SPONGE IRON UNIT

Steel Exchange India Limited is having a Sponge Iron manufacturing unit in technical collaboration with world renowned M/s Mannesmann Demag of Germany (CODIR Process). With an installed capacity of 2x350TPD and can able to produce Sponge Iron of 0.225 Million Tons per Annum
1. The main raw materials used for the production of sponge iron is Iron ore which is purchased and transported from NMDC through railway wagons. Alternatively DRI grade Pellets which are produced from iron ore fines can also be purchased and utilized instead of Iron Ore.
2. Coal is another main raw material for process of Sponge Iron and both Indian Coals and Imported Coals can be used for the process. Indian Coals are purchased and Transported through Railway Wagons and Australian or South African Coals are imported and shipped through Vizag Sea Port.
3. The raw materials are prepared in the raw material preparation plant to the required size and are stored in separate storage bins. Iron Ore and Coal are drawn with the help of weigh feeders in the required quantity and proportion and fed on to common conveyor. These raw materials enter into the rotary kiln through a feed chute.
4. The rotary kiln is 70 meters in length and 4.4 meter in diameter. This kiln is provided inside with 250mm thick refractory lining. This kiln is having 3 support rollers and a dual drive with two 155 KW D.C motors. The kiln inclined at 2.5%.The kiln is provided with seven shell air fans and air tubes for supplying of air inside the kiln.
5. The Iron ore and coal fed into the kiln are initially pre-heated with the liberation of heat from the volatiles from the coal in the first 1/3rd of the kiln. Then the reduction starts and the iron oxides are reduced to metallic iron. The following chemical reactions take place inside the kiln.
a. C + 02 = CO2
b. CO2 + C = 2CO
c. 3Fe2O3 + CO = 2Fe3O4+CO2
d. Fe3O4 + CO = 3FeO + CO2
e. Fe O + CO = Fe + CO2
6. The product i.e. Sponge Iron and semi burnt coal are discharged from the kiln through a rotary cooler. The cooler is 12M in length and water is sprayed directly as well as indirectly for cooling the material. The material is cooled down to 100oC and fed to magnetic separator for separating the sponge iron and non-magnetic (char). The Sponge Iron is conveyed to the Storage Silos for dispatch.
7. When the material is travelling downward in the kiln, the hot gases travel in opposite direction. These gases are utilized for power generation through WHRB. First they enter into the dust settling chamber, where heavier particles settle down the gases then enter into after burning chamber, where air is supplied for burning carbon monoxide to carbon dioxide if any present in the gasses. Then the gasses enter into waste heat recovery boiler (WHRB), then economizer, where the gasses are cooled down to below 180o C. These gasses pass through ESP for eliminating dust particles and the gases are emission through chimney and ID Fan.