Green Aluminum: Trends and Prospects

Abstract

Due to its properties aluminum is a vital resource for circular economy and zero waste technologies, recycling and sustainability. Recycling aluminum provides an opportunity to decrease carbon dioxide emissions by replacing primary aluminum. Recycling of aluminum requires nearly 5% of energy needed for primary production, that results in greenhouse gases emissions of 0,5 tons of CO2e. Recycled aluminum’s main route is for production of casting alloys. With proper metallurgical processing scrape and aluminum waste can be used to make almost any product: wheels, chassis, transmissions in transport sector; facades, windows, doors in construction; cans, foil in packaging; solar panels, wind farms, aluminum-ion batteries in renewable energy and so on.
 For alloys made from secondary raw materials, beside the creation of a protective layer on the surface of the melt, which prevents its saturation with hydrogen and oxides during contact with the furnace atmosphere, it is important to ensure effective chemical destruction of oxides on the surface of microvolumes of aluminum melt and decrease the content of hydrogen and other dissolved gases. High efficiency in treatment of aluminum alloys made from scrape and waste has shown the modification, which is carried out to improve the structure (grinding grains, dendritic branches, structural components, dispersing particles of the secondary phases, giving them a favorable shape, etc.) and obtain the material with necessary mechanical and service properties.
 When choosing a composition for both flux refining and modification, it is necessary to take into account not only materials science aspects of the problem, but also the impact of their composition on the health and safety of production personnel, city residents and the environment.