Sponge Iron

The main activity of GPIL involves production of Sponge Iron and Steel Billets. Sponge iron is manufactured through rotary kiln of 350* 1 and 500*. 3 tones capacity using coal as flue. The Flue gases available at high temperatures of around 950°C from the sponge iron kiln constitute a significant amount of heat energy. With WHRB, a modern Technology, the company produces around 0.5 million tones per annum of Sponge Iron

GPIL has achieved about 75% recovery of waste heat from flue gas of sponge iron kiln and utilization of same heat to produce steam. The steam is further utilized to generate electrical energy. In absence of the waste heat recovery steam generation system (WHRSGS), the same heat energy would have been lost in the atmosphere through stack emission of the flue gases of sponge iron kiln at GPIL’s Sponge Iron Division (SID) located within the same premises.

Coal based Sponge-iron is a metallic product produced through direct reduction of iron ore in the solid state .As such it is also known as direct reduced iron (DRI). Hematite iron ore is used for reduction. After reduction of iron ore the product resembles sponge because of pores left behind after removal of oxygen. As such it is called sponge iron. Sponge iron is a substitute of scrap in steel melting.

Although the reduction in the kiln is not direct, the CO gas reduces the oxides of hematite and the resultant DRI is in the solid form, this process is known as direct reduction process.

Coal based DRI process is mainly preferred on account of comparatively lower project cost, better ROI, crisis of good quality scrap without contamination (impurities) for steel making, international/national demand of solid metallic, availability of large reserves of iron ore & non-coking coal in India.

Properties of raw materials required for making DRI.