Material Flow Analysis of Dysprosium in the United States.

Dysprosium (Dy) is increasingly being adopted in various clean energy products around the world, intriguing many nations' interests in its availability. However, since data are inaccessible, crucial information about Dy supplies and demands across products and countries remains incomplete. To fill these knowledge gaps, we performed a dynamic bottom-up material flow analysis of Dy, taking the United States (1987-2018) as a case. The results show that the United States (US) domestic demands experienced a growing trend (by 45-fold) with fluctuation and several shifts among applications, primarily owing to technological advancement. A large imbalance (80 times) exists between domestic mineral supplies and market demands, resulting in significant import dependency, with the net import reliance of alloys, chemicals, finished products, and concentrates being 97, 44, 40, and 31%, respectively. Dy is mainly imported as finished products (55.7%) and alloys (43.2%), with concentrates (0.4%) and chemicals (0.7%) accounting for less than 2%. This import dependency may result from fragmentation of the US supply chains because of the stricter environmental regulations on upstream industries and reshoring of the downstream industries. These findings suggest that rare-earth mineral production in the US is about to restart, and it is important for industries to seek international collaboration to boost product competition.

China economy-wide material flow account database from 1990 to 2020.

Material utilisation has been playing a fundamental role in economic development, but meanwhile, it may have environmental and social consequences. Given China's rapid economic growth, understanding China's material utilisation patterns would inform decisions for researchers and policymakers. However, fragmented data from multiple statistical sources hinder us from comprehensively portraying China's material utilisation dynamics. This study harmonised China-specific official statistics and constructed a China economy-wide material flow accounts database. This database covers hundreds of materials and more than 30 years (1990-2020) from thousands of data sources, which is comprehensive, long-term, up-to-date, and publicly accessed. This database would provide insights into the historical metabolic dynamics of China's economy with elaboration on the production, consumption, and end-of-life disposal of materials. This database also allows for international analyses since it is developed based on an internationally standardised analytical framework. Furthermore, this study would benefit studies on policy impact evaluation, environmental pressure assessment, and sustainable development strategies.