Ensuring the sustainable supply of semiconductor material: A case of germanium in China

The semiconductor industry relies on the sustainable supply of critical mineral resources, such as Germanium (Ge), a key metal used in making electronics, fiber cables and solar cells. However, since Ge is a companion element, its primary production is constrained by the availability of host minerals such as zinc and coal. As such, its recycling is challenging since both recycling networks and technologies are still in its early infancy. There are increasing concerns on how to meet with the future demand for Ge due to its limited supply. This study aims to uncover the metabolic characteristics of the Ge cycle in China for the period of 2002–2021 from a whole life cycle perspective by employing a dynamic material flow analysis. The results show that China's demand for Ge had increased from 19.16 tons in 2002 to 85.87 tons in 2021. Fiber cables and infrared optical instruments consumed the most Ge resource, accounting for 54.59% and 36.76% of the total Ge consumption, respectively. The in-use Ge stock had increased more than 40 folds, implying a substantial potential for future recycling. The majority of Ge was extracted from coal ash and zinc concentrates, with figures of 1086.92 tons and 585.27 tons respectively, while only 13.45 tons of Ge were recovered from those end-of-life products. Furthermore, the Ge loss reached 1586.31 tons at the production stage. The Ge stock in those intermediate products has gradually decreased. The cumulative Ge export amount contained in various products was 655.64 tons, mainly dominated by intermediate products, while the share of final products increased in recent years. Based on these findings, several policy recommendations are proposed, including improving Ge production efficiency and expanding Ge supply sources, establishing a comprehensive Ge recycling system, and upgrading the entire Ge industrial chain. These policies can help better cope with the challenges that the global semiconductor supply chain is facing.