Most of the copper produced worldwide comes from sulfide minerals, and a majority of production is through smelting as opposed to the use of hydrometallurgical methods. As easily-accessed sulfide mineral deposits are depleted, producers must mine the more complex sulfides, which are more difficult to process. The concentrates from these sulfides contain various impurities, like arsenic, in copper minerals such as enargite and tennantite. These minerals are present in many copper orebodies. Copper producers worldwide are required to meet increasingly stringent environmental regulations for gaseous, aqueous and solid waste emissions to the atmosphere. As a result of these regulations, difficulties may be encountered with conventional smelting technology when treating minerals with elements such as arsenic. Conventional smelting/ converting technology has a limited capacity and capability to treat arsenic-contaminated concentrates because of the risk of atmospheric pollution and copper cathode quality. When treated pyrometallurgically, arsenic minerals tend to react easily forming volatile oxides or sulfides or an impure copper product. Many globally significant copper properties have copper sulfide mineralogy high in arsenic present as enargite, Cu3AsS4. The enargite may contain significant amounts of contained precious metals. Development of a selective hydrometallurgical approach to efficiently treat copper concentrates containing large amounts of arsenic would eliminate the issue of atmospheric pollution and may be relatively easily integrated into existing pyrometallurgical operations. In order to evaluate an economic hydrometallurgical process to treat enargite, a background understanding of copper processing, arsenic behavior and enargite mineralogy is essential.