Freeport-McMoRan is engaged in mineral exploration and development, mining and milling of copper, gold, and silver in Indonesia, and the smelting and refining of copper concentrates in Spain and Indonesia. They are the world's lowest-cost copper producer and one of the world's largest producers of copper and gold. FCX's operations are conducted through its subsidiaries, P.T. Freeport Indonesia (PT-FI), P.T. IRJA Eastern Minerals Corporation (Eastern Mining) and through Atlantic Copper, S.A. (Atlantic).