A sample of Cu/Co flotation concentrate from Oz Minerals’ Carrapateena mine in Western Australia was subjected to sulfation roasting under conditions predicted to favor conversion of copper and cobalt sulfides to sulfates. Most of the past attempts by plant operators and many researchers to apply sulfation roasting to primary sulfide minerals, including bornite and chalcopyrite, have generally failed. The obstacle to success has been formation of the acid-insoluble copper ferrite. The only sulfation roasting and roaster calcine leaching project that has ever achieved commercial scale for chalcopyrite concentrates was the Lakeshore operation in southern Arizona in the 1970s. Since Lakeshore was eventually a financial failure, this paper summarizes the operation’s technical features and history and demonstrates that sulfation itself was successful. Following a literature search, two thermodynamic studies were conducted, and an operating window for sulfation by fluidized bed roasting was found to be 650–680 °C with an air-to-solid mass ratio of 18:1. Leaching of the calcine with dilute sulfuric acid extracted 97% of the copper and 83% of the cobalt. The residue was washed, neutralized, and leached with aqueous sodium cyanide, resulting in extractions of gold and silver, respectively, of 99 and 78%.