Composite briquettes for electric furnace charge, and in their method of use

Abstract

For use with an electric steelmaking furnace, a briquette is provided which incorporates a suitable binder, a first quantity of carbon fines, and a second quantity of a material in powdered form, the latter material being selected from the group consisiting of lime, dolime, limestone, dolomite, magnesia, magnesium carbonate, other suitable carbonates, and mixtures thereof. The second quantity being large enough to suppress the slippery nature of the carbon fines, and to density the briquette to the extent necessary to cause it to sink into the furnace melt.

1 . For addition to a charge in a steelmaking furnace, a briquette comprising: 
 a suitable binder,    a first quantity of carbon fines, and    a second quantity of a material in powdered form, selected from the group consisting of lime, dolime, magnesia, limestone, dolomite, magnesium carbonate, iron ore and mixtures thereof, said second quantity being large enough to suppress the slippery nature of the carbon fines, and to densify the briquette to the extent necessary to cause it to sink into the melt.    
   
   
       2 . A method for making a briquette for addition to the melt in a steelmaking furnace, the method comprising making a mixture of: 
 1. a suitable binder,    2. a first quantity of carbon fines, and    3. a second quantity of a material in powdered form, selected from the group consisting of lime, dolime, magnesia, limestone, dolomite, magnesium carbonate, iron ore arid mixtures thereof, said second quantity being large enough to suppress the slippery nature of the carbon fines, and to densify the briquette to the extent necessary to cause it to sink into the melt, and using a suitable mold for forming the mixture into a briquette shape.    
   
   
       3 . A method for improving the slag-covered melt in a steelmaking furnace, the furnace including a shell for holding the molten steel, and at least one charge bucket for adding, to the shell, a mix which includes at least a quantity of steel scrap, a source of carbon, and flux precursors, the method comprising the steps: 
 making a mixture of a suitable binder, a first quantity of carbon fines, and a second quantity of a material in powdered form, said material being selected from the group consisting of lime, dolime, magnesia, limestone, dolomite, magnesium carbonate, iron ore and mixtures thereof, said second quantity being large enough to suppress the slippery nature of the carbon fines, and to densify the briquette to the extent necessary to cause it to sink into the molten steel,    compressing a portion of said mixture in a mold to make a briquette therefrom,    introducing said briquette to the shell prior to adding the contents of the charge bucket to the shell.    
   
   
       4 . A method for improving the slag-covered melt in a steelmaking furnace, the furnace including a shell for holding the molten steel, and at least one charge bucket for adding, to the shell, a mix which includes at least a quantity of steel scrap, a source of carbon, and flux precursors, the method comprising the steps: 
 making a mixture of a suitable binder, a first quantity of carbon fines, and a second quantity of a material in powdered form, said material being selected from the group consisting of lime, dolime, limestone, magnesia, dolomite, magnesium carbonate, iron ore and mixtures thereof, said second quantity being large enough to suppress the slippery nature of the carbon fines, and to densify the briquette to the extent necessary to cause it to sink into the molten steel,    compressing a portion of said mixture in a mold to make a briquette therefrom, and    introducing said briquette to the shell ahead of all other materials by placing the briquette at the inside bottom of the charge bucket.    
   
   
       5 . The method claimed in  claim 4 , in which said second quantity is at least 5% of the weight of the briquette, and the density of the briquette is at least about 2.0 g/cc.  
   
   
       6 . The method claimed in  claim 5 , in which said second quantity is at least 10% of the weight of the briquette.