Flash smelting (Finnish: Liekkisulatus) is a smelting process for sulfur-containing ores [1] including chalcopyrite. The process was developed by Outokumpu in Finland and first applied at the Harjavalta plant in 1949 for smelting copper ore.[2][3] It has also been adapted for nickel and lead production.[2]
The process uses the autogenic principle by using the energy contained in the sulfur and iron for melting the ore.[4] In the process dried and powdered ore is discharged from a nozzle into a fluidized bed reactor fed with oxygen. The reduced metal melts, and drops to the bottom of a settling chamber. The flotation produces a large effective surface area of fine-grained concentrate particles.[4] The process makes smelting more energy efficient and environmentally friendly.[4] Sulfur is released mainly in its solid form, thus reducing atmospheric pollution.[1] The process is today used for 50% of the world’s primary copper production.[2] The other 50% is mainly produced from oxide ores, where the process cannot be applied.
Outotec, formerly the technology division on Outokumpu now holds Outokumpu's patents to the technology and licenses it worldwide.