SYNTHESIS OF NANOSILICA AND TiO₂ PRODUCTS FROM ILMENITE MUD THROUGH ALKALI ROASTING ROUTE

Ilmenite and rutile are major contributors to titanium dioxide production, depleting high-grade deposits in Ti production industries. In the present study, we investigate the possibility of using unreacted ilmenite mud as feed material for production of commercial TiO₂ production routes. Indian ilmenite mud generally consists of a rutile phase and is generally resistant to leaching. The alkali-assisted leaching process converts unreacted TiO₂ phases into easily leachable NaTiO₃ phases. Removal of silica, vanadium, and aluminium is performed as ternndite, vanadite, and aluminite, which yield valuable components for the whole process. In general, a huge quantity of ilmenite mud is dumped or stored near production sites, posing athreat to the environment. Ilmenite mud comprises valuable elements such as titanium, zirconium, and rare earth elements. Recovery and seperation are difficult due to their non-reactive nature with acids. In the present study, we designed an alkali-based process for the conversion of non-leachable TiO2 phases into easily leachable phases such as sodium titanate and sodium silicates. Byproducts such as silica and vanadium were important components for balancing the cost of production. The process involved the optimised removal of free acid through saline treatment, followed by roasting with sodium hydroxide to convert into easily leachable phases such as sodium silicates. The results of XRD, XRF, and SEM characterisation indicate that water-leached products contain 85% TiO2 content with low silica levels that can be used as the feed material in existing sulphate industries.