Review on Tungsten Recovery and Sustainable Practices

Abstract

Tungsten, a versatile transition metal located in Group VI of the Periodic Table, is prized for its strength and eco-friendly attributes, finding essential roles in numerous industries. Its applications range from light bulb filaments and X-ray tubes to military technology, thanks to its outstanding hardness and density. In the chemical sector, tungsten compounds act as catalysts, sourced from minerals like wolframite and scheelite via flotation methods. Tungsten's unique capability to form diverse complexes in different oxidation states is notable, with primary minerals being wolframite and scheelite and secondary ones influenced by geological processes. Recovery of tungsten has advanced from historical empirical methods to more efficient and eco-conscious practices involving digestion with soda or caustic soda, crystallisation, and the use of solvent extraction or ion exchange to eliminate impurities. Commercial APT production employs an evaporation crystallization process and pyrometallurgical methods, such as roasting, carbothermic reduction, and electric arc melting, to reduce tungsten oxide to its metal form. These processes, combined with novel approaches and recycling methods, contribute to the versatile and sustainable use of this valuable metal. The provided information summarises the recovery of tungsten from complex sources, including the removal of arsenic from tungsten residues. Key points encompass tungsten recovery methods, hydrometallurgy for tungsten recovery, arsenic removal from tungsten residues, and innovative processes and recycling.