Climate Impact of China’s Promotion of the Filling Mining Method: Bottom-Up Estimation of Greenhouse Gas Emissions in Underground Metal Mines

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.

Developing climate neutrality among supply chain members in metal and mining industry: natural resource-based view perspective

“…Excavation operations, which lie on the sourcing side of the M&M supply chain, cause GHG emissions, such as CO 2 (Gorman and Dzombak, 2018;Gupta and Basu, 2019;Liu et al, 2021) and methane (Kholod et al, 2020), as well as deforestation, which leads to a reduced carbon sink (Liu et al, 2021). Processes like weathering, neutralization of waste rock and tailings, acid leaching, and metallurgical processing can also lead to GHG emissions, due to the decomposition of carbonate minerals, such as siderite (FeCO 3 ) and calcite (CaCO 3 ).…”

“…Excavation operations, which lie on the sourcing side of the M&M supply chain, cause GHG emissions, such as CO 2 (Gorman and Dzombak, 2018; Gupta and Basu, 2019; Liu et al. , 2021) and methane (Kholod et al.…”

“…, 2021) and methane (Kholod et al. , 2020), as well as deforestation, which leads to a reduced carbon sink (Liu et al. , 2021).…”

An Integrated Gray DEMATEL and ANP Method for Evaluating the Green Mining Performance of Underground Gold Mines

“…China, as a major mining country, faces an even tougher situation [2]. To solve the environmental problems and achieve sustainable development, China has proposed a green mining (GM) policy [2][3][4], with financial and tax incentives. Furthermore, many mines have joined the ranks of GM construction.…”

Destruction Characteristics and Control Countermeasure of Shaft Surrounding Rock Mass in Complex Geological Environment

“…With the improvement of deep mineral resource exploration technology, there are more deep vertical shafts being constructed in China's underground mines [15]. The number of shafts with a depth of more than 1000 m exceeds 30, and most of them are within 1200 m [16,17]. For example, the main shaft of Angang Gongchangling Iron Mine has a depth of 1022 m, the depth of the new auxiliary shaft of the Chengchao Iron Mine of Wuhan Iron and Steel Co., Ltd. is 1135 m, the main shaft of Tongling Nonferrous Dongguashan Copper Mine is 1125 m, the depth of the mixing shaft in the Dongfeng mine field of Linglong Gold Mine is 1018 m, and the depth of the mixed shaft of Jinchuan Longshou Mine is 1083 m [18][19][20].…”