Smelting Reduction

Smelting reduction processes are the latest development in pig iron production. These processes combine the gasification of coal with the melt reduction of iron ore. Energy intensity of smelting reduction is lower than that of blast furnace, as the for coke production is not needed and the need for ore preparation is reduced.

Smelting ReductionSchematic

Smelting ReductionTechnologies & Measures

Technology or MeasureEnergy Savings PotentialCO2 Emission Reduction Potential Based on LiteratureCostsDevelopment Status
Corex Process

Dry fuel consumption with and without off-gas recycling is reported to be 770 kg/t-HM and 940 kg/t-HM.
With a combined cycle power plant and off-gas recycling combined, the net thermal and electrical energy consumption for a 1 million t/y capacity plant is reported to be 450 and 45 MW, respectively(Siemens VAI).

CO2 emissions per ton of combined product (hot metal + DRI) are lower by ~20% compared to blast furnace route (APP, 2010. p.56)

Total CO2 emissions for steel produced with 60% hot metal from Corex and 40% DRI is reported to be around 3.78 t/t-steel (US DOE, 2003)

Reported capital costs were in the range of €195 per ton of annual production (IPPC, 2012. p. 528).

Capital and operational costs for producing steel with 60% Corex hot metal and 40% DRI is reported to be $373.5 and $218.3 per ton of steel, respectively (US DOE, 2003. p.4/4)

Finex Process

Coal consumption of the process is less than 700 kg-coal/t-HM.

An additional energy reduction of 1.3 GJ/t-HM is reported by utilizing off-gases after CO2 removal.


The process is reported to have 4% less CO2 reductions, as compared to blast furnace route. 

According to the company, the capital and operational costs of Finex are 15 – 20% lower than conventional BF route (Siemens VAI).


With no raw material processing required, the HIsmelt process uses less energy to produce each tonne of hot metal.

This technology can reduce CO2 emissions per tonne of hot metal by close to 20% when compared to the typical BF route.

Production costs are in the range of 95% to 65% of the conventional route costs.

Dios Process

Net energy consumption decreases by 3 to 4%. Low direct electrical power consumption. Coal Consumption in Dios process is 950 kg/tHM.

CO2 emissions in the Ironmaking process decreased by 4 to 5%.

Investment costs for the technology are 65% of that of BF investment cost.


Hisarna technology opens the opportunity of 20% improvement in steel industry energy efficiency.

20 % reduction of CO2/t-hot rolled coil (HRC) without carbon capture and storage (CCS) is expected. Morevoer, reduction of upto 80% in CO2/t HRC is possible with CCS.

Investment and/or operational costs are not available because the technology is still in research.

Cyclone Converter Furnace

Coal consumption of this furnace is 700-750 kg/tHM. Energy consumption per tonne steel will be lower. Furthermore, power can be generated from the flue-gases which exit the cyclone at about 1800°C.

Since no coke oven plant, sinter or pellet plant are required, a remarkable reduction of emissions can be achieved.


Its Coal consumption is reported to be 900-1200 Kg/tonne. Energy consumption per tonne steel will be lower.

Since no coke oven plant, sinter or pellet plant is required, a significant emissions reduction compared to conventional primary ironmaking can be expected.


This technology ensures high productivity and energy efficiency in the furnace. Full metalization upto 99% can be achieved.

Capital requirement for steel production with 30% Tecnored hot metal and 70% scrap to the EAF, with and without Co-generation are reported to be $196.5 and $187.7 per ton of liquid steel.
The operational costs of the technology with and without co-generation is reported to be $192.41 and $205.72 per ton of hot steel, respectively (assuming scrap price of $120/t-scrap)(US DOE, 2003).