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JOM

, Volume 34, Issue 7, pp 54–58 | Cite as

Demagging Processes for Aluminum Alloy Scrap

  • Basant L. Tiwari
Process Metallurgy

Summary

Demagging processes can be divided into three general categories: 1) chlorination processes, in which chlorine gas is bubbled into the molten aluminum to react preferentially with magnesium which is finally removed as magnesium chloride dross; 2) solid flux processes, in which a solid-flux (AlCl3, AlF3), is mixed into the molten aluminum to react with magnesium which is again removed as chloride or fluoride dross; and 3) electrochemical processes, in which magnesium is removed as metal on the cathode by passing a current between the molten aluminum anode covered with an electrolyte and an inert cathode dipped into the electrolyte. Of the processes reviewed, chlorination methods are the most widely practiced in the industry and seem reasonably efficient. However, most of the chlorination processes appear to have emission and waste generation (MgCl2 dross) problems. The electrochemical processes have been tested only on laboratory scale so far, but they look promising for commercial use. If successfully developed, the electrochemical processes would be pollution-free, and magnesium metal would be recovered as a by-product.

Keywords

AlF3 Molten Aluminum Standard Free Energy Change Chlorination Process Electrolyte Mixture 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© The Minerals, Metals & Materials Society 1982

Authors and Affiliations

  • Basant L. Tiwari
    • 1
  1. 1.General Motors Research LaboratoriesWarren

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