Innovative thermal process for high-purity group IV metal synthesis: Insights via DFT and MD simulations

The synthesis of group IV transition metals (TMs) such as Ti, Zr, and Hf from their respective oxides (TMO2) poses significant challenges with current methods. There is an urgent need for an environmentally friendly and versatile approach to establish sustainable, efficient, and adaptable TM synthesis technology from TMO2. In this study, the LN process (Lee-Nersisyan), a novel and straightforward approach that employs CaMg2 as the reductant for TMO2 powders is introduced. This innovative strategy involves the thermal processing of TMO2+kCaMg2 mixtures (with k values ranging from 2 to 5 moles) in an argon atmosphere at temperatures between 800 and 1200 °C. The process yields high-purity TM powder with particle sizes in the range of 5-25 μm and oxygen content of less than 0.2 wt%. We apply density-functional theory (DFT) to elucidate the interaction energies and equilibrium interatomic distances between Ti-Ca, Ti-Mg, Ca-Mg, Mg-Mg, Ca-Ca, and Ti-Ti metallic pairs. Additionally, we discuss the growth behavior of TM particles through molecular dynamics simulation (MD) employing LAMMPS. Our LN process represents a promising solution for efficient and sustainable TM synthesis from TMO2.