Slag Conditioner for Electric Arc Furnace Steel Production

Abstract

A slag conditioner for electric arc furnace steel production comprising a carbonate-containing material with the balance being a reducing agent that comprises a reducing element that is easily oxidized in an exothermic reaction. The slag conditioner may further include carbonaceous material and/or an MgO-containing material. The slag conditioners may be in particulate, pellet, or briquette form. Also, a method of conditioning the slag in an electric arc furnace where steel in being produced, the method comprising introducing the particulate or pellet slag conditioners into the slag or into an interface between the slag and the molten metal or charging the briquette slag conditioners into the top of the furnace.

The invention claimed is: 
     
         1 . A slag conditioner for electric arc furnace steel production comprising:
 50-90 wt. % of a carbonate-containing material with the balance being a reducing agent that comprises a reducing element that is easily oxidized in an exothermic reaction,   wherein the weight ratio of CO 3  to the reducing element (CO 3 :reducing element) for the slag conditioner is 3-20.   
     
     
         2 . The slag conditioner of  claim 1 , wherein the carbonate-containing material is one or more material selected from the group consisting of dolomite and limestone. 
     
     
         3 . The slag conditioner of  claim 1 , wherein the reducing element is selected from the group consisting of silicon and aluminum. 
     
     
         4 . The slag conditioner of  claim 1 , further comprising 5-25 wt. % of an MgO-containing material, wherein the CO 3  to MgO (CO 3 :MgO) weight ratio for the slag conditioner is 1-15. 
     
     
         5 . The slag conditioner of  claim 4 , wherein at least 50% of the MgO in the MgO-containing material is periclase. 
     
     
         6 . The slag conditioner of  claim 1 , wherein the slag conditioner is a particulate comprising particles of the carbonate-containing material mixed with particles of the reducing agent or is a pellet comprising particles of the carbonate-containing material mixed with particles of the reducing agent. 
     
     
         7 . The slag conditioner of  claim 1 , wherein the slag conditioner is a briquette. 
     
     
         8 . A method of conditioning the slag in an electric arc furnace where steel is being produced, the method comprising introducing the slag conditioner of  claim 6  into the slag or into an interface between the slag and the molten metal. 
     
     
         9 . A method of conditioning the slag in an electric arc furnace where steel is being produced, the method comprising charging the slag conditioner of  claim 7  into the top of the furnace. 
     
     
         10 . A slag conditioner for electric arc furnace steel production comprising a carbonate-containing material, a carbonaceous material, and a reducing agent that comprises a reducing element that is easily oxidized in an exothermic reaction,
 wherein the slag conditioner comprises 10-40 wt. % of the carbonate-containing material, 8-87 wt. % of the carbonaceous material, and the balance is the reducing agent, and   the weight ratio of CO 3  to the reducing element (CO 3 :reducing element) is 3-20 and the weight ratio of CO 3  to the carbon provided by the carbonaceous material (CO 3 :C) is 0.1-5.   
     
     
         11 . The slag conditioner of  claim 10 , wherein the carbonate-containing material is one or more material selected from the group consisting of dolomite and limestone. 
     
     
         12 . The slag conditioner of  claim 10 , wherein the reducing element is selected from the group consisting of silicon and aluminum. 
     
     
         13 . The slag conditioner of  claim 10 , wherein the carbonaceous material is one or more material selected from the group consisting of anthracite coal, semi-anthracite coal, bituminous coal, natural graphite, synthetic graphite, petroleum coke, metallurgical coke, spent EAF electrodes, spent carbon anodes, and carbon black. 
     
     
         14 . The slag conditioner of  claim 10 , further comprising 5-25 wt. % of an MgO-containing material, wherein the CO 3  to MgO (CO 3 :MgO) weight ratio for the slag conditioner is 0.1-10. 
     
     
         15 . The slag conditioner of  claim 14 , wherein at least 50% of the MgO in the MgO-containing material is periclase. 
     
     
         16 . The slag conditioner of  claim 10 , wherein the slag conditioner is a particulate comprising particles of the carbonate-containing material, the carbonaceous material, and the reducing agent or is a pellet comprising particles of the carbonate-containing material, the carbonaceous material, and the reducing agent. 
     
     
         17 . The slag conditioner of  claim 10 , wherein the slag conditioner is a briquette. 
     
     
         18 . A method of conditioning the slag in an electric arc furnace where steel is being produced, the method comprising introducing the slag conditioner of  claim 16  into the slag or into an interface between the slag and the molten metal. 
     
     
         19 . A method of conditioning the slag in an electric arc furnace where steel is being produced, the method comprising charging the slag conditioner of  claim 17  into the top of the furnace.