Life Cycle Sustainability Assessment of rare earth permanent magnets

Permanent magnets are used in many modern technologies due to their high density of electromagnetic energy. Typically neodymium, praseodymium and dysprosium, three rare earth metals, determine these technical properties. Whereas the demand for rare earth increases constantly, controversial debates emerge in parallel concerning environmental impacts during rare earth production, pressure on market prices due to almost monopolistic production in China, failed attempts to set up western production routes or missing acceptance from local communities at production sites. Therefore, rare earth metals provide an ideal subject for a Life Cycle Sustainability Assessment (LCSA) considering environmental, economic and social aspects.Given the current situation in rare earth production, this study compares three major supply chains from three different rare earth element (REE) deposits: (1) China represents the largest REEs producer worldwide (85%) with its biggest mine in Bayan Obo; (2) Australia is the second largest producer worldwide (8%) and the largest one in the Western World. While mining and beneficiation take place in Australia (Mount Weld mine) the separation is carried out in Malaysia; (3) The Mountain Pass mine in the United States, as a former third largest producer worldwide (3%), is assessed also. Today, the subsequent production of a typical neodymium iron boron magnet (NdFeB) is conducted in China only. Setting up this case study contributes to further develop LCSA methodology more generally, while at the same time giving inside into sustainability aspects of rare earth production in more detail. However, data availability especially for China is one of the biggest problems. For each rare earth supply system a basic process chain is set up and then analysed for the three dimensions, ecology, economy and social aspects using different levels of aggregation. Based on these results different approaches to normalize, weight and aggregate the different indicators of the three dimensions are applied.The results indicate that the supply chain with REE from the USA has the lowest social and environmental impacts as well as low cost. The supply chain from the Chinese REE deposit shows very low costs as well. However, the environmental and social impacts are much higher for this option than for the other two. Only when economic reasons are weighted more important than environmental and social effects China can catch up with the western countries