Linking regional MFA models: Understanding disparities within the global zinc cycle

Abstract

Circular economy and criticality assessments require comprehensive monitoring of anthropogenic material flows and stocks at a regional level. Therefore, this study presents a multiregional trade-linked dynamic MFA model for zinc. The model covers the entire life cycle from mining to recycling for the regions China, Europe, North America, Latin America, and Asia. The dynamic approach allows the analysis of the development of the cycles from 1995 to 2020. The interregional trade is quantified at each life cycle stage by using the Comtrade database. Sensitivity analysis is applied to account for uncertainties in the exogenous data. The results reveal large regional disparities in the zinc industry. While China shows enormous growth, Europe has already reached a steady state in zinc consumption and anthropogenic stock. The current global consumption is strongly driven by China, leading to a strong increase of its zinc stock in use. However, Europe has the largest zinc stock in use, especially on a per capita basis. North America's zinc consumption is decoupled from its economic growth, as evidenced by the recent decline in its zinc stock in use. In terms of recycling, Europe shows the highest volumes and the best circular performance, as indicated by high recycling rates, partly due to the extensive use of more easily recyclable product types. In all regions, there is potential for increased recycling by treatment of zinc-bearing steelmaking dusts. China's strict regulation successfully triggered large-scale implementation of respective recovery processes, leading to increasing recycling rates. This article met the requirements for a gold-gold JIE data openness badge described at http://jie.click/badges.