Au(III) extraction using ketone compounds with physical properties superior to current commercial extractants

Abstract Dibutyl carbitol (DBC) and methyl isobutyl ketone (MIBK) are commercially available for the extraction of Au(III) from acidic chloride media through ion solvation. These extractants show high Au(III) extractability, but their physical properties have drawbacks in extraction processes. In this study, Au(III) extraction using a series of aliphatic ketone compounds was studied to find a novel extractant with advantageous properties compared with conventional extractants. These ketone compounds showed desirable Au(III) extractability, with those bearing shorter aliphatic chains showing higher extractability. Furthermore, their Au(III) extraction capacities exceeded industrial requirements. These compounds also had improved properties for metal processing compared with commercial extractants, namely, lower solubility in water, lower viscosity, and high flash points. A representative extractant, 2‐nonanone, selectively extracted Au(III) over various metal ions. Gold extracted with 2‐nonanone was recovered quantitatively as metallic gold by reduction using oxalic acid.