In the Corex process, all metallurgical work is carried out in two separate process reactors – the reduction shaft and the melter gasifier. Since coking and sintering plants are not required for the Corex process, substantial cost savings of up to 20% can be achieved in the production of hot metal, of a grade similar to that of the blast furnace. Regarding environmental concerns, Corex plant emissions contain only insignificant amounts of NOx, SO2, dust, phenols, sulfides and, ammonia. Emission values are already far below the maximum values allowed by future European standards. Furthermore, waste-water emissions from the Corex process are far lower than those in the conventional blast-furnace route.
Direct use of Non-coking coal
As the coal is chared inside the melter gasifier, even non-coking coal can be used, making a coking plant unnecessary. The high dome temperature exceeds 1,000°C, resulting in entire cracking of the coal‘s relieved hydrocarbons and avoiding the formation of tar.
High fraction of Lump ore
The typical iron oxide mix for Corex is 30% lump ore and 70% pellets. Operational results proved stable operations with a lump ore fraction up to 80%. In addition, no sinter – and therefore no sinter plant – is necessary for optimal operation.
Use of Pure oxygen
While blast furnace operators aim to enrich the hot blast with oxygen, Corex already uses high-purity oxygen, resulting in nearly nitrogen-free top gas. Due to its high calorific value, this gas can be recycled for reduction work or used for heat or energy generation. Depending on the steelworks demand, additional value can be created with the produced gas.
Fig.1- MERIM plant layout
Fig.2- Briquetting of by-products
Jindal South West Steel Ltd. (JSW), Toranagallu, India
Economical iron making basis for a new steelworks in an isolated area with limited access to fuel gas.
Corex-DR combination consisting of two Corex C-2000 plants with a total annual output of 1.6 million tons of hot metal and a MIDREXTM DR plant with an annual output of 1.2 million tons of DRI.