Leaching of Copper from Cementation Precipitate in Sulfuric Acid Solution with Cupric Ion and Oxygen

Abstract

In zinc hydrometallurgical processes, copper was removed as copper precipitate powder by a cementation process, and, in the present study, leaching medium using Cu²⁺ and O₂ in sulfuric acid solution was proposed to enhance the leaching rate of Cu from the cementation Cu precipitate powder. The leaching efficiency of Cu increased with increasing agitation speed, temperature, and initial Cu²⁺ concentration and decreasing pulp density. When the effect of gas type on the leaching was examined, the leaching efficiency was faster in the order of O₂, air, and N₂. The leaching efficiency of Cu increased to 100% in 1 mol/L sulfuric acid solution at 70°C and 600 rpm with 2% pulp density, 10000 mg/L Cu²⁺ and 1000 mL/min O₂. In the kinetic study, the leaching behavior of Cu followed the reaction-controlled model, and the activation energy was determined to be 19.2 kJ/mol. Therefore, these results suggest that the addition of Cu²⁺ and O₂ could enhance the leaching rate of Cu from the cementation Cu precipitate.