Metal Dissolution Kinetics in Halide Melts

摘要

Although the kinetics and mechanism of the anodic dissolution of metals is an important aspect of corrosion studies, few such measurements have been carried out in high-temperature molten salts, mainly because of experimental difficulties caused by the high temperature and the high rate of the reactions. In this work the dissolution kinetics of nickel, iron, and molybdenum has been investigated in several halide melts. These melts were the eutectic mixtures of LiCl-KCl, LiCl-RbCl-CaCl sub 2 , LiBr-KBr-CsBr, and NaCl-NaAlCl sub 4 , containing 10 exp -7 to 10 exp -4 mol cm exp -3 chloride of the metal under investigation. The measurements were carried out in the temperature range of 175 to 550 exp 0 C. The measurement techniques used were D.C. relaxation techniques, mainly double pulse galvanostatic, but also single pulse galvanostatic, and coulostatic techniques. The results of these measurements will be presented, compared to previously reported exchange current densities, and discussed in the light of the applicability limitations of each measurement technique for fast reactions. (ERA citation 09:020562)