Electrochemical decomposition of vanadium slag in concentrated NaOH solution

•An electrochemically enhanced vanadium slag decomposition process was proposed.•Electrochemical oxidation principles were discussed.•The optimized decomposition conditions were determined.•Comparison of typical liquid-phase oxidation methods were carried out.

A novel method that introduces an electrochemical field to enhance the decomposition of vanadium slag in concentrated NaOH solution was proposed. Under the optimal conditions (alkali concentration of 40 wt.%, reaction temperature of 120 °C, alkali-to-ore mass ratio of 4:1, stirring speed of 1000 rpm, and slot current density of 750 A/m2), the extraction percentages of vanadium and chromium could reach approximately 95% and 90%, respectively, after 6 h of reaction time. Compared with the current liquid oxidation methods, the reaction temperature in this new approach is reduced by 60–280 °C and the medium concentration is decreased by more than 30%, demonstrating substantial advantages and prospects in terms of actual operation and industrial application.