Good news for Smelting professionals: Technology for decarbonizing steel production is here!

The hydrogen-based direct reduction process combined with an electric arc furnace (EAF) is a known solution for the industry, but this combination is not going to solve the decarbonization challenge. The reason for this is the demand of high-quality iron ore. EAF cannot tolerate the high slag volumes that are generated in the processing of DRI from blast furnace grade iron ore. It has been estimated that currently only 4% of global iron ore supply meets the requirements of the H₂-DRI +EAF steel making route. Therefore, demand and price of high-quality iron ore will increase dramatically in the future.

As about 71% of the existing blast furnace capacity will reach the end of its operational (relining) life before 2030, new reliable steel making processes are needed already today, if not tomorrow. Therefore, we have launched the new DRI Smelting Furnace. 

The Metso Outotec DRI Smelting Furnace can handle large slag volumes without excess iron losses, thereby allowing the use of blast furnace grade iron ore. It is a continuously operating process securing high production volumes in the steel plant. By combining direct reduction plant with our DRI Smelting Furnace and feeding DRI hot from a direct reduction plant directly into a smelting furnace, the energy efficiency of the process route can be further improved.

High capacity with the ‘six electrodes in line’ concept

Metso Outotec’s rectangular DRI Smelting Furnace can meet high capacity and availability demands of blast furnaces. The “six electrodes in line” furnace can produce more than 1.2 Mt/y of hot metal. Several DRI Smelting Furnaces can be combined using joint facilities and utility areas. Traditional circular open slag bath furnaces from our portfolio are suitable for capacities up to 1.0 Mtpa.

The main products of the DRI Smelting Furnace process are hot iron metal with required carbon content, excellent quality slag and furnace off-gas with high chemical energy content. Hot metal carbon content is adjustable to meet the requirements of the next process step but also depended on carbon content of the DRI used as a raw material.

DRI Smelting Furnace technology in iron and steel production chain

Metso Outotec DRI Smelting Furnace can be erected in the vicinity of existing blast furnace and direct reduction plant and ramped up while blast furnace is operating. After successful ramp-up, blast furnace can be demolished. This kind of project arrangement allows stable production to the steel plant without unnecessary production stoppages. The DRI Smelting Furnace product can also be tuned to meet requirements of the downstream process by carbon and silica level in hot metal, and also by volume and interval of tapped metal tons.

Our DRI Smelting Furnace can also be erected close to an iron ore mine site together with direct reduction plant. In such case, hot metal produced can be cast for instance to ingots or preferably granulated to suit to be used as a raw material in the day bin systems of a steel plant without a separate crushing and screening step. This arrangement is especially tempting when green energy is available for the iron ore mine, allowing the production of high value, gangue, and impurity free premium product. Metso Outotec DRI Smelting Furnace technology allows iron mines to integrate further in the steel value chain by producing high-quality “green iron granules” suitable for common steel making processes.

The next steps

In Metso Outotec’s Pori Research Center, DRI smelting pilot tests will be arranged in early 2023 to demonstrate the functionality of process metallurgy and to determine operational range of the DRI Smelting Furnace. For this purpose, the existing AC-pilot furnace has been redesigned.

Going forward, we are also planning to construct a completely new pilot furnace. The concept would demonstrate a rectangular structure of industrial DRI Smelting Furnace instead of existing circular shape furnaces. This would allow our customers to get familiar with the new concept and gain confidence for our new DRI Smelting Furnace, while also enabling us to demonstrate the important cooling ad refractory binding solutions. The decision of this new pilot furnace is expected soon, and the construction phase is expected to take ~18 months.

During the next months, we’ll be actively discussing the new concept in conferences and customer events. If you are interested in a private presentation, we are happy to arrange that for you as well!

This article is part of our Smelting Newsletter 2022. Visit the issue front page for all articles and greetings from Jyrki Makkonen, Vice President of Smelting business line.