Co-recovery of tungsten and lanthanum from photovoltaic tungsten-based busbars scrap by molten salt electrolysis

As a rare-earth reinforced tungsten alloy, photovoltaic tungsten-based busbars have been extensively employed in silicon production in recent years. The urgent issue at hand is the need to achieve the co-recovery of tungsten and lanthanum from photovoltaic tungsten wire scrap. In this study, the complete recycling of photovoltaic tungsten scrap is achieved for the first time through a brief molten salt electrolysis process, utilizing Na2WO4 as the electrolyte and tungsten wire scrap as the anode. The process involves a graphite crucible as the cathode, ensuring continuous contact with the product to prevent the oxidation of tungsten powder (W) to sodium tungsten bronze (NaxWO3) by Na2WO4 electrolyte. The corundum anode basket promotes the dissolution of La2O3 in the electrolyte to form La2(WO4)3. This compound actively participates in electrochemical reactions to facilitate the simultaneous production of W and La2O3. The regenerated tungsten powder possesses a uniform distribution of La2O3, making it a suitable raw material for the manufacture of photovoltaic tungsten-based busbars. Overall, this approach establishes a sustainable and environmentally friendly tungsten resource recycling ecosystem.