Oxidative roasting of black dross and salt cake
AssigneeNovelis Inc.
InventorsDon Allen Doutre, Gary Richard Hay
Life of this patent
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Abstract
Salt components of dross can be extracted efficiently through evaporation. During dross treatment, temperatures can be permitted to approach or exceed the boiling point of one or more salt components of the dross, preferably in an oxidizing environment. The temperature can be held sufficiently high such that the salt content can exert an appreciable vapor pressure and can be held for a sufficient time to permit most, all, or substantially all of the salt content to evaporate and be carried away from the kiln in combustion gasses. The evaporated salt can be condensed and collected.
Claims20
A system for extracting salt from metal recycling byproducts, comprising:
- a vessel for receiving dross comprising aluminum oxides and salt;
- a heat source coupled to the vessel for heating the dross to a temperature sufficiently high to evaporate the salt as salt vapor;
- a gas outlet coupled to the vessel for conveying gas and salt vapor from the vessel;
- and
- a salt collector coupled to the gas outlet for collecting and condensing the salt vapor, wherein the salt collector is coupled to a salt source to replenish the salt source through the extraction of salt from the dross within the vessel, wherein the salt source provides salt to the vessel.
Dependencies are inferred from the claim text.