Ammonia → Ammonia

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.

1. customthe said reaction product from the first stage to a second stage

ORD record

ord-9674eae73f994b228d70620035bfd1d5

Source dataset

uspto-grants-1976_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03974263