Soil reconstruction technology for ecological restoration of mines: from utilization of solid waste to ecological recovery

The development of mineral resources leads to ecological degradation problems such as soil compaction, loss of organic matter, and heavy metal pollution. Soil reconstruction in mining areas is central to mine ecological restoration, with the core goal of restoring the productivity and ecological functions of damaged soil through physical, chemical, and biological means. In recent years, the resource utilization of mining solid waste has provided new material sources and technical paths for soil reconstruction. The integration of the multi-index decision-making model, field experiments, and numerical simulation has optimized the proportion of solid waste-based materials and reduced technical costs. Consequently, mining solid wastes such as coal gangue, fly ash, and steel slag can effectively improve soil physical structure, water regulation, and heavy metal immobilization through improvement and precise proportioning. The layered reconstruction makes the porosity reach or approach natural levels. Technologies such as vegetation bags and soil-like spray seeding have overcome the problem of restoring steep slopes of 60° to 90°. Moreover, mixed vegetation combined with microbial regulation significantly enhances carbon sequestration capacity. The four-dimensional index system supports quantitative evaluation; however, long-term risks associated with solid waste and regional adaptability continue to pose significant challenges. Future efforts should focus on developing intelligent early warning platforms and standards for different types of mines to promote the construction of "waste-free mines" and achieve the sustainable recovery of the mining area ecosystem.