The direct reduction process is used to produce sponge iron, which can be based on reduction gas or coal. The choice of the gas-based reduction process requires a shaft furnace into which the iron ore is introduced in the upper part. Chemical reduction processes take place through the passage of reducing gas in conjunction with high temperatures around 950 °C. The finished sponge iron falls to the bottom, where it can cool and is protected from reoxidation. As the gas-based process can be flexibly adapted to customers' requirements, three different products can be produced: cold DRI, hot DRI and hot briquetted iron. In a coal-based process, on the other hand, a rotary kiln slightly inclined to the horizontal is used for the reduction process. For this purpose, coal and iron ore are placed in the furnace and heated to a temperature of about 1000°C. The coal is then reduced to the desired temperature. As the furnace rotates, the material moves downward due to gravity and a reduction reaction takes place. The result is directly reduced iron ore and a charcoal mixture that must be cooled in an external water-cooling system for further processing. To separate these two end products, a magnetic separator can be used due to the magnetic properties of direct reduced iron. Direct reducing iron has many advantages such as uniform composition, uniform size and high bulk density. This can result in higher productivity in blast furnaces or better dilution of metallic residues in scrap during steelmaking.
Perantech has been in the steel industry for many years and also specializes in the production of steel from various raw materials and equipment. Steel production requires iron, which can be obtained from iron ore in different ways. While blast furnaces use additives and hot air to convert iron ore into iron, non-coking coal or natural gas can also be used for direct reduction of iron ore. Depending on the medium used, the process for producing direct reduced iron can be divided into a gas-based or coal-based process, for which different reactors exist. For each of these process types, Perantech offers consulting services and equipment design tailored to customer needs.