Injection lance

Abstract

An injection lance to stir, trim and rinse a molten metal, such as liquid steel. A gas, or a gas and one or more powdered/granular metallurgical agents, may be introduced into the molten metal through the injection lance. The injection lance includes a plurality of interconnecting components. The components include at least one body section and one end section. Each section includes a center pipe and a refractory shell surrounding the center pipe. The body section(s) and end section provide a conduit for the gas or gas plus powdered/granular metallurgical agents. In a preferred embodiment, at least a portion of one of the refractory shells is made of a refractory composition that is isopressed around the center pipe.

1 . An injection lance for use in a metallurgical operation, the injection lance comprising: 
 at least one body section having a first center pipe and a first refractory shell surrounding the first center pipe;    an end section having a second center pipe and a second refractory shell, said end section joined to at least one of said body sections, wherein at least a portion of at least one of the first and second refractory shells is formed of a refractory composition that is isopressed.    
   
   
       2 . An injection lance according to  claim 1 , wherein said refractory composition includes carbon.  
   
   
       3 . An injection lance according to  claim 2 , wherein said carbon is 1% to 25% of said refractory composition, by weight.  
   
   
       4 . An injection lance according to  claim 2 , wherein said carbon is selected form the group consisting of: carbon black, graphite, silicon carbide, powdered pitches and combinations thereof.  
   
   
       5 . An injection lance according to  claim 1 , wherein said refractory composition includes a refractory material selected from the group consisting of: alumina (Al 2 O 3 ), magnesium oxide (MgO), silica (SiO 2 ), zirconium oxide (ZrO 2 ), spinel (MgO.Al 2 O 3 ) and combinations thereof.  
   
   
       6 . An injection lance according to  claim 5 , wherein said refractory material is 65% to 99% of said refractory composition, by weight.  
   
   
       7 . An injection lance according to  claim 5 , wherein said alumina is selected from the group consisting of: tabular alumina, white fused alumina, brown fused alumina, bauxite and combinations thereof.  
   
   
       8 . An injection lance according to  claim 1 , wherein said refractory composition includes an antioxidant.  
   
   
       9 . An injection lance according to  claim 8 , wherein said antioxidant is 0% to 15% of said refractory composition, by weight.  
   
   
       10 . An injection lance according to  claim 8 , wherein said antioxidant is selected from the group consisting of: magnesium, aluminum, silicon, boron carbide, elemental boron, other boron-containing compounds, and combinations thereof.  
   
   
       11 . An injection lance according to  claim 1 , wherein said refractory composition includes a resin binder.  
   
   
       12 . An injection lance according to  claim 11 , wherein said resin binder is selected from the group consisting of: phenolic resin, resorcinol-formaldehyde resin, epoxy resin, polyvinyl chloride, furan resins, urea-formaldehyde resins, polyurethane resins, silicone resins, polyacrylic resins, vinylacetate resins, polyamine resins, polybutadiene resins and combinations thereof.  
   
   
       13 . An injection lance according to  claim 1 , wherein said refractory composition includes an additive selected from the group consisting of: metallic and non-oxide powders and aggregates, and metal, organic and carbon fibers.  
   
   
       14 . An injection lance according to  claim 1 , wherein said injection lance includes a plurality of body sections, wherein said plurality of body sections are joined together.  
   
   
       15 . An injection lance according to  claim 1 , wherein said end section includes a nozzle assembly comprising a porous nozzle tip.  
   
   
       16 . An injection lance according to  claim 15 , wherein said nozzle assembly further comprises a pipe extending from said porous nozzle tip, said second center pipe dimensioned to receive said pipe.  
   
   
       17 . An injection lance according to  claim 15 , wherein said end section includes a plurality of rods radially disposed around said second center pipe, each said rod including a portion spaced from said second center pipe, said rods dimensioned to capture said porous nozzle tip.  
   
   
       18 . An injection lance according to  claim 1 , wherein said end section has an opening defining an open-ended tip.  
   
   
       19 . An injection lance according to  claim 1 , wherein at least a portion of at least one of the first and second refractory shells is formed of a castable refractory material.