The miner commissioned three companies for scoping and drilling work to help to move its Lemphane kimberlite project in Lesotho to inferred resource status.
The litigation alleges that the 30 named miners, including big names such as AngloGold Ashanti (NYSE:AU), Goldfields (NYSE:GFI) and Harmony Gold (NYSE:HMY), knew of the dangers posed to workers by silica dust for more than a century.