초록 ▼

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

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.

대표청구항 ▼

A process for treating spent potlining from the electrolytic smelting of aluminum in cryolite comprising: (a) heating spent potlining to burn carbonaceous material at a temperature low enough to maintain a low fluorine vapor pressure and form an ash; (b) admixing siliceous material either before or

A process for treating spent potlining from the electrolytic smelting of aluminum in cryolite comprising: (a) heating spent potlining to burn carbonaceous material at a temperature low enough to maintain a low fluorine vapor pressure and form an ash; (b) admixing siliceous material either before or after said ash-forming step; (c) heating said ash and siliceous material to form a glassy residue suitable for landfill; and (d) cooling said residue rapidly. A process for providing a spent potlining product characterized by a low leachability of fluorine in water comprising: (a) incinerating spent potlining at a temperature in the range of about 800-850°C. to form an ash; (b) mixing said ash with siliceous material; (c) heating to form a glassy residue suitable for landfill; and (d) cooling said residue rapidly.