Aluminum scrap recovery by inductively moving molten metal
AssigneeAluminum Company of America
InventorsThomas J. Robare, Jeffrey B. Gorss, Robert A. Gutknecht, J. Richard Semk
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Abstract
A method for removing dissolved alkali metals and alkaline earth metals from aluminum is disclosed. The method comprises providing a body of molten aluminum containing the alkali metal and alkaline earth metals in a container and inductively moving the molten aluminum in upper regions of the body in a generally downward direction at outward regions of the body and in a generally upward direction in inner regions of the body. Fluoride values are added to the body to react with the alkali metals or alkaline earth metals.
Claims20
A method for removing alkali metals and alkaline earth metals from aluminum comprising:
- (a) providing a body of molten aluminum containing said alkali metal and alkaline earth metals in a container;
- (b) inductively moving said molten aluminum in upper regions of said body in a generally downward direction at outward regions of the body and in a generally upward direction in inner regions of the body;
- and
- (c) adding fluoride values, selected from HF, SF.sub.6, NaF, KF, AlF.sub.3, CaF.sub.2, KAlF.sub.2, CaAlF.sub.5 and NaAlF.sub.4, to said body to react with said alkali metals or alkaline earth metals.
A method for removing dissolved alkali metals and alkaline earth metals from aluminum comprising:
- (a) providing a body of molten aluminum containing said alkali metal and alkaline earth metals in a container;
- (b) inductively moving said molten aluminum in upper regions of said body in a generally downward direction at outward regions of the body and in a generally upward direction in inner regions of the body;
- (c) adding fluoride values, selected from HF, SF.sub.6, NaF, KF, AlF.sub.3, CaF.sub.2, KAlF.sub.2, CaAlF.sub.5 and NaAlF.sub.4, to said body to react with said alkali metals or alkaline earth metals;
- (d) maintaining movement of said body until said alkali metals or alkaline earth metals are reacted to leave only a low level thereof dissolved in the molten aluminum;
- and
- (e) separating said reacted alkali metals and alkaline earth metals from said molten aluminum.
A method for removing dissolved alkali metals and alkaline earth metals from aluminum comprising:
- (a) providing a body of molten aluminum containing said alkali metal and alkaline earth metals in a container;
- (b) inductively moving said molten aluminum in upper regions of said body in a generally downward direction at outward regions of the body and in a generally upward direction in inner regions of the body;
- and
- (c) adding an aluminum fluoride material to said body to react with said alkali metals or alkaline earth metals to provide reacted material, the aluminum fluoride material being added in substantially stoichiometric amounts based on the amount of alkali metal or alkaline earth metal in the melt;
- (d) removing reacted material from said body;
- (e) after removing reacted material, adding further aluminum fluoride to said body to react with residual alkali metals or alkaline earth metals to provide reacted material, the aluminum fluoride being added in a stoichiometric ratio range of 0.5:1 to 5:1 based on the amount of alkaline metal or alkaline earth metal in the melt;
- and
- (f) separating reacted alkali metal and alkaline earth metals from the molten aluminum.
Dependencies are inferred from the claim text.