Thermodynamic Assessment of TiO2 Reduction to Ti Metal in Molten CaCl2

Abstract

Thermodynamic assessment of electrochemical reduction of TiO2 to Ti metal in CaCl2 molten salt electrolyte is discussed. The conversion of TiO2 to Ti takes place via multi-step reduction process that involves formation of several intermediates or sub-oxides of titanium at different reaction conditions. A complete understanding of these redox chemical reactions, and change in reaction Gibbs energy is very essential for efficient extraction of the Ti metal. This research article discusses the thermodynamic modelling studies on the formation of different titanium sub-oxides and corresponding reaction conditions (change in Gibb’s energy, temperature, and pressure) during TiO2 reduction to Ti metal.

Molten Salt Electrometallurgy

“…Also, the FFC Cambridge process could help lower the cradle-to-gate environmental impacts for Ti production by 3035% relative to the Kroll process [100]. Ti in the porous cathode can be addressed using TiCaOCl predominance diagrams [33,37] since they indicate thermodynamic effectiveness (i.e. high pO 2 > 6 and < 500 ppm oxygen in Ti at Ca activity aCa > 10 3 ) or severe diminishment (i.e.…”

Review—The Emerging Technologies for Producing Low-Cost Titanium

“…Figure 11a depicts the hydride-dehydride (HDH) process, which can produce Ti powder using Ti sponge, Ti mill products, or Ti scrap as the raw material. 86,87 The hydrogenation process is achieved utilizing a batch furnace that usually operates in a vacuum and/or atmospheric 79 hydrogen conditions. The hydrogenation conditions of titanium are the pressure of one atmospheric and temperatures of utmost 800 °C.…”

“…Low-cost production of titanium alloy powder can also be accomplished by a combination of one or more processes. 78,91,92,79 For instance, low-cost Ti-6Al-4V powder can be obtained via (i) one step melting of sponge/alloying and gas blowing alloy powder, (ii) metallothermic reduction of mixed chloride precursors to produce alloy powder, and (iii) electrolytic reduction in a fused salt of mixed alloying (TiCl 4 -AlCl 3 -VCl 4 ) chlorides. The demand to produce such low-cost titanium alloys is growing over the past few years for biomedical applications.…”

Molten Salt Electrometallurgy

“…Ti in the porous cathode can be addressed using TiCaOCl predominance diagrams[33,37] since they indicate thermodynamic effectiveness (i.e. high pO 2 > 6 and < 500 ppm oxygen in Ti at Ca activity aCa > 10 3 ) or severe diminishment (i.e.…”