Stabilization of fluorides of spent potlining by chemical dispersion

摘要

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.