Effective extraction of vanadium from bauxite-type vanadium ore using roasting and leaching

Abstract

A new bauxite-type vanadium ore with a grade of 0.96% V2O5 was found in Hanzhong, China, having quartz, illite, and calcite as the main mineral constituents and vanadium that mainly occurs in the aluminosilicate lattice of illite by replacing Al3+ with V3+ in isomorphism form. In this study, a novel process of low-temperature sulfating roasting–water leaching is presented to extract vanadium from the bauxite-type vanadium ore. Addition of sulfuric acid enhanced the conversion of vanadium to NaVO3 in the sulfating roasting process, and addition of ammonium molybdate improved the leaching efficiency in water leaching. The results showed that a leaching efficiency of 90.33% was obtained under optimal test conditions. The calculation results of standard Gibbs free energy (∆rGθ) further verified that the formation of NaVO3 is feasible.