Wang Tong, Berrill Peter, Zimmerman Julie B, Hertwich Edgar G
Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States.
Center for Industrial Ecology, Yale University, New Haven, Connecticut 06520, United States.
Environ Sci Technol. 2021 Apr 20;55(8):5485-5495. doi: 10.1021/acs.est.0c08227. Epub 2021 Mar 30.
Is recycling a means for meeting the increasing copper demand in the face of declining ore grades? To date, research to address this question has generally focused on the quantity, not the quality of copper scrap. Here, the waste input-output impact assessment (WIO-IA) model integrates information on United States (US) economy-wide material flow, various recycling indicators, and the impact of material production from diverse sources to represent the quantity and quality of copper flows throughout the lifecycle. This approach enables assessment of recycling performance against environmental impact indicators. If all potentially recyclable copper scrap was recycled, energy consumption associated with copper production would decrease by 15% with alloy scrap as the largest contributor. Further energy benefits from increased recycling are limited by the lower quality of the scrap yet to be recycled. Improving the yield ratio of final products and the grade of diverse consumer product scrap could help increase copper circularity and decrease energy consumption. Policy makers should address the importance of a portfolio of material efficiency strategies like improved utilization of copper products and lifetime extension in addition to encouraging the demand for recycled copper.
面对矿石品位下降，回收利用是否是满足不断增长的铜需求的一种手段？迄今为止，针对这个问题的研究通常集中在废铜的数量上，而非质量。在此，废物投入产出影响评估（WIO-IA）模型整合了美国全经济范围物质流、各种回收指标以及不同来源物质生产影响等信息，以呈现整个生命周期内铜流的数量和质量。这种方法能够根据环境影响指标评估回收性能。如果所有潜在可回收的废铜都得到回收利用，那么与铜生产相关的能源消耗将减少15%，其中合金废料的贡献最大。然而，因待回收废料质量较低，进一步增加回收带来的能源效益受到限制。提高最终产品的产出率以及不同消费产品废料的品位，有助于提高铜的循环利用率并降低能源消耗。政策制定者除了鼓励对再生铜的需求外，还应重视一系列材料效率策略的重要性，如提高铜产品的利用率和延长使用寿命。
