A low-ammonium consumption method for preparing high-purity VO from vanadium-rich liquids with high impurity content.

The conventional method for preparing VO from vanadium-rich leachate suffers from three significant drawbacks: low purity, excessive ammonium consumption, and the generation of high-ammonia-nitrogen wastewater. To address these challenges, this study introduces an integrated process involving D2EHPA saponification extraction, hydrolysis vanadium precipitation, and ammonium purification for the production of high-purity VO from high-impurity vanadium-rich liquid. After three-stage counter-current extraction at a 60% saponification degree, 40 vol% D2EHPA concentration, an initial pH of 1.8, a phase ratio (O/A) of 2 : 1, and an extraction time of 8 minutes, followed by three-stage counter-current stripping at 2 mol L HSO concentration, a phase ratio (O/A) of 2 : 1, and stripping time of 20 minutes, the concentrations of Fe and Al in the stripping solution were 0.034 g L and 0.439 g L, respectively. These contaminants were effectively eliminated with removal efficiencies of 98.78% and 97.93%. At an ammonium addition coefficient of 1, VO was prepared with 99.9% purity using the hydrolysis vanadium precipitation-ammonium salt purification approach, which consumed 83% less ammonium salt compared to the ammonium precipitation method. This study significantly reduces ammonium salt usage and provides a scalable, environmentally friendly process for high-purity VO production.