Towards Greener Coal Mining: A Life Cycle Assessment Model for Small-Scale Underground Operations

Despite global initiatives towards green energy, coal remains a vital energy source, and the environmental repercussions of its extraction, especially in small-scale operations, are not thoroughly understood. The objective of this study is to address the pressing environmental impacts associated with small-scale coal mining in the context of developing countries, exemplified by Pakistan. The life cycle assessment (LCA) method, leveraging SimaPro 9.0 software, was used to evaluate the ecological footprints of small-scale coal mines. Background data were sourced from the Ecoinvent v3 database, and midpoint results with uncertainty information were calculated using the ReCiPe 2016 Midpoint (H) method. The developed life cycle inventory is applied for the first time in a case study, and all the processes are investigated based on the functional unit of 1 tonne of coal production. Normalization results reveal that marine ecotoxicity poses the highest environmental pollution risk, followed by human carcinogenic toxicity, freshwater ecotoxicity, human non-carcinogenic toxicity, terrestrial ecotoxicity, and fossil resource scarcity. Contribution analysis indicates that underground coal mine, ventilation system, and hoisting system significantly contribute to these impact categories and require special attention. According to the sensitivity analysis, the main countermeasures for addressing environmental issues are to reduce coal mining activities and improve the efficiency of coal mining and utilization for green coal production. Finally, the environmental hotspots specific to small-scale coal mining operations were identified, and technical measures were proposed. This study serves as a baseline for small-scale coal mines, offering valuable insights and methodologies that can be applied to similar mining operations worldwide.