Environmental impacts and carbon footprint of high-value recycling of NdFeB scrap under life cycle assessment

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.