| 摘要 |
<p>Urea is reacted directly with impure wet process phosphoric acid (30-60% P2O5) to give crystalline urea phosphate and a mother liquor contg. all the impurities and the urea phosphate is treated with ammonia under at least atm. press. to give slightly polymerised ammonium polyphosphate (non-ortho P2O5 is at least 50% of total P2O5), the two stages being effected without the use of heat, the system being autothermal and conducted with a positive heat balance. The product may be in liquid or solid form. The mother liquors may be ammoniated to give an ammonium phosphate-urea fertilizer. The product of the process contains ammonium pyrophosphates is stable and very sol. in water.</p> |
