Mining in Antarctica is banned indefinitely by the Protocol on Environmental Protection (the Madrid Protocol). This important agreement came into force in January 1998.
Before then, the economic challenge of mining in Antarctica prevented any commercial operations. There are deposits of minerals in Antarctica, including coal and iron ore. But getting to them would have required battling the hazardous Antarctic conditions. Miners would have had to get through the thick ice sheet to reach the minerals. Antarctica is also a long way from world markets. Mined minerals would have had to be shipped over the treacherous Southern Ocean.