Definition
A mixture of sulfu-ric and nitric acids used for nitrating, e.g., in themanufacture of explosives, plastics, etc. Consists of36% nitric acid and 61% sulfuric acid.
Hazard
Spillage may cause fire or liberate danger-ous gas. Causes severe burns, irritant by ingestionand inhalation, may cause Noxpoisoning.
Agricultural Uses
Mixed acid is a mixture of sulphuric acid (61 %) and nitric
acid (36 %) used for nitration.
Mixed acid process for nitrophosphate
production
There are two processes used for making nitrophosphate
fertilizers - the Odda process and the mixed acid
process.
Ammonium phosphate nitrate (APN), nitric
phosphates and ammonium nitrophosphates are
nitrophosphate fertilizers produced by reacting
phosphate rock with nitric acid.
In the mixed acid process, calcium nitrate does not
precipitate and separate. The water-solubility of
phosphate is increased by adding phosphoric acid to
decrease the CaO:P
2O
5 ratio. The mixed acid route
covers a range of formulations with the nitrogen to phosphorus (N:P
2O
5) ratio ranging between0.5 and 2.0.
