History of forced aeration in copper sulfide leaching

The development of forced aeration as an approach to enhancing copper sulfide leaching is traced from its earliest development to present day operations. Both large-scale field tests and commercial operations are covered. The historical portion is preceded by an introductory discussion of the role of air (oxygen) in sulfide leaching. Sufficient aeration may be achieved via naturally induced convective airflow. However, cases are identified where this is insufficient, leading to retardation of the sulfide leach rate. For these situations, forced aeration may be beneficial. The historical portion of the paper focuses on major field tests that were conducted in Montana, Nevada and Utah and on commercial operations in the United States, Australia, Chile and Peru. Based on the information developed to date, this paper concludes with some general comments on the applicability of forced aeration.