Modelling of Ti and Cl diffusivity in two TiCl₄ mediums for titanium production processes

Materials Modelling Centre, University of Limpopo, Private Bag X1106, Sovenga, 0727, South Africa

^* Corresponding author: andileZibu@gmail.com

Abstract

Titanium, a metal highly valued for its outstanding properties, is in increasing demand. The primary method for its production involves reducing titanium tetrachloride (TiCl4) with magnesium (Mg). However, this process is conducted batch-wise, making the development of a continuous reduction process challenging. Developing continuous reduction processes requires a detailed understanding of TiCl₄ behaviour, including diffusion and thermodynamic stability. Past modelling efforts have not provided an in-depth understanding of the diffusion behaviour of TiCl₄. While TiCl₄ has been studied computationally in ionic liquid systems, detailed atomistic insights remain limited. In this study, we employed the classical molecular dynamics DL_POLY code to investigate temperature effect on titanium (Ti) and chlorine (Cl) diffusion in the TiCl₄ medium. Analysis of the diffusion coefficients revealed a linear trend in the diffusion of Ti and Cl ions in the P12₁/c structure from 50 K to 2000 K, consistent with expected thermodynamic behaviour. These results shed light on how structural differences in TiCl4 influence ion mobility and stability, which can support accurate modelling of mass transport in TiCl4 under process-relevant conditions. Moreover, the findings provide valuable insights that can inform future refinements in titanium production processes.