How it began
The Teniente Converter was developed at Fundicion Caletones, the smelter of the El Teniente copper mine run by the state company Codelco. Research and industrial operation began there in 1977, and the first unit started work that year. The engineers began by modifying Peirce-Smith converters: they injected concentrate through the tuyeres, the air nozzles in the side of the vessel, and blew with oxygen-enriched air to cut the loss of concentrate.
Before it existed
Chilean smelters melted concentrate in reverberatory furnaces to make matte, a mix of copper and iron sulfides, and then treated the matte in Peirce-Smith converters. The reverberatory step needed fuel to keep the bath hot. The Teniente Converter removed the need for matte from reverberatory furnaces, because the concentrate itself was smelted inside the converter.
How it works
Dry concentrate is injected through tuyeres directly into the molten bath, with air enriched to about 32 percent oxygen at first and later 34 to 38 percent. The sulfur and iron in the concentrate burn and supply the heat, so smelting is autogenous and no additional fuel is needed. The reactor produces white metal with 72 to 74 percent copper and a slag with 8 to 10 percent copper. The white metal then goes to a Peirce-Smith converter to become blister copper. Later versions inject bone-dry concentrate with 0.2 to 0.3 percent moisture.
How it spread
The work at Caletones led to Teniente Converters being installed in other smelters in Chile and abroad. A 2018 review listed units at Chuquicamata, Potrerillos, Ventanas, Caletones and Hernan Videla Lira. The authors add that the reactor never became widely used around the world, because Codelco's aim was to operate it, not to sell it, and its commercial strategy was weak. The Caletones smelter operates with two Teniente Converters, each 5 by 22 meters. The 2018 review counted seven units in five Chilean smelters, where the converter is a standard smelting technology.
