Mapping the upstream journey of China's indium: A trade-linked substance flow analysis

As a metal raw material for developing emerging industries, many countries have increased the competition and storage of indium. As the country with the largest reserves and supply of indium resources, China's indium supply affects the development of global emerging industries. The current study of indium upstream of the chain is not comprehensive enough, ignoring some objects and the interaction between China and the rest of the world (RoW) in trade. This study establishes a trade-linked substance flow analysis (SFA) framework to explore the sources, pathways, and destinations of China's indium in the upstream flow of the industrial chain. The results indicate that from 2000 to 2019, in addition to the 21,335 tons mined domestically, 3603 tons of indium were brought to China through concentrates import. Faced with the input of so many resources, nearly 20,000 tons of indium flowed into the landfill, and 2526 tons of refined indium flowed into the stock because of the low recovery rate and insufficient downstream consumption. The accumulation of refined indium, disruption of indium refineries and manufacturers, and the dependence of foreign markets on China's low-priced refined indium have resulted in half of the refined indium produced being exported to developed countries. The production bottleneck of high-purity indium makes manufacturers import high-purity indium from these developed countries at high prices. The trade of indium metal causes the loss of resources and capital in China. This study implies that strengthening cooperation between indium refineries and manufacturers, breaking technical barriers, and increasing recovery rates can promote the sustainable development of indium resources in China and the RoW from the perspective of trade links.