Emerging application of biosurfactants in metal extraction

Due to their environmental benefits and rich interfacial and colloidal properties, biosurfactants show promise as a platform for next-generation reagents in metal extraction using froth and foam flotation. While the development of biosurfactants as flotation bioreagents is still in its infancy, it has witnessed important progress in the past five years. Recent studies have not only demonstrated the ability of biosurfactants to compete with conventional collectors but have also provided valuable insights into the experimental parameters affecting these two separation processes. Despite this progress, the interactions of biosurfactants with mineral particles, metal ions, and air bubbles under flotation conditions remain far from being fully understood. There is growing evidence suggesting that these interactions are more complex than observed for conventional petroleum-based collectors. We summarize the recent progress and outline the main remaining knowledge gaps, aiming to generate more interest in the intriguingly complex multifunctional properties of biosurfactants as collectors.