中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 5 May 2025 |
（1. China Enfi Engineering Corporation, Beijing 100089, China;
2. Institute of Technology for Carbon Neutrality, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China;
3. National Engineering Research Center of Green Recycling for Strategic Metal Resources, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
4. Institute of Circular Economy, Beijing University of Technology, Beijing 100124, China;
5. China Association of Circular Economy, Beijing 100037, China;
6. China Southern Rare Earth Group Co., Ltd., Ganzhou 341000, China）
Abstract:The NdFeB scrap, as a representative solid waste of rare earths, possesses significant recyclable value. This study focused on NdFeB waste and investigated the environmental impacts of pyro- and hydro-metallurgical process (PH-M process) and its improved version, the pyro- and hydro-metallurgical improvement process (PH-Mi process). The results demonstrate that, although the PH-Mi process consumes higher amounts of energy, electricity, and chemicals compared to the PH-M process, it is more environmentally friendly and economically efficient (i.e., net profit increased by 34.12%). To quantify and compare the environmental performance of the two scenarios, life cycle assessment methodology was applied. It is concluded that the PH-Mi process is superior to the PH-M process for eutrophication potential (EP) and the total environmental impacts. In comparison with PH-Mi process, PH-M process exhibits a certain advantage in terms of carbon footprint due to increased consumption of electricity and chemicals after the technological upgrade.
Key words: NdFeB scrap; molten salt electrolysis waste; life cycle assessment; environmental impact; carbon footprint
