Waste as a Source of Critical Raw Materials—A New Approach in the Context of Energy Transition

Critical raw materials are economically and strategically important for industry both in the short and long term. However, their supply is at high risk due to limited domestic deposits and reliance on imports. As demand for these materials grows, alternative sources must be explored. This study investigates the recovery of critical raw materials from waste, focusing on incineration residues, industrial byproducts, and electronic waste. The research analyzes various waste streams, including municipal solid waste incineration bottom ash and fly ash, as well as electronic and industrial waste, to determine their potential as secondary sources of critical materials. Key elements targeted for recovery include rare earth elements (REEs), antimony, vanadium, cobalt, and other strategic metals. The study evaluates the effectiveness of hydrometallurgical, pyrometallurgical, bioleaching, and electrochemical techniques for their extraction. Findings indicate that bottom ash contains 1–3% ferrous metals and up to 0.4% non-ferrous metals, including rare earth elements, while fly ash has substantial quantities of heavy metals suitable for recovery. The study highlights that large-scale recovery of critical raw materials from waste could reduce reliance on primary sources, support the circular economy, and enhance supply chain resilience in the context of energy transition. By providing a comprehensive assessment of recovery technologies and their economic and environmental implications, this study underscores the importance of waste as a valuable resource for critical material supply. The findings contribute to policy discussions on sustainable resource management and the reduction of geopolitical risks associated with raw material dependency.