Electric Furnace Titanium Slag Preparation Of Ti-rich Material Pilot Study

On the basis of analyzing the situation of preparing rich titanium product from electro-titanium slag at home and abroad, in this dissertation, a new method of preparing rich titanium product has been studied. Via experimental investigation, rich titanium product with TiO₂>90% can be prepared from the slag by acid leaching which has leached with sodium hydroxide at high pressure. The prepared rich titanium product was suitable feedstock for chloride pigment and sponge titanium.By using methods of chemical analysis , X-ray diffraction, scanning electron microscope and so on, the X-ray diffraction figures, crystal phases and the phase compositions are obtained, phase compositions are analyzed, the phase compositions including TiO₂, Ti₃O₅, (Mg,Fe)Ti₂O₅, Al₄Ti₂SiO₁₂ etc. The effects of reductant ratio , smelting temperature and cooling temperature on phase compositions of titanium slag are analyzed. The main impurities of electro-titanium Slag are studied, these impurities were formed from melting titanium concentrates. In the process of melting titanium concentrates, some impurities were completely switch to titanium slag such as CaO, MgO, Al₂O₃ etc, some impurities, which can not be completely deoxidized, were partially switch to titanium slag such as SiO₂, MnO, V₂O₅ etc. The removal impurities mechanism from electro-titanium slag was put forward, then the main conclusion was verified by the experiments of leaching by hydrochloric acid at normal presure and sulfuric acid at high pressure. Namely, the great mass of Fe, Mg, Mn, V and other impurities have inertness toward the action of mineral acids, glass silicate phase is present in the form of inclusions, attachments and veins inside the pseudobrookite, it's not viable to raise the rade of TiO₂ to more than 90% only by the acid leaching to remove the impurities directly.By high pressure NaOH leaching, high pressure Na₂CO₃ leaching, andnormal pressure NaOH leaching, then these slags were separately leached by normal pressure, it is proved that the slag which was leached by high pressure Na₂CO₃ and normal pressure NaOH can not be prepared rich titanium product with TiO₂>90%. The slag leached by high pressure NaOH was leached with high and normal pressure acid, it is proved that high pressure acid leaching caused the decrease of TiO₂ and rate of recovery, it is reasonable to choose normal acid leaching.Under the condition of temperature 120°C, pressure 0.2MPa, keeping pressure time 2h, sodium hydroxide concentration 60¹00 (g/l), high pressure sodium hydroxide leaching can destroy the sosloid structure and selectively remove SiO₂ and Al₂O₃ in the Electro-titanium slag, Then rich titanium product of TiO₂>90% was prepared from electro-titanium slag of TiO₂80⁸7(%)by using sulfuric acid leaching and washing, on the condition that temperature>80°C, time 2h, acid concentration 25g/l.