Patent ID: 6284212
Filing Date: 2001-09-04
Classification: C01B

Abstract:
In a process for treating an aqueous solution that at commencement of said process contains both nitric acid and sulfuric acid constitutes in predetermined amounts and that procures at conclusion of said process a greater amount of said nitric acid constituent than at commencement of said process, the improvement comprising:(a), preparing an initially consisted nitrosylsulfuric acid solution to constitute said aqueous solution at commencement of said process, by combining an aqueous nitric acid constituent with an aqueous sulfuric acid constituent, wherein the mole proportions of the nitric-sulfuric acid contents of said nitrosylsulfuric acid solution are from 0.1 M and up for the nitric acid content and from 6 about 10 M for the sulfuric acid content in order to ensure that said solution contains free water, nitrate ions, and nitrosyl ions;(b), treating said nitrosylsulfuric acid solution in accordance with a a next-defined step, viz. step (c), during solution confinement within a single reactor unit without solution transfer into and/or back and forth from any other reactor unit; and,(c), supplying to said nitrosylsulfuric acid solution within said single reactor unit free radicals of oxygen and nitric oxide that react with said nitrate and nitrosyl ions, by intimately contacting said solution with stoichiometric quantities of gaseous oxygen and gaseous nitric oxide, thereby forming in said solution, while binding free water, an amount of nitric acid constituent in excess of the amount of nitric acid constituent in said nitrosylsulfuric acid solution as initially consisted per step (a).