A method of manufacturing molten pig iron into an electrical smelting unit

Abstract

A method of manufacturing molten pig iron into an electrical smelting unit. The method comprises the following successive steps: providing a directly reduced iron product feeding the DRI product into the smelting unit feeding together with the DRI product, ferrous scrap having a size lower than 80 mm, melting the DRI product and the ferrous scrap to produce molten pig iron. A method to produce liquid steel from manufactured pig iron is also provided.

What is claimed is: 
     
         1 .- 9 . (canceled) 
     
     
         10 . A method of manufacturing molten pig iron in an electrical smelting unit, the method comprising the following successive steps:
 providing a directly reduced iron product;   feeding the DRI product into the smelting unit;   feeding, together with the DRI product, ferrous scrap having a size lower than 80 mm; and   melting the DRI product and the ferrous scrap to produce molten pig iron.   
     
     
         11 . The method according to  claim 10  wherein a mass fraction of ferrous scrap is from 1% to 20% by weight, based on the amount of DRI product fed in. 
     
     
         12 . The method according to  claim 10  wherein the ferrous scrap is E40 scrap. 
     
     
         13 . The method according to  claim 10  wherein the ferrous scraps are shredded before being fed to the smelting furnace. 
     
     
         14 . The method according to  claim 10  wherein a carbon-bearing material is also fed to the smelting furnace. 
     
     
         15 . The method according to  claim 14  wherein the carbon containing material is fed in an amount sufficient to reach a final carbon content of 4.0 to 4.5% in weight in the pig iron. 
     
     
         16 . The method according to  claim 10  wherein the provided DRI product is manufactured using a reducing gas containing at least 50% in volume of hydrogen. 
     
     
         17 . A method for manufacturing steel employing the method as recited in  claim 10  comprising the steps of:
 transferring the pig iron from the smelting furnace to a converter; and 
 lowering a carbon content of the pig iron to a value below 2.1 percent in weight by blowing oxygen to obtain liquid steel. 
 
     
     
         18 . The method for manufacturing steel according to  claim 17  wherein ferrous scraps are added to the pig iron in the converter, the ferrous scraps being melted.