Application of the Aluminothermic Reduction Process for Magnesium Removal in Aluminum Scrap

Abstract

Magnesium is considered as impurity element in aluminum recycled for obtaining some cast alloys, with low concentration Mg, because at 0.1 wt% results in fragility, fractures, and defects. This research applies the aluminothermic reduction process to decrease magnesium content in aluminum cans by adding ZnO, to produce reaction products solid-state (Al2O3, MgO and MgAl2O4), and there is a possibility to obtain Al-Zn alloy. The conditions of the process were, melting temperature (750, 800, 850°C) and stirring velocity (200, 250, 300 rpm). The Mg and Zn contents were measured for chemical analysis and scrap generated from every process was analyzed by X-ray diffraction. The results show how the aluminothermic reduction decreased Mg from 0.93 to 0.06 wt% and increased zinc up to 5.52wt % in the molten metal. Therefore, this process can be used to remove Mg and can also prevent the generation of polluting gases into the environment.