Bismuth Extraction and Refining in the Critical-Minerals Era: A Critical Review from Primary Ores to Circular Secondary Resources

Bismuth is a low-toxicity minor metal whose supply chain depends overwhelmingly on by-product recovery from lead, copper, tin, and tungsten refining, increasingly supplemented by secondary sources including anode slimes, electronic waste, and end-of-life Bi2Te3 thermoelectric modules. Recent Chinese export restrictions, together with a geographically concentrated supply base exceeding 80% of world output, have elevated bismuth to critical-mineral status across multiple jurisdictions. This review critically evaluates bismuth extraction and refining technologies reported over the period 2020-2026, assessing industrial viability, scale-up constraints, and techno-economic trade-offs rather than merely cataloguing process variants. Sulfur-fixing alkaline pyrometallurgy successfully eliminates SO2 emissions but incurs high flux consumption; methanesulfonic acid (MSA) systems and deep eutectic solvents (DES) offer environmental advantages that are only realised if reagent regeneration losses are kept below 1-2 wt%; and cyclone slurry electrolysis achieves single-reactor Bi recoveries above 91% but remains at Technology Readiness Level (TRL) 3-4 due to mechanical wear and capital intensity. The 5N-6N high-purity refining cascade is mapped and a unified decision framework for process selection is proposed. Tangible opportunities for emerging economies, particularly India, to establish resilient domestic bismuth recovery hubs from existing smelter intermediates and e-waste streams are highlighted.