Nedal T. Nassar Simon M. Jowitt Abraham J. Padilla Laurence R. Bird Dalton M. McCaffrey 2023 <p><span>Niobium, often classified as critical, is typically embedded within steels essential for infrastructure and transportation. Most niobium-consuming countries are import-dependent on primary stage niobium, meaning traditional material flow analysis, which often excludes critical commodities embedded within products of large-scale industries, would miss important flows in the fabrication and manufacturing stages and underestimate niobium consumption. This study presents the first dynamic (2000–2020) niobium flow analysis for two niobium-consuming, net import-dependent countries: the United States (U.S.) and China. Results demonstrate that the U.S. is import-dependent throughout all stages of the niobium flow cycle including embedded and primary flows, whereas China is only import-dependent on primary niobium. Moreover, while most U.S. imports of niobium embedded within (semi-)finished goods are consumed domestically, most niobium-containing goods manufactured in China are exported, suggesting a supply disruption would affect their economies differently. This research demonstrates the necessity of embedded flows for criticality assessments and evaluating supply restrictions.</span></p> application/pdf 10.1016/j.resconrec.2022.106698 en Elsevier Embedded critical material flow: The case of niobium, the United States, and China article