Resource utilization of coal gangue through geopolymerization: Unraveling trends, gaps, and circular economy insights

Abstract

Coal gangue (CG) is among the world’s most plentiful industrial solid wastes, and its accumulation in spoil heaps poses numerous environmental hazards – ranging from self-ignition and slope instability to land occupation and the leaching and weathering of pollutants that degrade air, soil and water. Geopolymerization offers a viable means of transforming this mining by-product into low-carbon construction materials. This work presents the first systematic bibliometric survey and literature review of CG-based geopolymers, analyzing publications from their inception in 2008 until recent studies. Using the Scopus database and VOSviewer for visualization, the study tracks the field’s evolution, highlights landmark papers, key journals and highly cited articles, and quantifies the contributions of leading researchers, institutions and countries while revealing patterns of international collaboration. Keyword co-occurrence clustering further delineates dominant research themes, emerging priorities and current trajectories, providing a comprehensive snapshot of the global knowledge landscape. Finally, the analysis identifies persistent challenges and knowledge gaps and points to promising directions for future inquiry, providing actionable guidance for both academia and industry.