Process for recovery of aluminum using high purity salt aluminum flux

A process for the recovery of aluminum from scrap aluminum and for increasing the coalescence of aluminum during the process, the process comprising:

• mixing the scrap aluminum in a solid or molten form and a salt flux composition in a solid or molten form and heating solids if they are present to provide a molten mixture, the salt flux composition consisting essentially of:
• at least about 90 weight percent of an alkali metal salt selected from the group consisting of NaCl, KCl and mixtures thereof;
• at least about 0.2 weight percent alkaline agent, based upon the weight of the salt flux composition, the alkaline agent being selected from the group consisting of Na2CO3, NaOH, KOH, K2CO3 and mixtures thereof;
• and
• at least about 3 weight percent fluoride source, based upon the weight of the salt flux composition, the fluoride source being selected from the group consisting of MF, CaF2, MAlF4, M3AlF6 and mixtures thereof where M is sodium or potassium, the alkali metal salt, the alkaline agent and fluoride source each being in relative amounts effective for improving the recovery of aluminum in the process when the salt flux composition is mixed with molten aluminum and the alkali metal salt is present at a level of at least about 1 weight percent based upon the weight of the molten aluminum as compared to a process which utilizes a salt flux composition consisting essentially of a high purity alkali metal salt without the alkaline agent and fluoride source.

A process for the recovery of aluminum from scrap aluminum and to increase the coalescence of molten aluminum during the process, the process comprising:

• mixing the scrap aluminum in a solid or molten form and a salt flux composition in a solid or molten form and heating solids if they are present to provide a molten mixture, the salt flux composition comprising:
• at least about 90 weight percent, based upon the weight of the salt flux composition, of a high purity alkali metal salt selected from the group consisting of NaCl, KCl and mixtures thereof;
• at least about 0.2 weight percent, based upon the weight of the salt flux composition of an alkaline agent;
• and
• from about 3 to about 7 weight, percent, based upon the weight of the salt flux composition, of a fluoride source,
• the alkaline agent and fluoride source each in amounts effective for improving the recovery of aluminum in the process when the salt flux composition is mixed with molten aluminum and the alkali metal salt is present at a level of at least about 1 weight percent based upon the weight of the molten aluminum as compared to a process which utilizes a salt flux composition consisting essentially of a high purity alkali metal salt without the alkaline agent and fluoride source.