Criticality of metals and metalloids.

Title	Criticality of metals and metalloids.
Authors	T E Graedel, E M Harper, N T Nassar, Philip Nuss, Barbara K Reck
Magazine	Proceedings of the National Academy of Sciences of the United Kingdom
Date	04/07/2015
DOI	10.1073/pnas.1500415112
Introduction	The balance between metal supply and demand, whether actual or anticipated, has led to the concept of metal criticality. This study evaluates the criticality of 62 metals and metalloids within a three-dimensional framework: supply risk, environmental impact, and susceptibility to supply restrictions. Factors contributing to extreme criticality include geopolitical concentration in production, lack of substitutes, and political instability. Emerging electronics face supply risks, particularly for metals such as gallium and selenium. Environmental concerns dominate for precious metals including platinum, gold, and mercury. Steel alloying elements, such as chromium and niobium, and high-temperature alloys, like tungsten and molybdenum, are vulnerable to supply restrictions. Metals of greatest concern are often by-products, used in small quantities for specialised applications, and have no effective substitutes.
Quote	T E Graedel, E M Harper and N T Nassar et al. Criticality of metals and metalloids. Proceedings of the National Academy of Sciences of the United Kingdom of Great Britain and Northern Ireland. 2015. Vol. 112(14). DOI: 10.1073/pnas.1500415112
Element	Gallium (Ga) , Selenium (Se) , Platinum (Pt) , Mercury (Hg) , Chromium (Cr) , Niobium (Nb) , Tungsten (W) , Molybdenum (Mo)
Materials	Precious Metals
Topics	Environmental and Green Materials
Industry	Electronics