Assessing the supply potential of high-tech metals - A general method

The demand for some of the rarer elements in the Earth's crust, mostly from high-tech applications, is increasing rapidly. Many of these elements are produced exclusively as by-products resulting in potentially significant supply limitations. In this article, a general method for the assessment of the supply potential of such elements is developed from a conceptual model of the supply-chain. Namely, statistical and deterministic models are introduced to quantify both the variability in by-product concentrations in the relevant raw materials, as well as the effects of this variability on achievable recoveries. The assessment of uncertainties is implemented via Monte-Carlo-type simulations. Presentation of the results in availability curves ensures adaptability to future changes in market conditions, while extensive documentation of the assessment method, available as electronic supplementary material with this article, ensures reproducibility.
A simple example is used to illustrate the complete estimation process. It shows that in addition to ensuring future adaptability of the results, availability curves are also useful for the assessment of the current supply regime of a given by-product. An elastic and inelastic regime might be distinguished – in the elastic regime, significant demand-driven increases in by-product supply are possible without increases in the production of the main product, while in the inelastic regime this is not the case. The method presented in this article is the first to enable such an assessment to be made in a reliable and transparent manner.