EARTH

[3901-12-04] Improvement of copper leaching in sulfuric acid by adding oxygen and cupric ion

○Kyoungkeun YOO¹ (1. Korea Maritime and Ocean University)

司会（Chairman）：Kyoungkeun Yoo （Korea Maritime and Ocean University）, Naoki Hiroyoshi (Hokkaido University)

キーワード：copper leaching, aeration, sulfuric acid medium, cupric ion

Copper metal is more noble than hydrogen so, generally, another oxidant such as Fe³⁺ ion, H₂O₂ was required to oxidize copper or HNO₃ or HCl leach medium were used for copper leaching. There are some drawbacks in the conventional studies and processes; further separation process (Fe³⁺); Difficulty managing due to instability of reagent (H₂O₂); hazardous gas emission (HNO₃); high corrosiveness (HCl). In the present study, the leaching behavior of Cu was investigated under the following four leaching set; without aeration and cupric ion, with aeration but no cupric ion, with cupric ion but no aeration, with cupric ion and aeration. The leaching results showed the highest leaching efficiency by adding both air and cupric ion. The leaching efficiency increased with increasing temperature, agitation speed, initial cupric ion concentration but with decreasing particle size and pulp density. Because Cu is oxidized and leached into Cu²⁺, the cupric ions could be reused in the leaching step. These results indicate that copper leaching was achieved successfully in sulfuric acid solution with cupric ion and oxygen introduction.