Alkali Roasting of Titania Slag for Preparation of High Grade -TiO2Author(s): Salah A Zaki
A high grade TiO2 product of 99.1% purity has successfully been prepared from the Egyptian Rosetta titania slag by its proper roasting with sodium hydroxide. The reaction product was then successively washed by water followed by controlled HCl acid leaching procedures in order not to dissolve the titanium values. The first step has aimed to dissolve silica, alumina besides possible V and Cr as well as recovering the excess NaOH while the HCl acid leaching step was so applied to selectively dissolve the iron and other impurities. The studied optimum conditions of roasting involved a slag/NaOH ratio of 5/6 at a roasting temperature of 850°C for 0.5 h. After both leaching circuits the titanium product left behind was filtered and properly washed with distilled water before drying at 110°C and calcination at 850°C.