Original Article

Oxidation kinetics and crystal structure of high-titanium slag containing sodium salt

¹ College of Materials and Metallurgy, Guizhou University, Guiyang 550025, P.R. China
² Guizhou Province Key Laboratory of Metallurgical Engineering and Energy Process Saving, Guiyang 550025, P.R. China
³ Department of Materials Science & Engineering, University of Toronto, Toronto, ON, M5S 3E3, Canada
⁴ College of Materials Science and Engineering, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, P.R. China

^* e-mail: lvxiaodong115@126.com
^** e-mail: rhuang@gzu.edu.cn

Received: 28 September 2024
Accepted: 27 January 2025

Abstract

A novel technology was suggested to obtain the high-quality upgraded titanium raw materials for chlorination process through semi-molten states reduction with sodium salt and magnetic separation. The oxidation behavior and crystal structure of the obtained high-titanium slag containing sodium salt were studied. The Me₃O₅ solid solution is a uniform solid solution formed by doping Fe²⁺, Mg²⁺, and Mn²⁺ in the Ti ion occupancy sites based on the Ti₃O₅ component. Doping of these impurities cause a decrease in lattice volume, which induces the lattice to distort. As the oxidation progresses, the Me₃O₅ solid solution was oxidized to Anatase, and impurity elements such as Fe were doped into the Ti ion vacancies in Na_0.24TiO₂ to form sodium-titanium-iron oxide. Anatase was completely transformed into Rutile when the oxidation temperature increased to 900 °C, untransformed Anatase reacted with the sodium-titanium-iron oxide to form sodium-titanium oxide. At 550 °C, 600 °C, and 650 °C, the reaction was controlled by chemical reaction and gas diffusion, the apparent activation energy was 231.48 kJ/mol kJ/mol. At 650 °C, 700 °C, 800 °C, and 900 °C, the reaction is controlled by gas diffusion, the apparent activation energy was 6.52 kJ/mol.