Boss Mining has a long history of copper and cobalt production from significant open-pit resources and has the capacity to produce cobalt oxide and sulphide concentrate, cobalt carbonate, cobalt hydroxide and copper cathode. It is located in the south-eastern Lualaba and Katanga provinces. Its assets in Kakanda and Luita include open cast mines, crushing beneficiation- and concentrator plants, as well as an electroextraction facility. In February 2019 Boss Mining was placed on care and maintenance.

In November 2022, ERG and its joint-venture partner, La Générale des Carrières et des
Mines (Gécamines), restarted production at Boss Mining on a limited scale, through the processing of historical mined fines to produce copper cathodes and cobalt hydroxide. Boss Mining operations will be sustainably developed and scaled to allow for positive, long-term social, environmental and economic outcomes.