Gold Concentrate Roasting

Gold concentrate roasting, most commonly known as dead roasting, uses Metso Outotec's circulating fluidized bed technology. When using a dead roasting process for concentrates, the sulfides are completely transformed into oxides. The gas temperature in this type of plant is typically between 600 and 700°C. The hot gas generated in the process is used for heat recovery and is suitable for high-pressure steam production in a waste heat boiler. Even low-sulfur and organic contents are removed efficiently, leading to increased gold recovery in the downstream leaching process.

• Direct dry or slurry feeding of the concentrate to the roaster       
• High combustion velocity results in low residual sulfur in the calcine    
• Maximized heat recovery in the fluidized bed in conjunction with an off-gas waste-heat boiler    
• Chlorine and fluorine removed from concentrate during roasting