Abstract: A method of reducing the airburning tendency of petroleum coke and carbon anodes made therefrom includes calcining the coke and spray quenching the calcined coke with an additive-containing water. The additive includes an effective amount of a compound of aluminum which is soluble in the quench water. The additive is deposited on the quenched coke product surface and protects the coke from oxidation or premature combustion when in contact with the atmosphere at high temperatures. The additive-coated coke can then be formed into an anode which also has a reduced tendency to airburn during use in a high temperature environment such as an aluminum reduction cell or an electric furnace operation.

Abstract: A method is disclosed for detoxification of aluminum spent potliner by thermal treatment in a rotary kiln while blended with limestone and metal silicates to destroy cyanides and convert the soluble fluoride salts to relatively insoluble calcium fluoride and fluoride-bearing minerals, quenching the hot kiln discharge with an aqueous lime slurry to convert residual soluble fluoride salts on the particle surfaces to an insoluble form, and treating aqueous landfill runoff and capture with lime or limestone and recycling the treated water to the process. The treated material is suitable for landfilling in a non-hazardous waste landfill or marketing as a raw material. Air emissions are innocuous and there is no aqueous discharge.

Abstract: A method is disclosed for recycling spent potliner carbon from an aluminum reduction cell. The spent potliner is treated so as to avoid the cracking problem normally seen when the potliner is used in substantial amounts in Soderberg anodes.