CO2-minimised pig iron production

Direct Reduction Plants DRI

The sustainable avoidance of process-related emissions in steel production can only be achieved by converting the conventional coking coal-based blast furnace process. A new technological path is the direct reduction of iron ore. The intention is to show how the successive conversion of an integrated blast furnace plant to low-CO2 steel production takes place. Depending on availability, the process can be operated with natural gas or with hydrogen based on renewable energies. The sponge iron reduced in this way is fed for processing either to an electric arc furnace or to a conventional blast furnace in which the use of the iron sponge saves the injection coal.


Kalenborn and Danieli signed a Strategic License Agreement on the field of special wear resistant, isolating refractory lining

Danieli is a global provider of iron and steel making technology. An important application is the transforming process from iron ore to direct reduced iron (DRI) which is done in the DRI reactor. In the DRI reactor one of the more sensitive parameters for maintaining product quality and performance is the discharge temperature of the iron pellets used to feed the electric arc furnace (EAF). Likewise, for feeding pellets to the hot briquetted iron (HBI) machine. The higher the temperature, the better will be HBI quality and the more energy is saved when the pellets are promoted to EAF.

Kalenborn and Danieli developed an innovative solution to be applied to the cone of the ENERGIRON plant’s reactor. This insulating system raises the temperature of the finished DRI pellets. The innovation consists of an internal lining (Patent pending) applied to the standard water- cooled steel cone. This lining comprises KALCOR (zirconia corundum) panels with microporous insulation on the back.

To avoid disruption in the normal solid flow, KALCOR has been tested in a high-temperature condition to determine the respective friction parameters and compared to the normal friction coefficient of the cold steel (normal condition). Common refractory material has too high abrasion values and cannot be used.

The cone lining can allow for an increase of the discharge temperature by 30 to 70 °C, depending on the operating plant parameters and reactor size. For every 10°C higher temperature, approx. 2.5 kWh/t of energy is saved. In a recent case, this saved about 1-2 million US dollars per year in energy costs. This innovative solution pays for itself after only a few months.

The new system causes no disruption in the reactor material flow and needs no modification of the original reactor shape. The Cone Lining technology can be applied to any existing ENERGIRON reactor due to its small thickness.

Now the two companies signed a bidirectional strategic agreement to better serve the customers seeking increased energy efficiency as well as to ensure the required levels of DRI/HBI quality and technological innovation is continuously pursued for the Energiron plants.