1. Introduction

Aluminum alloys are a material required mainly in aerospace and automotive sectors [1]. This has contributed to an increased demand for aluminum and therefore the search for new forms of production. Recycling products have been considered as an alternative source of raw material; however, the secondary aluminum industry is facing up the implementation of different processes to return these materials to everyday life, modifying the mechanical properties according to the type of application to which it will be destined. For this reason, the trend toward metal recycling has increased significantly in recent years, not only because of economic aspects, but also because of the positive impacts on the environment [2–4]. Nevertheless, there is still a lot of development to be done because the

industry demands high-quality materials regardless of their origin. For cast alloys, the aluminum scrap must be carefully selected because the impurities degrade the material form that decrease the mechanical properties of the alloys. The most common impurities in recycled alloys are Fe, Si, and Mg in the automotive industry [5, 6]. Different refining processes are used for the removal of magnesium, such as Cl2 or Fl2 gas injection, but the processes produce great amounts of HCl gas. Many countries have been forced to regulate this process, while others have banned it due to the high amount of polluting gases that are emitted into the environment [7–9]. Right to this, the industry needs to find new technologies to reduce the magnesium in aluminum scraps, such as the process of compound separation methods or aluminothermic reduction with different oxides [10–13].

This work uses the aluminothermic reduction process with ZnO powder, with the objective of removing the magnesium content in aluminum molten scrap and adding zinc for production aluminum alloys type 700. By implementing this technology, gases can be considerably reduced because the reactions produced in the metal bath can lead to the formation of magnesium products in a solid-state and to be easily removed with the slag.
