Composite Particle For Steel Making and Ore Refining

Abstract

Composite particles are used in combination with ore particles in an ore-refining or purification process, such as in a steel- or iron-making process. The composite particles comprise a core, which may be an aggregate of limestone, dolomite, or another ore particle. The core is surrounded by a coating layer of a metal dust and a binder. The metal dust may be iron oxide dust, which, along with limestone, is prevalent in the iron smelting process anyway. In this way, the composite particles help to recycle otherwise wasted and hazardous iron dust. The binder may be mineral clay such as bentonite, montmorillonite or kaolinite, and may comprise about 2-10% by weight of the particle.

1 . A composite particle comprising:
 a core comprising an aggregate of limestone, dolomite, or taconite;   a coating on the core, the coating comprising a metal dust and a binder material.   
     
     
         2 . The composite particle of  claim 1 , wherein the binder material is selected from Phyllosilicates. 
     
     
         3 . The composite particle of  claim 2 , wherein the binder material is selected from the kaolinite, montmorillonite/smectite/bentonite, palygorskite/attapulgite, vermiculite, and minnesotaite. 
     
     
         4 . The composite particle of  claim 1 , wherein the binder material is present in an amount from about 2% to about 10% by weight of the composite particle. 
     
     
         5 . The composite particle of  claim 4 , wherein the binder material is present at example about 5%. 
     
     
         6 . The composite particle of  claim 1 , wherein the metal dust comprises iron oxide dust. 
     
     
         7 . The composite particle of  claim 1 , wherein the core aggregate comprises from about 30 to about 90% by weight of the composite particle. 
     
     
         8 . The composite particle of  claim 1 , wherein the core is an aggregate sized to a standard size number from about 7-9. 
     
     
         9 . The composite particle of  claim 6 , wherein the iron oxide dust is present in an amount from about 20% to about 60% by weight of the composite particle. 
     
     
         10 . The composite particle of  claim 9 , wherein the iron oxide dust is present in an amount from about 30% to about 50% by weight. 
     
     
         11 . The composite particle of  claim 1 , wherein the composite particle is sized to a standard size number from about 6-9. 
     
     
         12 . An iron composition comprising coke, ore and a plurality of composite particles according to  claim 6 . 
     
     
         13 . A steel manufactured from iron made using composite particles according to  claim 6 . 
     
     
         14 . The composite particle of  claim 1 , wherein the core is a metal-ore particulate. 
     
     
         15 . The composite particle of  claim 14 , wherein the metal dust comprises a metal of the metal-ore particulate. 
     
     
         16 . The method of making iron comprising:
 smelting a mixture of iron ore, coke, and a plurality of composite particles according to  claim 6 ; and   cooling the molten iron.   
     
     
         17 . A method of recycling iron oxide waste dust from a steel- or iron-making operation, the method comprising:
 mixing the iron oxide dust with a mineral clay binder to form a coating;   applying the coating as a layer on a limestone or dolomite aggregate core to form a composite particle; and   re-smelting the composite particle with ore and coke.   
     
     
         18 . A method of smelting a metal alloy comprising:
 smelting a mixture of at least one metal ore and a plurality of composite particles according to  claim 1 , the metal dust of the composite particle being a component of the metal alloy; and   cooling the molten metal.