The iMpunzi Mining Complex is a large export bituminous coal mining operation located 110 km east of Johannesburg and 27 km south of the town of Witbank, in the Mpumalanga province of South Africa. iMpunzi is the Zulu word for the Duiker antelope. The complex consists of two underground mines, Phoenix Colliery and Arthur Taylor Colliery, and an opencast mine ATCOM (Arthur Taylor Colliery Opencast Mine). Since 1 January 2007 the iMpunzi Mining Complex has been 100% owned by Xstrata Coal.

The Phoenix Colliery produces a 6000k/c high grade washed steam coal for the export market and a 5100k/c product for use in local power stations. Arthur Taylor Colliery and ATCOM produce a 6000k/c high grade washed steam coal for the export market.

Phoenix Colliery Ltd. commenced operations in 1936 and in 1958 Consolidated Collieries became a wholly owned subsidiary of Phoenix Colliery. In 1973 Phoenix Colliery became part of Tavistock Collieries Ltd. In 1981, the mines became part of a joint venture between Tavistock Collieries Ltd and Total Exploration South Africa Limited.

ATCOM was constructed in 1990 within the boundaries of Phoenix Colliery and in 1998 Duiker Mining acquired Tavistock Collieries and renamed the operations the iMpunzi Division. Xstrata PLC purchased Duiker Mining from Glencore in 2002 and at the end of 2006 the TESA joint venture came to an end.

Xstrata announced the restructure of its Douglas Tavistock Joint Venture (DTJV) with BHP Billiton Energy Coal south Africa (BECSA) in March 2008. Under the terms of the restructuring, Xstrata acquired and now manages the mining of reserves approximately equivalent to its original 16% share in the DTJV, in an area contiguous to its ATCOM operations. Separate mining operations commenced on 1 July 2009. The restructuring enabled Xstrata to integrate the acquired discrete reserves from the former DTJV into its ATCOM complex, to leverage existing infrastructure and take direct management control of the operation, which was renamed ATCOM East.