Comparative Analysis of Supply Risk-Mitigation Strategies for Critical Byproduct Minerals: A Case Study of Tellurium

Abstract

Materials criticality assessment is an analytical framework increasingly applied to identify materials of importance to stakeholders who face scarcity risks. Although criticality assessment studies highlight materials for the implicit purpose of informing future action, the aggregated nature of the studies’ results make them poorly suited for use as guidance in nuanced strategy development and implementation. As a first step in the selection of mitigation strategies, the present work proposes a modeling framework and accompanying set of metrics to directly compare strategies by measuring effectiveness of risk reduction as a function of features of projected supply-demand balance over time. The work focuses on byproduct materials whose criticality is particularly important to understand because their supplies are less responsive to market balancing forces, i.e. price feedbacks. Tellurium, a byproduct of copper refining, critical to solar photovoltaics, is chosen as a case study and three commonly discussed byproduct-relevant strategies are selected: dematerialization of end-use product, byproduct yield improvement, and end-of-life recycling rate improvement. Results suggest that dematerialization will be nearly twice as effective at reducing supply risk as the next best option, yield improvement. Finally, due to its infrequent current use and dependence on long product lifespans, recycling end-of-life products is expected to be the least effective option, despite offering potentially other benefits (e.g. cost savings, environmental impact reduction).