Mixed acid

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.

Spillage may cause fire or liberate danger-ous gas. Causes severe burns, irritant by ingestionand inhalation, may cause Noxpoisoning.

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:P₂O₅ ratio. The mixed acid route covers a range of formulations with the nitrogen to phosphorus (N:P₂O₅) ratio ranging between0.5 and 2.0.