Outotec - Circofer Coal-Based Reduction Plants

Circofer pre-reduction essentially consists of a circulating fluidized bed (CFB) where the iron ore is reduced by carbon monoxide and hydrogen gas generated from in-situ coal gasification. The offgas from the CFB is used to pre-heat the iron ore in a 2-stage suspension preheater. The iron ore is then further heated up by recycled char and through partial combustion of coal with oxygen in the heat generator. After the preheating stages the offgas is further cooled in a waste heat boiler (generating steam for the CO2 scrubber) and finally cooled down in a venturi scrubber to remove the water vapor generated during the reduction. CO2 as remaining product from the reduction is removed in a CO2 scrubber and the carbon monoxide and hydrogen process gas is returned to the reduction stage.

Circofer pre-reduction can be combined with Outotec’s coal based Auslron smelting reduction or electric smelting to produce pig iron or hot metal. These combinations increase the capacity of the downstream smelting furnace and, in the case of electric smelting, decrease the power consumption of the smelter. In addition two costly and environmentally harmful steps in traditional iron making, namely coke production and iron ore sintering, would be eliminated.