Outotec Process Solutions and Equipment for Hydrometallurgical Treatment of Cu Sulfides

摘要

This paper outlines hydrometallurgical copper sulfide leaching options as alternatives to the more conventional pyrometallurgical processing route for copper sulfides. Three copper sulfide leaching and refining processes are discussed, total pressure oxidation, ferric sulfate leaching and copper chloride leaching. Ferric sulfate leaching and copper chloride leaching are carried out at atmospheric pressure while total pressure oxidation takes place at elevated pressures. In general the selection of a hydrometallurgical process for use in a commercial application will require that many of the following characteristics are satisfied by the process selected: The use of proven unit processes and equipment. High metal recovery and good product quality. The recovery of other valuable metals such as gold and silver can be carried out economically. The process is flexible in terms of the mineralogy, grade and impurity concentrations it can handle, while still delivering a safe and robust operation with minimal environmental impact. - The technology should be suitable for retrofits e.g. the conversion of a copper heap leach, solvent extraction (SX) and electrowinning (EW) facility once the oxide and transition material is exhausted (Valkama 2013). Throughout this paper, 'copper sulfides' describe both mixed copper iron sulfides, such as bornite and chalcopyrite (Cu5FeS4 and CuFeS2, respectively) as well as copper sulfides, such as chalcocite, digenite and covellite (Cu2S, Cu9S5 and CuS, respectively).