Rapid and selective gold recovery from waste random access memory in a non-aqueous solvent acetic anhydride

In this study, we have successfully demonstrated a rapid and selective leaching system for Au from waste random access memory (WRAM) using acetic anhydride as a non-aqueous solvent with the combination of HCl, H₂O₂, and CaCl_2. Under optimal condition, Au was selective leached out under 5 min with a high solid/liquid ratio. The optimization results also highlighted that HCl was the most influential factor. Further experiments revealed that Cl^- ions move more freely in the acetic anhydride solvent, facilitating Au dissolution. Furthermore, the leaching proved repeatable and retained high efficiency for up to 7 cycles with an overall efficiency of 93.8 ± 1.1 %. Subsequently, Au was recovered with a 99.8 % efficiency using Na₂S₂O₅. The feasibility of the proposed Au recovery process revealed a profit margin of $25,000/ton of recycled WRAM. Hence, this study presents a novel and efficient approach for the rapid and selective leaching of Au in e-waste recycling.