Construction of MoS2@Activated Alumina Beads as Catalysts for Rapid Gold Recovery from Au(S2O3)23– Solution

Gold recovery from thiosulfate leaching solution Au(S2O3)23– is regarded as a tough task because of the low efficiency and complex procedure in current technology, which hindered the industrial application of this eco-friendly technique. In this work, a MoS2@activated alumina bead composite (MoS2@AA) was constructed through a simple hydrothermal anchoring method and served as a catalyst to recover gold from Au(S2O3)23– solution for the first time. The microstructure and chemical component of MoS2@AA were systematically analyzed. In addition, batch experiments were carried out to explore the recovery behavior of Au(S2O3)23– (concentration: 10 to 200 ppm). Ascribing to the extraordinary optical property of MoS2@AA, Au(S2O3)23– could be directly reduced to Au0 by photogenerated electrons and then form a two-phase interface of gold/MoS2@AA. As a result, the recovery of Au(S2O3)23– can reach up to 98% on MoS2@AA, which was much higher than traditional methods. More importantly, the reduced Au0 could be desorbed from MoS2@AA through a supersonic method, achieving one-step Au0 recovery from Au(S2O3)23–. This novel strategy used in this research has great significance to the development of Au(S2O3)23– recovery in the future.