This investigation revealed that the thermodynamic reactions that occur during Al remelting may lead to material losses for specific elements and circumstances. Mg losses as a result of oxidation are thermodynamically favorable to occur, but are limited by the exposure of Mg particulates to the oxygen atmosphere. Volatilization of Mn may also contribute to material losses, which is also limited by the materials exposure to the oxygen atmosphere. The relatively short melt processing times and the protective dross layer may largely limit the oxidation of Mg and volatilization of Mn. Material losses from the formation of second phase precipitates were shown to be exclusively a concern for the formation of second phase particles with densities less than Al. The low density of Al severely limited the potential compounds that could contribute to material losses. A study on the formation of pure Si second phase particles demonstrated that the particles would need to be approximately 40 µm to reach the dross under normal processing conditions. Particles of other compositions are expected to require much larger melting periods to reach the dross because the low density of Si allows it to serve as the lower bound of the time requirement. Dross chemistry was shown to influence the material yield. Batch planners should consider which fluxes are implemented in the modeled process to accurately predict batch plans. Aluminum recycling batch planners should also be prepared to update their batch plans as the popularity of chemically reactive fluxes and dross reprocessing for material recovery increases. Better management methods for compositional uncertainty resulting from thermodynamic effects will allow creation of batch plans for Al alloy products that increase incorporation of secondary metals, thereby reducing energy consumption in Al production while simultaneously providing economic benefits.
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