Kadivar Saeede, Akbari Hamid, Vahidi Ehsan
Mackay School of Earth Sciences and Engineering, Department of Mining and Metallurgical Engineering, University of Nevada, Reno, NV, USA.
Kinross Gold Corporation, Las Vegas, NV, USA.
Sci Total Environ. 2023 Dec 20;905:167841. doi: 10.1016/j.scitotenv.2023.167841. Epub 2023 Oct 16.
Despite the strict environmental management regulations, there is still a considerable adverse impact on the ecosystem and human health when it comes to large-scale gold mining operations. Gold mining is an energy-intensive process that can discharge substantial quantities of chemicals combined with gaseous emissions into the environment. Considering gold mining's significant role in Nevada's economy and the growing concern about climate change, it's necessary to investigate the environmental burdens of this sector. To provide a comprehensive environmental perspective on the large-scale gold mining operations in Nevada, this study used a life cycle assessment (LCA) approach to evaluate the environmental burdens of gold production from double refractory ores in the roasting process. The Tool for Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) method was used to evaluate the categories of acidification, ozone depletion, global warming, smog, carcinogenics, non-carcinogenics, respiratory effects, and fossil fuel depletion. Results showed that major contributors to greenhouse gas (GHG) emissions were grinding and off-gas treatment stages being responsible for 34.80 % and 56.10 % of the total global warming, respectively. The carbon footprint for producing one kg of gold was 12,200 kg CO-eq. Sensitivity analysis was also employed on electricity to observe the influence of electricity on key contributor stages. A 10 % change in electricity reduced the GHG emissions in crushing and grinding by 12.2 % and 7.10 %, respectively, while delivering an insignificant effect on the off-gas treatment. Significantly, this study stands as the first initiative to apply LCA in the North American mining industry, with a unique focus on the off-gas treatment post-roasting and its associated emissions. Our findings can serve as a foundational database, aiding stakeholders in making informed decisions and enhancing sustainable practices in the gold mining industry.
尽管有严格的环境管理规定，但大规模金矿开采作业仍对生态系统和人类健康造成相当大的不利影响。金矿开采是一个能源密集型过程，会向环境中排放大量化学物质和气态污染物。鉴于金矿开采在内华达州经济中发挥的重要作用以及对气候变化的日益关注，有必要调查该行业的环境负担。为了全面了解内华达州大规模金矿开采作业的环境状况，本研究采用生命周期评估（LCA）方法来评估焙烧过程中双重难处理矿石黄金生产的环境负担。使用化学及其他环境影响减少与评估工具（TRACI）方法来评估酸化、臭氧消耗、全球变暖、烟雾、致癌物质、非致癌物质、呼吸影响和化石燃料消耗等类别。结果表明，温室气体（GHG）排放的主要贡献阶段是研磨和废气处理阶段，分别占全球变暖总量的34.80%和56.10%。生产1千克黄金的碳足迹为12,200千克二氧化碳当量。还对电力进行了敏感性分析，以观察电力对关键贡献阶段的影响。电力变化10%分别使破碎和研磨过程中的温室气体排放量减少了12.2%和7.10%，而对废气处理的影响不显著。值得注意的是，本研究是北美采矿业首次应用生命周期评估的举措，特别关注焙烧后的废气处理及其相关排放。我们的研究结果可作为一个基础数据库，帮助利益相关者做出明智决策，并加强金矿开采行业的可持续做法。
