Recovery of platinum from iron-containing chloride solutions through electrochemically assisted aqueous reduction

Precious metals are increasing in demand and consumption year by year, especially in the context of the renewable energy revolution. Depletion and scarcity of the world's natural resources calls for an attention shift to the recovery of secondary raw materials. Nevertheless, secondary resources, such as hydrometallurgical process solutions, also contain impurities. Herein, electrochemically assisted aqueous reduction (EAR) is studied to selectively extract platinum by utilizing multivalent dissolved iron species, which are typical impurities in hydrometallurgical solution. As a result, platinum with high purity was successfully recovered from the iron-containing chloride solutions, even when platinum was present at low concentrations. The reaction process of EAR was elucidated by the electro-gravimetric study. The deposition rate and morphology of platinum on the electrode can be flexibly controlled through operational parameters. The effect of the solution composition on EAR process was also investigated, providing potential industrial feasibility of EAR as a refining unit for valuable metals.