Refractory components

Abstract

A refractory component is provided for use in a metal producing or refining process in which the component is at least partially immersed in molten metal. The component including a graphite member ( 2 ) and a refractory sleeve ( 10 ) that covers at least part of the graphite member. A recess ( 12 ) is provided in the surface of the graphite member ( 2 ) and the refractory sleeve ( 10 ) is located in the recess.

1 . A refractory component for use in a metal producing or refining process in which the component is at least partially immersed in molten metal, the component including a graphite member and a refractory sleeve that covers at least part of the graphite member, characterised in that a recess is provided in the surface of the graphite member and the refractory sleeve is located in the recess.  
     
     
         2 . A refractory component according to  claim 1 , characterised in that the refractory sleeve covers the region of the graphite member that in use passes through the surface of the molten metal.  
     
     
         3 . A refractory component according to  claim 2 , characterised in that the refractory sleeve is of a length such that, in use, it extends above and below the surface of the molten metal by a distance in the range 50-300 mm, preferably 100-150 mm.  
     
     
         4 . A refractory component according to any one of the preceding claims, characterised in that the refractory sleeve is cast in situ in the recess provided in the surface of the graphite member.  
     
     
         5 . A refractory component according to any one of the preceding claims, characterised in that the external surface of the refractory sleeve is substantially level with the external surface of the graphite member.  
     
     
         6 . A refractory component according to  claim 5 , characterised in that the recess has a depth in the range 1-30 mm, preferably 8 mm.  
     
     
         7 . A refractory component according to any one of  claims 1  to  4 , characterised in that the external surface of the refractory sleeve is raised above the external surface of the graphite member.  
     
     
         8 . A refractory component according to  claim 7 , characterised in that the recess has a depth in the range 1-30 mm. preferably 3 mm.  
     
     
         9 . A refractory component according to any one of the preceding claims, characterised in that the recess has circumferential walls that are inclined towards one another.  
     
     
         10 . A refractory component according to  claim 9 , characterised in that the circumferential walls that are inclined relative to the surface of the graphite member at an angle in the range 20-89°, preferably approximately 60°.  
     
     
         11 . A refractory component according to any one of the preceding claims, characterised in that the sleeve has a thickness in the range 1-25 mm, preferably 7 mm.  
     
     
         12 . A refractory component according to any one of the preceding claims, including an expansion gasket between the refractory sleeve and the graphite member.  
     
     
         13 . A refractory component according to  claim 12 , characterised in that the expansion gasket has a thickness in the range 0.5-5 mm, preferably 1 mm.  
     
     
         14 . A refractory component according to  claim 12  or  claim 13 , characterised in that the expansion gasket includes a layer of ceramic paper.  
     
     
         15 . A refractory component according to any one of the preceding claims, in which the refractory sleeve is made of a ceramic material.  
     
     
         16 . A refractory component according to  claim 15 , in which the refractory sleeve is made off used silica, alumina, silicon carbide, silicon nitride, silicon aluminium oxy-nitride, Mullite, zircon or zirconia, or a combination thereof.  
     
     
         17 . A refractory component according to any one of the preceding claims, wherein the component comprises a substantially cylindrical shaft.  
     
     
         18 . A refractory component according to  claim 17 , in which the shaft has a diameter in the range 30-200 mm, preferably approximately 75 mm.  
     
     
         19 . A refractory component according to  claim 17  or  claim 18 , in which the shaft has a length in the range 0.5-2.0 m, preferably approximately 1.0-1.3 m.  
     
     
         20 . A refractory component according to any one of  claims 17  to  19 , in which the shaft is hollow.  
     
     
         21 . A refractory component according to any one of the preceding claims, for use in a process for producing or refining non-ferrous metals.  
     
     
         22 . A refractory component according to  claim 21 , for use in a process for producing or refining aluminium and aluminium alloys.  
     
     
         23 . A method of making a refractory component for use in a metal producing or refining process in which the component is at least partially immersed in molten metal, the refractory component including a graphite member and a refractory sleeve that covers at least part of the graphite member, characterised in that a recess is formed in the surface of the graphite member and the refractory sleeve is cast in the recess.  
     
     
         24 . A method according to  claim 23 , in which the refractory sleeve is cast in situ in the recess.  
     
     
         25 . A method according to  claim 23  or  claim 24 , in which the graphite member is shaped on a lathe, and the recess is formed on the surface of the graphite member during the shaping operation.  
     
     
         26 . A method according to any one of  claims 23  to  25 , in which a mould is placed over the recess and a refractory material is injected into the recess beneath the mould.  
     
     
         27 . A method according to any one of  claims 23  to  26 , in which the refractory sleeve is fired on the graphite member.