Simultaneously tracing the fate of seven metals at a global level with MaTrace‐multi
Christoph Helbig, Yasushi Kondo, Shinichiro Nakamura
Abstract
Keeping materials in use for a long time is key to reducing primary material demand and environmental impacts of resource use. Recycling yields of metals should only be limited by thermodynamically unavoidable losses of the remelting processes for well-defined scraps. In practice, however, additional dissipative losses for metals occur due to incomplete collection of end-of-life products, insufficient waste sorting, remelting of contaminated or diluted scrap, and the downcycling of secondary materials. Here we simultaneously trace the fate of Al, Cr, Fe, Ni, Cu, Zn, and Pb in MaTrace-multi, a planetary dynamic material flow system. Metals pass the processes mining, fabrication, use-phase, collection, sorting, scrap allocation, remelting, and secondary material allocation. We calculate the circularity and longevity of the cohort of metal requirements for the final demand of 1 year. Nickel is found to have the best longevity at 116 (78 to 205) years, whereas zinc only has a longevity of 47 (37 to 61) years. While nickel, on average, is used in 5.13 (3.45 to 8.78) applications before dissipation, zinc is used only in 1.94 (1.52 to 2.47) applications. Our study results can be used to model the impacts of circular economy policies and technological developments on global metal cycles beyond the scope of studies modeling one metal at a time. This article met the requirements for a Gold–Gold JIE data openness badge described at http://jie.click/badges