Outotec® Flash Smelting Process, invented over 60 years ago, is Best Available Technique (BAT) according to European Union's classification. It has been nominated as the 'Metallurgical innovation of the 20th century' and awarded the ASM Historical Landmark status. It adds value by a high unit capacity, excellent emission control and cost reduction. Today Outotec® Flash Smelting has achieved a clear leading position as the world’s number one primary copper smelting technology.
The Flash Smelting process is based on utilization of the feed material’s internal energy for smelting. Finely ground sulfidic copper concentrate is mixed with oxygen-enriched air to form a rapidly reacting suspension in the reaction shaft of the Outotec®Flash Smelting Furnace. Sulfide compounds of the feed ignite, oxidize and release heat, acting as a fuel for the process and no external energy is needed for smelting. In the settler of the furnace, molten droplets separate from the gas stream and settle at the bottom of the furnace as distinct matte and slag layers, based on their specific densities.

The molten high-grade matte produced in the Flash Smelting Furnace is led through covered launders directly to granulation, where the matte is dispersed and granulated by means of high-pressure water jets. The Flash Smelting slag is directed to a slag cleaning furnace or slag concentrator for copper recovery. The matte granules are ground into a grain size suitable for completing the oxidation reactions in the Flash Converting Furnace.