Sponge Iron Making

The process of sponge iron manufacturing involves removal of oxygen from iron ore. When that happens, the departing oxygen causes micro pores 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.
 

The Main Raw Material are Primary ore Secondary Iron Ore (Magnetite or Hematite),  Iron sand also can be used but it should be a Pellet first. Beside that Non Cooking Coal for reduction and sometimes dolomite or Lime is needed to fix the Sulfur and or bacisity.

Fig 1. Example for Specification of Iron Ore

 

 

Fig 2. Rotary Kiln Cross Section

 

Coal based Direct reduction process is classified based on the reducing agent namely solid. Most solid reduction process use non-coking coal as reducing agent due to abundantly available non-coking coal. The process proposed to be adopted is the rotary kiln proposes using Non-coking coal and iron ore. Iron are undergoes the following reduction reaction in all the processes.

 

Based on Fig 3. seen that the reaction start at Temperature around 700 oC with 60% of CO at 1 atm. But Normally, the process is done at temperature 900-1100 oC.

 

Fig 3. Iron and Boudouard reaction Diagram

 

 

After processed in rotary kiln, the product sponge iron come to the water cooled cooler where its temperature reaches to 80 to 100°C. The Product is conveyed to the product separation and storage building.

 

 

 

Fig 4. Example of Spong Iron Specification

 

 



The Example of the Complete Flowsheet can be seen as figure 5.

 

 

Fig. 5 Process Flowsheet