Extraction of vanadium and enrichment of titanium from modified Ti-bearing blast furnace slag

Abstract An alkali leaching-acid leaching method was proposed to extract vanadium and enrich titanium from modified Ti-bearing blast furnace slag (MTBBFS). The optimal alkali leaching conditions were NaOH concentration 2.0 Mol/L, leaching temperature 95 °C, and leaching time 90 min. The leaching ratio of V was 91.30%. After 4 times cyclic alkaline leaching, the vanadium concentration of leaching solution increased to 14.70 g/L and the solution could be used to recover vanadium by the precipitation of ammonium salt. The optimum acid leaching conditions were HCl concentration 2.0 Mol/L, leaching temperature 65 °C, and leaching time 60 min. The TiO2 content of synthetic rutile and the total recovery ratio of Ti were 99.15% and 97.77%, respectively. Due to the TiO2 content of the rutile >99.00%, the rutile was a high-quality feedstock for titanium dioxide with the chloride process. Moreover, the mechanism of vanadium extraction and the mechanism of alkali leaching-acid leaching reaction process were discussed