SPONGE IRON

Steel, because of its versatile properties and its recycling possibilities, is the basic  material for sustained development in modern industrial society. It enjoys a broad range of uses in almost all important sectors of  industry, such as apparatus and machinery manufacture, bridge biulding, steel-framed building construction, power and environmental engineering,

transportation, and the packaging industry.

     Steel making is a complicated 

     processes involving many stages 

     and yielding thousand of by-

     products.  

 Steel can be  produced either from 

 steel scrap or sponge iron. 

 The process used for the manufacturing of iron & steel has 

 a bearing on the cost of production & the quality of

 the steel produced.

 The Iron Making process

 The first step in the steel making process is producing

 iron from iron ore.  

 The process is called the iron-making process.

 Three different methods can be used  for the production

 of iron from Iron ore.

 They are:

1.    Coke-Ovens -Sinter-Blast Furnace (BF) Route

2.    Direct Reduction Technique

3.    Smelting Reduction Technologies

The Steel Making Process

The second stage in iron and steel making is the steel making process. Generally two types of techniques are adopted for steel making. They are the Basic Oxygen Furnace (BOF) type and Electric arc furnace (EAF) type.

Basic Oxygen Furnace Technique (BOF)

The Basic oxygen furnace is used for producing steel from the refined iron. Hot metal from the Blast furnace, which is a pear shaped furnace or reduced iron from the smelting plant is fed in to the Basic Oxygen Furnace (BOF) after pre-treatment to remove undesired elements like sulfur, silicon or phosphorous. Molten Steel in liquid form is obtained. Impurities go out in gaseous form and as slag. The liquid steel produced here is called crude steel.

Electric Arc Furnace (EAF)

Steel scrap or Pig iron or Sponge iron is used as the raw material in this process. Here the raw material is melted using heat generated with the aid of an electric arc produced by graphite electrodes. Here again the output is crude steel. The crude steel produced from the above said processes are either used for producing ingots or fed in the continuous casting process cycle. Ingot-definition- Molten steel cast in vertical cast iron moulds intended for rolling after heating in two stages i.e. in a primary mill and then in a finishing mill.