| abstract |
A method comprises: subjecting a NOx-containing process gas (22) to a NOx-absorbing step in a suitable absorption means (23), obtaining nitric acid (24), and a waste gas (25) containing nitrogen, argon and residual NOx; subjecting said waste gas (25) to a treatment which comprises at least one step of removing NOx, obtaining a conditioned waste gas (26); subjecting at least a portion (26b) of said conditioned waste gas to separation treatment, obtaining a product stream (40) containing argon and a product stream (37) containing nitrogen. |