Study on the Chlorination Leaching of Gold and Copper from High Gold-Containing Material Based on Variable Stirring SpeedStudy on the Chlorination Leaching of Gold and Copper from High Gold-Containing Material Based on Variable Stirring SpeedLing, Zhou, Li, Wei, Dong, and Wang

High gold-containing material (HGCM) is the product of waste printed circuit boards (WPCBs) by pyrometallurgy and electrolytic refining. This paper proposes a mixing method based on variable stirring speed to enhance the leaching of gold and copper. The leaching behavior of gold and copper in the chlorination system from HGCM under variable stirring speed was studied, and the results showed that a variable stirring speed can enhance liquid flow and save reaction time. Temperature and acid concentration affect the leaching of metals. Under optimum conditions, gold and copper can be completely leached. Moreover, the gold leaching process was found to conform to the surface chemical-controlled shrinking core model, according to the kinetic curve and an activation energy of 49.47 kJ/mol. In addition, combined with XRD analysis of the raw material and leaching residue, the main phases in HGCM are AuCu3, Au, and Au3Cu. This process delivered complete copper and gold leaching from HGCM under laboratory conditions, and provided a more efficient and fast method for chlorination leaching of metals.