Removing of Mg in Al-Mg Alloy by Calcined Powder from Used Dry-Cell Batteries

Abstract

  To reduce Mg content in Al-Mg alloy for aluminum recycling, calcined powder made from used dry-cell battery was reacted with the liquid aluminum alloy. The powder was found to consist of ZnMn₂O₄, MnO, ZnO, and carbon by XRD analysis. After the reaction between pellets of the powder and the alloy in liquid at 973 K or 1073 K for 3.6×10³ s, Mg content in the alloy decreased from 4.0 to 2.3 mass%. And at the same time, contents of Mn and Zn in the alloy increased from 0 to about 0.2 and 0.1 mass%, respectively. During the reaction, metallic Mg in the liquid Al-Mg alloy was found to move in to the pellets to form MgO. It may be assumed that an exchange reaction between Zn²⁺ at ZnO in the pellets and Mg²⁺ from the liquid alloy takes place.