Recovery of TiO2-enriched material from vanadium titano-magnetite concentrates by partial carbon reduction and mild acid leaching

Vanadium-titano magnetite (VTM) is a typical resource in China. The typical method used to recover valuable elements from VTM concentrates is by the blast furnace smelting method. However, titanium is nearly all wasted in the form of blast furnace slag. A new pathway towards obtaining TiO2-enriched material for titanium extraction was designed in this study. The main means is the combination of partial carbon reduction and mild acid leaching. After reduction and leaching, most of the iron and other elements are transferred into solution, leaving a TiO2-enriched residue. Iron and vanadium are reclaimed from the leaching liquid later. In this study, the reduction and leaching parameters were optimized, which included reducing at 1000 °C for 3 h with a carbon addition of 6% by mass of VTM and leaching at 80 °C for 3–4 h by using a 0.2 mol/L H2SO4 solution with a liquid-to-solid ratio of 100:1. The dehydrated residue was mainly rutile containing 72.2 wt% TiO2, which is a satisfactory material for Ti extraction. In addition, upon determining the phase composition and the mass loss after reduction with different dosages of carbon, the reduction route for iron in the magnetite phase and the main gas byproduct during reduction were analyzed. This study provides a new idea for extracting titanium from VTM concentrates.