Sponge iron is a high grade source of iron and steel made from recycled natural or processed iron ore without reaching the melting temperature. In this method, iron ore pellets with a grade of 67% are recovered, resulting in sponge iron (porous pellets) with Fe of about 92%. The product of the reduction unit is transferred to the steel section for direct charge of the furnace without passing the cooling part of the furnace at a temperature of about 600 ° C.
Sponge iron after melting and reduction in steel making is used in the casting process in the form of products such as slabs, billets and rebars. Today, about 5% of the world’s steel is produced from sponge iron, and this trend is on the rise.
Sponge iron comes from the direct revival of iron ore, also called DRI (Direct Reduced Iron).
Application of Sponge Iron:
The use of sponge iron in induction furnaces is one of its most important applications. It can be said that the use of sponge iron in induction furnaces is capable of replacing scrap iron by approximately 50%, and that the use of sponge iron is a major development in the continuous casting (CCM) of the steel industry.
It can be used in almost all forms of steel production. Many small and large steel plants in the country use these methods. Iran has more natural resources at its disposal for direct recovery. Sponge iron is a good substitute for iron scrap so we can supply a high percentage of the raw material needed to supply the steel melt required by the scrap iron instead of using scrap.
The direct revival of iron ore is done through gas or coal sources. The choice of direct iron ore recovery depends on the location of the manufacturing plant and the available resources. In Iran, for example, despite the abundance of gas resources, the choice of gas sources is a more reasonable choice and gas is used as a regenerative material. As you know, the use of coal resources for reclamation also causes problems with air pollution and access to the mines is not an easy task but at present the largest producer of sponge iron in the world is India which uses coal resources.