Phase composition of the vanadium-containing titanium slags forming upon the reduction smelting of the titanomagnetite concentrate from the Kuranakhsk deposit

The phase composition of the vanadium-containing titanium slags that form upon the reduction smelting of the titanomagnetite concentrate from the Kuranakhsk deposit with an added CaCO3 flux is studied by optical microscopy, X-ray diffraction, and scanning electron microscopy. The laws of formation of the phase composition and the interphase distribution of vanadium and other elements are revealed as a function the CaO and FeO contents in the slags. It is shown that, at low CaO contents (up to 5%), the phase composition of the slags containing 15–30% FeO is mainly represented by spinelides (Al-V-Cr and Al-Ti-V spinels and (Fe,Mg)2TiO4 ulvospinel), anosovite, and glass. When the CaO content in slag increases, titanium is fixed into perovskite. At 17–20% CaO and ≤8.3% FeO in slag, a new crystalline phase, i.e., Ca-Al-V titanate of a complex composition, forms along with perovskite, the Al-V-Cr spinel, anosovite, and glass. Vanadium in the slags is mainly distributed between anosovite, the spinelides, and the Ca-Al-V titanate, and vanadium is absent in the glassy phase.