Review—Progress in Research and Application of Molten Salt Electrolysis for Titanium Extraction
Jin Zhang, Hengwei Yan, Zhanwei Liu, Shenghui Guo, Yonghui Yang, Guang Yang, Rui Xia, Mingyi Hu, Landong Li
Abstract
Titanium (Ti), a metal known for its exceptional performance, is abundant in nature and holds significant potential for a variety of applications and advancements. However, the conventional Kroll process has faced criticism due to its high energy consumption, complex procedures, and environmental impact. In response, metallurgists worldwide are actively exploring innovative and sustainable methods for Ti production. Titanium metal production is generally classified into two main methods according to the specific raw materials and preparation methods employed: thermal reduction and molten-salt electrolysis. This paper provides a review of these two primary Ti production processes, comparing their respective advantages and suggesting potential areas for improvement and breakthroughs. In particular, we emphasize recent advancements in molten-salt electrolysis, such as the utilization of Ti-rich alloys as raw materials and liquid metals as cathodes. Notably, the advances in molten-salt electrolysis with liquid metal as cathodes show promise for the continuous production of high-purity Ti at reduced costs and energy consumption. We also introduce a novel approach: the preparation of Ti metal through double-chamber molten-salt electrolysis. Additionally, we explore future directions for enhancing the Ti metal production process.