Ammonia → Ammonia

Participants

Reaction Steps

A process for producing solid ammonium phosphates in two stages which process comprises reacting in the liquid phase in a first stage phosphoric acid containing from 35 to 60% by weight of P2O5 and up to 20% by weight of H2SO4 at a pressure of from -0.1 to +1.5 kg/cm2 gauge with ammonia gas obtained from the ammonia-containing off-gases of the second stage of the process so as to produce a fluid ammonium phosphate product having an NH3 :H3PO4 molar ratio which varies from 0.1:1 to 1.45:1 and containing from 10 to 45% by weight of water; passing the said reaction product from the first stage to a second stage operating at higher pressure wherein the reaction product is reacted at a pressure of from 0.5 to 3.5 kg/cm2 gauge with ammonia gas to form a fluid ammonium phosphate having an NH3 :H3PO4 molar ratio of from 0.95:1 to 1.85:1 and a water content of from 4 to 20% by weight; discharging this fluid ammonium phosphate into a zone at lower pressure so as to produce a solid ammonium phosphate containing from 2 to 11% by weight of water: and recovering ammonia values from the off-gases of the said second stage of the process for use as the major source of ammonia gas in the first state of the process.

Provenance & Evidence