Recently, at the 125th Annual Meeting of the American Ceramic Society held in Columbus, Ohio, USA, the paper Phase Equilibria of MgO-Al2O3-TiO2 System at 1600 °C in Air: Emphasis on Pseudobrookite and Spinel Solid Solution Phases won the international academic award of “Spriggs Phase Equilibria Award of 2023”. The paper was published in the Journal of the American Ceramic Society with Associate Professor Shi Junjie from the School of Metallurgy of NEU as the corresponding author and his graduate student Qiu Yuchao as the first author.
Titanium-bearing blast-furnace slag is a by-product of vanadium titanium-magnetite blast furnace smelting. As its mass fraction of titanium-oxide in blast-furnace slag is more than 20%, it is an important secondary resource. To achieve efficient extraction of titanium from slag, it is necessary to clarify the process of high-temperature crystallization and mineral phase reconstruction of titanium-containing slag. At present, however, the basic data of phase equilibrium thermodynamics related to this are extremely scarce, resulting in the lack of targeted guidance for the development of efficient titanium resource extraction technology. Therefore, in view of the melting temperature, phase equilibrium relationship, composition of solid solution, occurrence valence state of titanium components and equivalent thermodynamic properties of occurrence in the CaO-SiO2-MgO-Al2O3-TiOx-MeOy (Me=Zr, P, Cr, etc.) Ti-containing multioxide system, the research team has studied for many years. The high-temperature equilibrium phase diagram of titanium-containing slag core oxide system has been established by combining the measurement of hot wire melting and crystallization properties, high-temperature phase equilibrium experiment and calculation phase diagram, which has filled the gap in the study of phase equilibrium thermodynamics in this field. Up to now, the research team has published a number of high-level academic papers in this field, and most of the research findings have been collected by the thermodynamics software Phase Equilibria Diagrams Version 5.0 of the American Ceramic Society. To tackle key problems, the research team joined hands with enterprises. In this award-winning paper, aiming at the deficiency of thermodynamic information of titanium-rich phase equilibrium in selective precipitation and crystallization process, they established the 1600°C isothermal cross section diagram of the core titanium-containing system of MgO-Al2O3-TiO2, and clarified the formation mechanism of plate titanite and spinel solid solution. Their research has provided key basic thermodynamic data for the extraction of titanium components from titanium-containing blast-furnace slag and the development of titanium-containing ceramic products.
The “Spriggs Phase Equilibria Award” was initiated by the American Ceramic Society, an authoritative international society in the field of ceramics, to reward the researchers making outstanding academic contributions to phase equilibrium thermodynamics. Only one research achievement in the world can be awarded this honor every year. Professor Li Jianzhong and Professor Liu Changsheng are the co-supervisors of this award-winning paper, and the other main participants include Hou Changle, Dong Jingjing, Zhai Yumo, etc. The research was co-funded by the China Postdoctoral Science Foundation, the Natural Science Foundation of Liaoning Province, and the Fundamental Research Funds for the Central Universities.