The anthropogenic cycle of zinc: Status quo and perspectives

- We present comprehensive zinc cycles at global, regional, and country levels.
- The global zinc end-of-life recycling rate is 33%; the recycled content is 27%.
- A novel approach is used to estimate the global zinc in-use stock at 170 Tg.
- Collecting more old scrap from buildings and vehicles could help close zinc cycles.
- Foreseeable technological change should not significantly affect zinc cycles.

Zinc is a key metal of industrial society that saw an unprecedented growth of its use between 2000 and 2010, largely driven by demand in China. Nonetheless, a contemporary understanding of multi-level stocks and flows of zinc is lacking. This paper presents the cycles of relevant countries, eight world regions, and the globe for 2010, relying on material flow analysis (MFA) for results that have the potential to inform policy makers and future research. We estimate the global zinc end-of-life recycling rate at 33%, which helps achieve a 27% of fabricated zinc coming from secondary sources. Most losses occur in waste management, most of it in the end use sectors construction and transportation. Increasing collection rates in these two sectors should be a priority for closing the zinc cycle. China dominates the global anthropogenic zinc cycle, and relies on primary zinc from Latin America and the Caribbean and Oceania to support its zinc demand. Government and industry in Europe and North America should anticipate shifts in exports of their zinc-containing scrap due to the growing availability of Chinese end-of-life zinc. Further research combining this study with scenario analysis could provide the knowledge base to answer questions related to this issue.

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