Recycling of Waste Refractories from Failure Mechanisms to High-Value Regeneration Pathways: A Systematic Review

The high-speed growth of high-temperature industries has resulted in an increase in the generation of waste refractories (WRs) whose resource consumption is a significant concern towards low-carbon targets and the circular economy. This review thoroughly analyzes the mechanisms of physical failure, such as thermal shock and mechanical stress, and chemical failure, including oxidation, erosion, and permeation. Such processes cause compositional complexity and structural degradation, which are the main barriers to recycling. The review discusses the classification-based recycling approaches, including closed-loop recycling, which reprocesses waste into shaped or unshaped refractories through particle-size optimization and binder modification, and open-loop recycling, which converts waste into metallurgical or chemical feedstocks, construction materials, and functional ceramics or thermal storage media. Combining failure mechanisms with regeneration pathways, this review proposes innovative strategies for high-value recycling, offering systematic direction to the green transformation and sustainable use of resources in high-temperature industries.