Nitric acid is widely used in manufacture of fertilizers, dyes, pharmaceuticals, ammonium nitrate, and other speciality organic nitro-derivatives. In most applications, nitric acid is required in the concentrated form.
The process of concentration of nitric acid involved pre-concentration of the acid by conventional method up to a concentration of approximately 68% by weight of nitric acid. Beyond this point, water and nitric acid form an azeotrope.
For further concentration, concentrated sulphuric acid (≈70%) is used. Nitric acid and sulphuric acid are entered into the column from separate ends and pass through a column of glass packing to give concentrated nitric acid as a result. The sulphuric acid becomes diluted and can be recovered using other methods.
Up to 99% nitric acid can be produced using this method. NOx gases, which leave the top of the column along with air, can be further treated to recover residual acid from them. A separate recovery unit can be provided here.
Ablaze can provide complete turnkey project for nitric acid concentration, right from basic engineering to detailed engineering, manufacture of equipment and finally installation.