Abstract: An industrial waste management facility (IWMF) for disposing of spent potlining includes a co-current gas-fired rotary kiln for containing a molten pool of spent potlining throughout the entire length of the rotary kiln from the inlet to the outlet, an ash quencher and cooler for receiving molten residue from the discharge end of the rotary kiln, a secondary combustion chamber, and a down-draft transition chamber for channeling discharge gases from the rotary kiln to the secondary combustion chamber. Pneumatic injection slingers feed and distribute spent potlining into the inlet end of the rotary kiln. A discharge dam provides a predetermined average depth of molten bath material in the rotary kiln over its entire length. A blended ratio of comminuted materials injected through the pneumatic injection slinger feeder is adjusted and controlled in response to signals received from a radiative optical kiln bath temperature measurement system.

Abstract: An industrial waste management facility (IWMF) for disposing of spent potlining includes a co-current gas-fired rotary kiln for containing a molten pool of spent potlining throughout the entire length of the rotary kiln from the inlet to the outlet, an ash quencher and cooler for receiving molten residue from the discharge end of the rotary kiln, a secondary combustion chamber, and a down-draft transition chamber for channeling discharge gases from the rotary kiln to the secondary combustion chamber. Pneumatic injection slingers feed and distribute spent potlining into the inlet end of the rotary kiln. A discharge dam provides a predetermined average depth of molten bath material in the rotary kiln over its entire length. A blended ratio of comminuted materials injected through the pneumatic injection slinger feeder is adjusted and controlled in response to signals received from a radiative optical kiln bath temperature measurement system.

Abstract: An industrial waste management facility (IWMF) for disposing of spent potlining includes a co-current gas-fired rotary kiln for containing a molten pool of spent potlining throughout the entire length of the rotary kiln from the inlet to the outlet, an ash quencher and cooler for receiving molten residue from the discharge end of the rotary kiln, a secondary combustion chamber, and a down-draft transition chamber for channeling discharge gases from the rotary kiln to the secondary combustion chamber. Pneumatic injection slingers feed and distribute spent potlining into the inlet end of the rotary kiln. A discharge dam provides a predetermined average depth of molten bath material in the rotary kiln over its entire length. A blended ratio of comminuted materials injected through the pneumatic injection slinger feeder is adjusted and controlled in response to signals received from a radiative optical kiln bath temperature measurement system.

Abstract: A process for treating spent potlining from the electrolytic smelting of aluminum in cryolite includes incinerating the potlining to combust carbonaceous material to form an ash at a temperature low enough to maintain low fluorine vapor pressures, admixing siliceous material with the potlining either before of after the ash-forming stage, and heating the ash and siliceous material to form a glassy residue.The residue formed by the process of the present invention produces a spent potlining suitable for landfill characterized by a low leachability of fluorine in water.

Abstract: The present invention provides a process for treating spent potlining from the electrolytic smelting of aluminum in cryolite including burning the spent potlining to form an ash, mixing with a siliceous material either before or after the ash-forming step, and heating to form a residue suitable for landfill. The ash and siliceous material are mixed in a specified mole ratio of at least about 1.4 silicon to sodium. The process further includes cooling the residue rapidly.The residue formed by the process of the present invention produces a spent potlining suitable for landfill characterized by a low leachability of fluorine in water.