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 in producing high-performance Ti alloys. Traditionally, the synthesis of these alloys has relied on high-purity V₂O₅, with sodium metavanadate acting as an essential intermediate in V₂O₅ production. This study explores an alternative approach by utilizing sodium metavanadate directly, offering an aluminothermic process to alleviate the environmental impact and reduce the time intensity associated with V₂O₅ preparation. Al-V alloys were synthesized using sodium metavanadate derived from a shale V-rich solution, with a comprehensive analysis of impurity migration behaviors, specifically focusing on iron, aluminum, and sodium elements. The results reveal that Al interacts with CaO to form a slag phase different from the alloy, while Na undergoes a sequence of reductions (NaVO₃ → Na₂V₂O₅ → NaVO₂ → Na) and volatilizes at 25°C~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 enabled 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.