Gold Fields Extending Mine Life at Damang

The Damang gold mine is located in southwestern Ghana near the southern end of the Tarkwa Basin. The mine exploits oxide
and fresh hydrothermal mineralization in addition to Witwatersrand-style palaeoplacer gold. (Photo: Gold Fields)
Gold Fields has announced plans to extend the life of its Damang gold mine in Ghana by eight years from 2017 to 2024 through investment of $1.4 billion in capital and operating expenditures. Over the life of the mine, a total of 165 million metric tons (mt) of material will be mined and 32 million mt will be processed at a grade of 1.65 grams (g)/mt, resulting in total gold production of 1.56 million ounces (oz). All-in costs of production are forecast to average $950/oz.

Since Damang started up in 1997, the mine has produced more than 4 million oz of gold, sourced from multiple open pits. Production from the Damang Pit Cutback (DPCB) came to an end in 2013, and since then mining has focused on the margins of the Damang pit, as well as lower-grade satellite deposits. A decline in production since 2013 has been exacerbated by variations in grade in the northern and southern extremities of the DPCB and the satellite pits, where grades have been lower than expected.

A strategic review initiated in 2015 indicated that Gold Fields should return to mining the higher-grade core of the main Damang orebody. This work was supported by a “development agreement” signed between Gold Fields and the government of Ghana in March.

Major cutbacks will be undertaken to the eastern and western walls of the DPCB, followed by a deepening of the pit by a further 76 meters (m). This work will ultimately provide access to the full Damang orebody, including high-grade Tarkwa Phyllite lithology. Planning for the Damang cutback has resulted in a 72% increase in Damang’s proven and probable reserves to 1.68 million oz of gold in 31.5 million mt at a grade 1.65 g/mt, compared to the December 2015 totals.

To provide short-term ore supply while the Damang pre-strip is in progress, mining will continue at satellite pits, and plant feed will be supplemented by lowgrade surface stockpiles.

As featured in Womp 2016 Vol 12 -