Behind of the criticality for rare earth elements: Surplus of China's yttrium

Yttrium (Y), mainly using for phosphors, is considered as one of critical rare earth elements (REEs) in several countries. However, its flows and stocks in the whole life and fundamental supply and demand are still unclear, leading to that it is difficult to measure its criticality. This study aims to estimate China's Y flows and stocks for the period of 2000-2019 by applying dynamic material flow analysis. The results indicate that: (1) 146 kilo tons (kt) Y concentrates were flowed into anthropogenic system, and 33 kt Y were used in fluorescent lights, accounting for 80% of the total final use; (2) Y supply had been imbalanced with its demand, generating 39 kt Y surplus during the study period; (3) accumulative net Y export was 55 kt, in which primary products and final products accounted for 84% of the total export. Finally, three policy implications are proposed, including dynamic and specific list of individual critical REE, emergent Y recycling plans, and comprehensive stockpile policies.

Automated summary

This study analyzed the flows and stocks of yttrium (Y) in China from 2000 to 2019, revealing an imbalance between supply and demand with a surplus of 39 kt of Y generated during the period. The cumulative net Y export was 55 kt, with primary products and final products accounting for 84% of the total export. Additionally, three policy implications were proposed, including a dynamic and specific list of individual critical rare earth elements, emergent Y recycling plans, and comprehensive stockpile policies.