Hydrometallurgical Approach to Recover Vanadium and Aluminum from the Sulfuric Acid Manufacturing Spent Catalyst

This is the authors' abstract. We don't add key points for this paper.

The current study investigated a comprehensive hydrometallurgical process designed for the selective recovery of vanadium (V) and aluminum (Al) from spent catalysts used in sulfuric acid manufacturing (SAM), to promote sustainable recycling of industrial waste. The process began with alkaline leaching using 0.5 M NaOH which effectively dissolved both metals under optimized conditions (25°C, 10 min, and a solid-to-liquid ratio of 100 g/L), resulting in a silica-rich residue. The resulting leach liquor, containing vanadium (V(V)) and aluminum (Al(III)), was subjected to solvent extraction with 10% Aliquat 336. Vanadium was selectively extracted at a pH of approximately 2, using an organic-to-aqueous (O/A) ratio of 1:1. Then, vanadium was stripped from the loaded organic phase using NaOH, producing a vanadium-enriched aqueous solution. Vanadium precipitated as ammonium metavanadate (NH4VO3) at 60°C and a pH around 7, using ammonium chloride. Concurrently, aluminum was recovered from the raffinate by precipitation as aluminum hydroxide (Al(OH)3) at a pH of approximately 7.1, using sodium hydroxide and sulfuric acid as pH adjuster. The developed process demonstrated high metal recovery rates with minimal environmental impact. This study underscores the effectiveness of integrating leaching, solvent extraction, and precipitation techniques for sustainable resource recycling from industrial waste.