liquid filtrate from the last-mentioned crystallization, the water content of which may be controlled by evaporation.</p> |
