| Abstract |
Coal gangue, a byproduct of coal mining and processing, has long been regarded as solid waste. However, with the increasing severity of resource scarcity and environmental pollution issues, the efficient utilization and resource recovery of coal gangue have become urgent needs. This paper reviews the modification and resource utilization of coal gangue, focusing on its introduction, pretreatment, modification methods, and the latest progress in resource utilization. Firstly, coal gangue is a porous granular material composed mainly of inorganic minerals, organic matter, and water. Due to its complex nature and diverse composition, the direct utilization of coal gangue is somewhat limited. Therefore, modifying coal gangue is a key step in achieving its resource utilization. Pretreatment before modification is a crucial step to ensure the effectiveness of coal gangue modification. This involves physical processes such as crushing, screening, magnetic separation, and washing of coal gangue to reduce particle size, achieve uniformity, enhance surface area and pore structure, thereby providing a solid foundation for subsequent modification. The modification methods of coal gangue mainly include chemical modification, biological modification, and composite modification. Chemical modification involves introducing functional groups or altering its chemical structure through processes such as acid-base treatment, organic modification, thermal activation, etc., thereby improving its adsorption performance, dispersibility, etc. Biological modification utilizes microorganisms, enzymes, and other biological systems to enhance the environmental friendliness and biocompatibility of coal gangue. Composite modification combines the advantages of various modifications to make coal gangue-based materials meet requirements better. Significant progress has been made in the resource utilization of coal gangue. Modified coal gangue is extensively utilized in environmental management sectors like soil remediation and wastewater treatment, showcasing excellent adsorption capabilities and catalytic activity. Furthermore, modified coal gangue is utilized as raw material in sectors such as construction materials, energy recovery, and fertilizer production, providing a new pathway for reducing mineral resource consumption and advancing circular economy development. |