Multistage Recycling of Aluminum Casting Slags: Metal Extraction and Salt Flux Regeneration

The depletion of natural resources remains an acute global problem, highlighting the importance of developing sustainable technologies that enable the simultaneous extraction of metals and recycling of waste. This paper describes a study of a technology for recycling aluminum slag from foundries to produce secondary aluminum alloy and regenerated flux. Research and processing methods include X-ray phase and spectral analysis of slag composition, multi-stage grinding in a jaw crusher and planetary mill, screening for fraction separation, and selective dissolution of the oxide–salt phase in water or hydrochloric acid followed by filtration and evaporation; obtaining regenerated flux based on phase diagrams of chloride systems; and briquetting and remelting of the extracted aluminum. The technology ensures the extraction of up to 85% of the metallic aluminum from slag and the production of regenerated flux based on the NaCl–KCl–MgCl2 system with a low melting point.