Dissolution of zero-valent Al and its structural transformation in chloride molten salts

Abstract

Molten salts are extensively used in the aluminum production and recycling industries. In this study, we discovered that metallic Al can directly dissolve into molten salts in its zero-valent state, forming nanoclusters—an unusual phenomenon as metals typically dissolve in molten salts in various oxidation states due to corrosion. The dissolved Al can gradually oxidize due to water or oxygen impurities during its diffusion within the molten salts. We thoroughly investigated the interactions between Al and molten salts and analyzed the structure of the reaction products using HT-NMR methods. These findings provide a novel explanation of the interactions and corrosion processes between metals and molten salts.