Waste management facility

A process for treating spent potlining containing carbon, cyanide, and fluoride, comprising:

• (a) providing spent potlining containing carbon, cyanide, and fluoride as a feed stream into a molten pool of salt bath comprising sodium, aluminum, fluoride, calcium, and silicon salts heated to a bath temperature in the range of about 1180.degree. C.-1220.degree. C. to form a molten bath over the entire length of a rotary kiln;
• (b) adding siliceous material to said spent potlining in said molten salt bath;
• (c) combusting carbon in said spent potlining in said molten salt bath at said salt bath temperature while in contact with a solid oxygenating and gasifying compound in said molten salt bath;
• and
• (d) forming a glassy residue from material exiting the discharge end of the rotary kiln.

A process for treating spent potlining from the electrolytic smelting of aluminum, comprising:

• (a) heating spent potlining in a rotary kiln vessel by admixing into a molten salt bath comprising sodium, aluminum, fluoride, calcium, and silicon salts in said rotary kiln vessel at a bath temperature in the range of about 1150.degree. C. to 1250.degree. C. while maintaining in said salt bath at a depth of at least about 24 inches in said rotary kiln over the entire length of said rotary kiln vessel;
• (b) reducing the amount of carbon content by admixing a solid oxygenating and gasifying compound consisting of calcium carbonate into said pool of spent potlining in said salt bath, thereby oxygenating and gasifying said carbon to form carbon monoxide in said pool of spent potlining in said salt bath by decomposing said calcium carbonate to carbon dioxide gas, reacting and gasifying said carbon with said carbon dioxide gas in the said salt bath to form said carbon monoxide gas;
• (c) burning said carbon monoxide gas above the molten salt bath surface;
• (d) adding siliceous material to said bath;
• and
• (e) discharging and cooling a portion of said bath to form a glassy residue suitable for landfill.