Features of metal products treatment in nitric acid

Reactions of metals with nitric acid have been studied for a long time and are widely used in technologies of chemical etching and polishing of products made of metals and alloys. High values of the redox potentials of nitric acid solutions allow to carry out the operations of the oxides film removal from the metal surface and to etch the products of complicated form made of electropositive metals and alloys on their basis. The purpose of the present work was the study of kinetics and mechanism of the process of copper dissolution in HNO₃ in wide concentration interval (4.0-14.8 M). Kinetics of interaction between copper and nitric acid has been investigated. The schema of the mechanism of this reaction has been offered. The schema of mutual transformations of products of nitric acid reduction in solution has been confirmed by the account of material balance on nitrogen.