A CO ₂ -Strengthened, Self-Sustaining Electrolyte Strategy for Antimony Production

The conventional pyrometallurgical production of antimony is energy-intensive and heavily reliant on carbon, resulting in significant CO2 emissions and environmental toxicity concerns. Herein, we engineer a transformative electrolytic process that simultaneously addresses energy efficiency and environmental impact. This process leverages the unique properties of antimony oxide (Sb2O3), which serves as a self-sustaining, fluoride- and chloride-free electrolyte at 800 °C. Furthermore, we introduce carbon dioxide (CO2) not as a waste gas, but as a process-intensifying mediator. Under a 1 atm CO2 atmosphere, the dissolved gas drastically enhances anode bubble dynamics and initiates a strengthening cycle, enabling a dual-path (electrochemical and chemical) reduction mechanism. This engineered system achieves a landmark 937% increase in production rate and reduces the specific energy consumption to 52.35 kW·h/t-Sb. Most significantly, compared with the energy consumption of traditional smelting, the total carbon consumption of this process is only 57.95 kgce/t-Sb, representing a reduction of approximately 84.5% compared to conventional pyrometallurgy (304.44 kgce/t-Sb). Synergy with eutectic carbonate salts (e.g., K2CO3–Li2CO3) further intensified the process. Our work exemplifies how chemical engineering principles can be harnessed to create a quantifiably more sustainable and industrially viable metal production pathway, turning a greenhouse gas into a key process ingredient for green metallurgy.