In this study, rotating disk method was used to investigate the dissolution rate of metallic iron, nickel, and their alloys in nitric acid media. Used discs dia. 2 cm, made of nickel grade H1 and iron grade Armco, as well as two samples with Ni: Fe ratio of 15:85 and 50:50.The effect of temperature, initial nitric acid concentration, disk rotation rate and the process duration on the dissolution rate of the samples was investigated. The rate was determined by the amount of dissolved metal per unit time from the unit surface of the disk. A regression analysis was used to describe the effect of nitric acid concentration on the sample’s dissolution rate.It was found, that the dissolution rate of metallic iron is up to 20-60 times higher than the metallic nickel dissolution rate.When dissolving Ni and Fe alloys in nitric acid, the effect of temperature and initial concentration of HNO3 was inves- tigated. With temperature rise from 303 to 353 K ([HNO3] = 0.2 M, Ni:Fe = 50:50), the amount of dissolved Fe and Ni increased by 8-9 times.The dissolution of Ni:Fe alloy (15:85) at the same conditions resulted in an increase in dissolved iron and nickel by 4 times. An increase in the concentration of nickel in the solution occurs within 30 minutes, after which the concentration does not change. In experiments with Ni:Fe alloy = 50:50 the amount of dissolved Fe is 1.8-2.3 times more than the amount of dissolved Ni, depending on the initial acidity.
Level of Research Output
- VAK List
- Russian Science Citation Index