Oxidation behavior of low-grade vanadiferous titanomagnetite concentrate with high titanium

In order to clarify the oxidation mechanisms and make better use of the low-grade vanadiferous titanomagnetite concentrate with high titanium (LVTC), the oxidation behavior of LVTC was investigated. The results showed that oxidation degree was achieved within 90 min when temperature was not lower than 700 °C, and the main phases of the oxidized LVTC consisted of Fe 9 TiO 15 , Fe 2 O 3 , CaSiTiO 5 and a small amount of Fe 2.75 Ti 0.25 O 4 . Increasing temperature is favorable to the formation of Fe 2 TiO 5 . The surface of LVTC gradually becomes rough, with fine particles of needle-like and granular shape appearing on the surface, which finally turn from laminar to creamy, spread out, and are interspersed with many tiny holes. The phase oxidation paths in LVTC were as follows: (1) Fe 2.75 Ti 0.25 O 4 → Fe 9 TiO 15 + Fe 2 O 3 ; (2) Fe 2.75 Ti 0.25 O 4 → Fe 2 O 3 + FeTiO 3 → Fe 2 TiO 5 ; (3) FeTiO 3 → Fe 2 O 3 + Fe 2 Ti 3 O 9 → Fe 2 TiO 5 . LVTC is predominantly mesoporous whether oxidized or not, with the pores mainly distributed in the range of 2–40 nm, and the specific surface area of LVTC decreases significantly with increasing temperature.