Dynamic accounting and spatiotemporal emission characteristics of carbon emissions in the entire production process of open-pit coal mine

A carbon emission accounting framework covering the entire coal production process is a prerequisite for identifying carbon source characteristics, optimizing low-carbon pathways, and reducing energy consumption intensity, and it also forms the basis for the low-carbon transition of coal enterprises. Taking a typical open-pit coal mine in northern China as a case study, the production process is divided into eight major stages — such as ore/coal mining, hauling, and dumping — according to the characteristics of open-pit mining, and direct and indirect emission sources at each stage are systematically identified. Based on a life-cycle perspective, a dynamic monthly carbon emission accounting model is developed using the emission factor method, enabling monthly carbon emission accounting across the entire production chain. The results indicate that: Carbon emissions from mining area production activities exhibit a “fugitive-dominated and process-concentrated” pattern. Diesel-driven outsourced stripping, hauling and dumping constitute high-emission stages, whereas electricity-driven loading and coal washing demonstrate clear carbon emission advantages. Optimization of the energy structure leads to a reduction in carbon emission intensity, with decrease in diesel consumption contributing more than electricity substitution. Monthly carbon emissions are positively correlated with raw coal output (r=0.99, P≤0.001) and increase noticeably with capacity expansion. Meanwhile, carbon emission intensity continues to decline, with its fluctuation range narrowing to 48.95−54.98 kgCO₂e/t raw coal, indicating that capacity expansion and energy efficiency improvement can be promoted synergistically. Emission reduction potential is mainly concentrated on improving the operational efficiency of outsourced activities, electrifying mobile equipment in high diesel-consumption stages such as hauling, dumping, enhancing ecological restoration quality, and forward-looking deployment of CO₂ capture, utilization, and storage (CCUS) technologies. The carbon emission accounting framework developed herein not only provides a quantitative approach for refined carbon footprint management in open-pit coal mines, but also offers scientific support for formulating targeted emission reduction policies in similar mines, contributing to the coal industry’s achievement of “dual carbon” goals and holding significant practical value.