Kinetics and Dissolution Mechanism of an Alloy (90%Cu10%Ni) in a Concentrated Solution of Lithium Bromide

This paper examines the dissolution process of the alloy (90%Cu 10%Ni) in a solution of 50 wt% (11.8 molal) lithium bromide (LiBr) under real operation conditions using the following electrochemical techniques: polarization curves, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), and electrochemical noise (EN). The importance of the cuprous bromide (CuBr) film in the alloy dissolution process is determined, as well as the role played by the chemical reaction in such dissolution. Here, the behavior of the cell at 45°C in dynamic conditions is analyzed. In these conditions, the film dissolution process is slower, causing the development of a pitting corrosion process. The rate constants are determined, noting that they correspond fairly well to the behavior of the system. The alloy dissolution rate is determined using LPR and EIS. In this regard, both techniques reported very similar results. A kinetically easy reaction in which mass transfer acquires a leading role is the result presented in this analysis.