Carbonaceous cathode with enhanced wettability for aluminum production

A method of preparing carbonaceous blocks for use as an improved cathode in an electrolytic cell for producing aluminum from alumina dispersed in an electrolyte wherein the cell contains molten aluminum in contact with the cathode, the cathode having improved wettability with molten aluminum, the method comprising;

• (a) providing a carbonaceous block;
• (b) providing a melt of boron oxide having an additive to facilitate impregnation of said melt into pores in said block, said additive selected from a compound of the group consisting of sodium borate, potassium borate, lithium borate, magnesium borate, and calcium borate;
• (c) immersing said carbonaceous block in said melt;
• (d) applying pressure to said melt to impregnate said melt into pores in said carbonaceous block;
• and
• (e) withdrawing said carbonaceous block from said melt, the carbonaceous block having melt intruded in said pores, the boron oxide capable of reacting said compound to form a boride to provide improved wettability of said cathode with molten aluminum.

A method of treating carbonaceous blocks for use as liner material in an aluminum producing cell using an electrolyte comprised of sodium containing salts, the block being resistant to formations or accumulations of sodium cyanide and exposed portion, said liner material resistant to air burning during operation of the cell, the method comprising:

• (a) providing a carbonaceous block for use as a liner material;
• (b) providing a boron oxide containing melt having added thereto an additive to facilitate impregnating said melt into pores in said block;
• (c) immersing said carbonaceous block in said melt;
• (d) applying pressure to said melt to impregnate pores in said carbonaceous block with said melt;
• and
• (e) withdrawing said carbonaceous block from said melt to provide a treated block having boron oxide containing melt in said pores.

A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte contained in the cell, the method comprising the steps of:

• (a) providing an electrolytic cell;
• (b) providing a carbonaceous cathode in said cell, the carbonaceous cathode comprised of bodies of carbonaceous material, said bodies treated in a boron oxide containing melt by impregnating boron oxide containing melt into pores in the carbonaceous bodies by applying pressure to the melt said melt containing an additive to facilitate impregnating melt into said pores;
• and
• (c) passing an electric current through said cell to produce aluminum at said cathode simultaneously therewith reacting boron oxide in said pores with a source of titanium to form titanium diboride to provide improved wetting of said cathode surface with molten aluminum.