Preparation of high-purity nickel by floating zone refining under a hydrogen atmosphere

Abstract

This study focuses on preparing high-purity nickel using floating zone refining under hydrogen atmosphere to overcome challenges related to impurity removal. The utilized high-vacuum floating zone refining device minimizes contamination and external impurities. The purification process's effectiveness is particularly notable for gaseous impurities, such as carbon and oxygen, with removal rates reaching 94.5% and 96.3%, respectively. The purification mechanism of the melt is considered as involving the nucleation and growth of hydrogen bubbles in the molten zone, and the adsorption of impurities on the bubble surface, followed by the ascent and overflow of bubbles, which effectively carry impurities out of the molten zone. © 2023 Elsevier Ltd