Nitric acid is an important material for the production of explosives. Concentrated Nitric acid is usually mixed with Sulfuric acid (mixed acid) is used for Nitrating organic compounds. Nitration is a general class of chemical process for the introduction of a Nitro group into an organic chemical compound. Nitration reactions are notably used for the production of explosives for example conversion of guanidine to Nitroguanidine.
The waste acids come from Nitration and Esterification processes in the plastics and production of Energetic Material industries such as, for example the production of Nitrocellulose, Nitro glycerine, Di Nitro Toluene and Nitroglycol. The residues of these organic substances, and their intermediate products, and nitrous acid also have to be removed during the De Nitration. During De Nitration of Nitro Glycerine or Nitro Glycol waste acids the organic constituents are decomposed with the consumption of Nitric Acid and are passed to an NOx absorber as Nitrous gases.
Also refer:- Nitric Acid Concentration Plants & Sulfuric Acid Concentration Plants.