Sulfuric Acid → Phosphoric Acid

Participants

Reaction Steps

Concentrated sulfuric acid is added to the slurry as it enters the second tank. Monocalcium phosphate reacts with the sulfuric acid forming phosphoric acid and calcium sulfate hemihydrate. An excess of sulfuric acid will usually be used (see Table 4). A portion of the slurry is recycled back to the first tank where more pebble rock and recycle phosphoric acid are added. Another portion of the slurry is sent to the filtration stage. The first quantity of acid recovered is product acid containing from about 40% to about 47% P2O5. The solids from the slurry after filtration, are washed and the resulting filtrate containing about 30% P2O5 is recycled back to the first tank.

Provenance & Evidence