Effect of mineral phases on the leaching efficiency of Ti slag

Titanium slag obtained from electric-furnace smelting using ilmenite from Panzhihua contains predominately two phases: anosovite and augite. The mineral phase compositions in titanium slag can have severe effects on the leaching process and leaching efficiency. However, the precise role of the effect of mineral phases on the leaching efficiency is unclear. Here, we demonstrate that the formation of boundaries between mineral phases in titanium slag acts as resistance to slow down the leaching rate of titanium from titanium slag in sulphuric acid. We found the dissolution rate of augite phase was much slower than anosovite phase, and the surface area available for the titanium leaching from titania-rich anosovite phase was reduced due to the coexistence of augite and anosovite phases in titanium slag particles. Our results demonstrate that the formation of boundary structures of anosovite and augite phases is an important factor affecting the leaching efficiency of titanium slag.