What is Sponge Iron?

About Sponge Iron:

• Direct-reduced iron (DRI), also called sponge iron, is produced from the direct reduction of iron ore (in the form of lumps, pellets, or fines) by a reducing gas produced from natural gas or coal. 
• The reducing gas is a mixture, the majority of which is hydrogen (H2) and carbon monoxide (CO), which act as reducing agents. 
• This process of reducing the iron ore in solid form by reducing gases is called direct reduction.
• Why is it called Sponge Iron?
  • The process of sponge iron manufacturing involves the removal of oxygen from iron ore.
  • When that happens, the departing oxygen causes micropores in the ore body, turning it porous.
  • When the eventual product is observed under a microscope, it resembles a honeycomb structure, which looks spongy in texture. Hence the name sponge iron.
• Significance:
  • Its significance in the steel industry ranges from an alternative to scrap to boosting furnace efficiency. 
  • It is used as a substitute for scrap in induction and electrical furnaces.
  • The reason for this is that melting scrap is expensive and also in short supply, so sponge iron is the perfect alternative when it comes to using it in the production of high-quality steel.
  • It is an iron source that is relatively uniform in composition, and virtually free from tramp elements.
• India is the world's largest producer of sponge iron, most of which is produced primarily through the coal-based method of production. India produces 20% of the world’s sponge iron with over 200 plants.