Abstract
China recently implemented a “Green Mine” policy focused on promoting the filling method, aiming to mitigate the environmental impacts of underground mining; nevertheless, quantitative inventories have rarely been provided to support or negate such promotion, especially from a life-cycle perspective. Accordingly, this paper proposes a bottom-up model for estimating life-cycle greenhouse gas (GHG) emissions from underground metal mines using either filling or caving methods. Two filling-based (Luohe and Longtangyan) and two caving-based (Maogong and Xiaowanggou) iron mines were studied; their direct GHG emissions were 0.576, 0.278, 2.130, and 1.425 tons of carbon dioxide equivalent per kiloton-extracted ore (t CO2 eq/kt), respectively. When indirect GHG emissions were considered, the results increased to 17.386, 15.211, 5.554, and 5.602 t CO2 eq/kt, respectively. In contrast to popular belief, such results demonstrate that promoting the filling method can potentially raise the overall GHG emissions. Although filling-based projects generate less direct GHG emissions, the emissions are transferred to upstream sectors, especially the cement and power sectors. The additional electricity consumption in the haulage and backfilling stages is primarily responsible for the greater GHG emissions occurring in filling-based projects. Some mitigation approaches are suggested, such as backfilling the subsidence pit, using industrial waste as cementing materials, employing energy-efficient pumps, and further developing hauling systems.
Highlights
China has been the largest greenhouse gas (GHG) emitter for more than 15 years [1].To mitigate global climate change, China has implemented numerous policies to conserve energy and reduce GHG emissions in different industrial sectors [2,3,4]
The results from the case studies of Luohe, Longtangyan, Maogong, and Xiaowanggou show that filling-based projects generate less direct GHG emissions than those based on caving, indicating that the aforementioned promotion helps to mitigate GHG emissions that occur directly in the mining sector
The filling method is regarded as a cleaner approach for underground metal mines, and has been promoted in China
Summary
To mitigate global climate change, China has implemented numerous policies to conserve energy and reduce GHG emissions in different industrial sectors [2,3,4]. “Green Mine” is a mandatory policy recently released by China’s Ministry of Natural Resources (MNR), which aims to mitigate the environmental impact of the mining sector. In this policy, the filling method, rather than open-stope or caving methods, is promoted in China’s underground mines [5]. The land occupation for storing waste rocks and tailings further deteriorates such destruction Such drawbacks restrict the application of caving methods in China [9,10]. To test the impacts of China’s promotion policy regarding the filling method on the climate, four underground iron mines (two using the caving method and two using the filling method) are studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
