Cathode for aluminum production and electrolytic cell

Abstract

The present invention provides an improved TiB 2 cathode for use in aluminum production cells for the electrolysis of alumina dissolved in a cryolite-based molten electrolyte and an improved electrolytic cell for producing aluminum. The cathode is a monolithic, porous, TiB 2 body having a continuous porosity and interconnected pores substantially throughout.

What is claimed is:  
     
         1 . An improved TiB 2  cathode for use in aluminum production cells for the electrolysis of alumina dissolved in a cryolite-based molten electrolyte, which comprises: 
 a monolithic, porous, TiB 2  body having a continuous porosity and interconnected pores substantially throughout, prepared by compacting at least one of titanium and titanium hydride powder to form a porous preform, followed by boriding, said body having improved thermal shock resistance and good wettability towards molten aluminum.    
     
     
         2 . An improved TiB 2  according to  claim 1 , wherein the powder is sintered at least in part.  
     
     
         3 . An improved TiB 2  according to  claim 1 , wherein said body comprises compacted powder reacted to form a TiB 2  body throughout.  
     
     
         4 . An improved TiB 2  according to  claim 1 , wherein said porous TiB 2  body includes carbon intermixed therein.  
     
     
         5 . An improved TiB 2  according to  claim 4 , wherein the carbon is at least in part bonded to the compacted powder.  
     
     
         6 . An improved TiB 2  according to  claim 1 , wherein the TiB 2  body is a composite material.  
     
     
         7 . An improved TiB 2  according to  claim 1 , wherein each titanium particle is essentially converted to TiB 2 .  
     
     
         8 . An improved electrolytic cell for producing aluminum by electrolyzing alumina dissolved in a cryolite-based electrolyte, comprising an anode and a cathode in contact with the aluminum product, wherein: 
 said cathode comprises a monolithic, porous, TiB 2  body having a continuous porosity and interconnected pores substantially throughout, prepared by compacting at least one of titanium and titanium hydride powder to form a porous preform, followed by boriding, said body having improved thermal shock resistance and good wettability towards molten aluminum.    
     
     
         9 . An improved electrolytic cell according to  claim 8 , wherein said cathode is immersed in said electrolyte and in contact with the liquid aluminum pad.  
     
     
         10 . An improved electrolytic cell according to  claim 9 , wherein the anode and cathode face each other and are spaced closer to each other than the usual ACD for the carbon anode and aluminum pad cathode.  
     
     
         11 . An improved electrolytic cell according to  claim 8 , wherein each titanium particle is essentially converted to TiB 2 .  
     
     
         12 . An improved electrolytic cell according to  claim 8 , wherein said porous body comprises compacted powder reacted to form a TiB 2  body throughout.  
     
     
         13 . An improved electrolytic cell according to  claim 8 , wherein said porous TiB 2  body includes carbon intermixed therein.  
     
     
         14 . An improved electrolytic cell according to  claim 13 , wherein said carbon is at least in part bonded to the compacted powder.  
     
     
         15 . An improved electrolytic cell according to  claim 13 , wherein said carbon is intermixed prior to boriding.  
     
     
         16 . An improved electrolytic cell according to  claim 15 , wherein said carbon is intermixed following boriding.  
     
     
         17 . An improved electrolytic cell according to  claim 9 , wherein the anode is a carbon anode.  
     
     
         18 . An improved electrolytic cell according to  claim 9 , wherein the cell comprises interdigitated vertical inert anodes and inert cathodes.  
     
     
         19 . An improved electrolytic cell according to  claim 9 , wherein the TiB 2  body is a composite material.