Efficient preparation of AlV65 alloy through aluminothermic reduction of sodium metavanadate precipitated from shale V-rich solution

The use of Al–V alloys as intermediate additives is pivotal for producing high-performance Ti alloys. Traditionally, the synthesis of these alloys relies on high-purity V₂O₅, with sodium metavanadate as an essential intermediate in V₂O₅ production. This study explores an alternative approach utilizing sodium metavanadate directly, offering an aluminothermic process to alleviate the environmental impact and reduce the time required for V₂O₅ preparation. Al–V alloys are synthesized using sodium metavanadate derived from a shale V-rich solution, and the impurity-migration behaviors are comprehensively analyzed, specifically focusing on Fe, Al, and Na. The results reveal that Al interacts with CaO to form a slag phase that is different from the alloy, whereas Na undergoes a sequence of reductions (NaVO₃ → Na₂V₂O₅ → NaVO₂ → Na) and volatilizes at 25–1200°C, thereby avoiding incorporation into the alloy. Fe, reduced by Al, enriches the alloy phase and induces a phase transition (Al–V → Al–Fe → Fe–V) in the presence of excess Fe. Sodium metavanadate (Fe ≤ 0.05wt%) derived from the shale V-rich solution enables the production of a uniform AlV65 alloy with 66.56wt% V, 33.14wt% Al, 0.08wt% Fe, 0.07wt% C, 0.02wt% N, and 0.12wt% O. These results establish a streamlined, efficient framework for the future preparation of Al–V alloys from shale V-rich solutions.