COREX® Process

COREX®, a unique smelting-reduction process, enables the cost-effective and environmentally friendly production of hot metal from iron ore and coal. In the COREX® process, a coal-based smelting reduction process, all metallurgical work is carried out in two separate process reactors—the reduction shaft and the melter gasifier. By eliminating the need for coke ovens and sinter plants and utilizing lower-cost coal compared to the blast furnace route, the COREX® direct reduction process achieves significant cost savings of up to 15% in hot metal production. COREX® plant emissions contain only insignificant amounts of NO_X, SO₂, dust, phenols, sulfides, and ammonia, so emission values fall below the maximum values permitted by European standards. Furthermore, wastewater emissions in this direct reduction route are far lower than in the conventional blast furnace route.

Advantages of the COREX® Process

Direct Use of Non-Coking Coal

The COREX® process enables coal to be charged directly into the melter gasifier, allowing the use of non-coking coal and eliminating the need for a coking oven. The high dome temperature exceeds 1,000°C, resulting in cracking of the coal’s relieved hydrocarbons, avoiding the formation of tar. The cost of coal for the COREX® process is approximately 40% lower than that of coking coal used for the blast furnace route.

A High Proportion of Lump Ore

The typical iron oxide mix for COREX® is 100% pellets; however, a lump ore fraction of up to 80% has also been demonstrated. The iron ore mix depends on the price of lump ore available. In addition, the COREX® process does not require sinter, so a sinter plant is unnecessary.

Use of Pure Oxygen

Blast furnace operators strive to enrich the hot blast with oxygen, but nitrogen is a burden. The COREX® process uses high-purity oxygen, producing a nearly nitrogen-free top gas. With a high calorific value, this gas can be used for reduction work, heat, or energy generation, or to produce ethanol and acetic acid using gas fermentation processes, such as the proprietary fermentation process from LanzaTech. Since each steel production plant is unique, the additional value generated from top gas can be suited to each customer's particular needs.