Efficient separation and resource recovery of titanium powder and fluoride by-products from molten salt electrolysis of TiO2 assisted by aluminum salts

Electrochemical reduction of TiO 2 in NaF–K 2 TiF 6 -based molten salts offers a low-energy pathway for titanium production but generates fluoride-rich by-products (e.g., NaF, K 2 NaTiF 6 ), leading to contamination of titanium powder with hazardous species (F − , Na + , K + ). In this work, an aluminum salt-assisted selective leaching and co-precipitation method was developed to remove these impurities and recover valuable components. Key process parameters—including leaching temperature, leaching time, acid concentration, Al 3+ dosage, and liquid–solid ratio—were systematically optimized, achieving fluoride, sodium, and potassium removal efficiencies exceeding 95 %. The purified titanium exhibited significantly reduced fluoride residues. Meanwhile, the leachate was converted into high-purity anatase TiO 2 via hydrolysis and calcination, providing a potential feedstock for subsequent electrolysis. By-products such as Al 2 O 3 –AlF 3 mixtures, cryolite (Na 3 AlF 6 ), and Na 2 SO 4 were recovered from the filtrates. The residual leaching solution was recycled to establish a closed-loop process. This integrated separation and purification approach enables efficient decontamination, resource recovery, and sustainable management of fluoride-rich molten salt systems.