A recyclable method for titanium extraction and oxygen evolution from Ti-bearing slags

Area of Science:

• Metallurgical Engineering
• Materials Science
• Electrochemistry

Background:

• The titanium industry faces challenges with high carbon emissions, production costs, and waste.
• Over 100 million tons of titanium-bearing blast furnace slag (TB-slag) are discarded in China.
• Efficient titanium extraction and recovery technologies are needed for TB-slag reutilization.

Purpose of the Study:

• To develop a low-cost, carbon-emission-free method for titanium extraction and oxygen evolution from TB-slag.
• To investigate efficient titanium recovery and metal refining processes.
• To establish a closed-loop system for sustainable titanium resource utilization.

Main Methods:

• Molten oxide electrolysis (MOE) with vacuum distillation.
• Analysis of binding energies and activities of liquid metal cathodes (Cu, Ni, Pb, Sn, Sb).
• Use of an Iridium (Ir) anode for molten oxide electrolysis.

Main Results:

• Antimony (Sb) demonstrated the best preferential deposition of titanium among tested liquid metal cathodes.
• Iridium (Ir) anode showed protective IrO2 formation, preventing corrosion in TB-slag.
• An alloy of titanium (Ti) and calcium (Ca) was obtained via MOE, with subsequent refining by vacuum distillation.
• A closed-loop process was achieved through a recyclable Sb cathode and continuous TB-slag feeding.

Conclusions:

• The developed MOE vacuum distillation method is simple, low-cost, and environmentally friendly.
• This process enables efficient utilization of titanium resources.
• The method contributes to achieving carbon neutrality in the titanium industry.