Abstract
Currently, the recycling of ash-slag waste generated by thermal power plants and the efficient recovery of valuable metals such as aluminum from these materials represent one of the most important environmental and economic challenges. Traditional aluminum extraction methods, including acid and alkaline leaching, high-temperature thermal treatment, pyrometallurgical processes, and organic extraction techniques, are characterized by high energy consumption, significant environmental impact, and low economic efficiency. This review provides a comprehensive analysis of modern methods for extracting aluminum from industrial ash-slag waste, comparing their efficiency, energy consumption, and technological limitations. Special attention is given to microwave-assisted leaching technology using amorphous graphite, and its advantages over conventional methods are systematically evaluated. The results of the literature review indicate that microwave-assisted leaching is a promising approach due to its energy efficiency, accelerated reaction kinetics, increased aluminum dissolution rate, and reduced environmental burden. Furthermore, this review highlights the scientific advantages of the proposed technology and identifies key areas for further development, including optimization of microwave penetration depth, power input, and temperature regimes. Thus, this review systematizes the scientific basis for the application of microwave technologies in the processing of ash–slag waste and contributes to the development of new, environmentally friendly methods for the efficient recovery of aluminum from waste materials.