The issues around materials criticality can be quite complex, and vary considerably from metal to metal. Most metals do not suffer from an absolute scarcity in the Earth’s crust, though they may be dispersed in a way that makes them costly to extract. More frequently they are unavailable to the market due to their limited supply from a small number of high grade sources, combined with policies developed around resource nationalism or export taxes and quotas. In addition responses to mitigate metals security (e.g. recycling, reuse, substitution) require a good understanding of the supply chain, technology evaluation and the science behind their applications.

Metals recovery is put forward as a key approach for alleviating material security concerns (along with substitution). Recovery rates are often hampered by a lack of collection and separation of the products, particularly for speciality metals where the degree of dispersion can be high. For many metals recycling technologies do exist to at least demonstration level, but implementation for large scale recycling will require significant investment. This has the potential to complement primary extraction, although not replace it due to the forecast demand growth rates and longevity of products.