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In recognition of the challenges posed by metal scarcity, The European Commission has compiled a list of ‘critical raw materials’ (CRMs), to which ‘unhindered access’ is required for the essential running of society. This list is subject to regular review and update, and the most recent version features 27 different materials: antimony, beryllium, borates, cobalt, coking coal, fluorspar, gallium, germanium, indium, magnesium, graphite, niobium, phosphate rock, silicon, tungsten, platinum group metals, light rare earths and heavy rare earths, baryte, bismuth, hafnium, helium, rubber, phosphorus, scandium, tantalum and vanadium.
These materials are deemed essential for the functioning of key economic sectors, including consumer electronics, automotive, aerospace, and renewable energy technologies. Notably, this list is not solely focused on scarcity but also:
The CRMs include metals such as cobalt, gallium, indium, rare earth elements, and various alloys, all of which are indispensable for technologies like solar panels and wind turbines. The unique properties of these materials often make them irreplaceable, underscoring the urgent need to secure their supply.
The issue of metal scarcity is rooted in the interaction of supply and demand. The production of renewable energy technologies requires significant amounts of critical metals, which are often sourced from a limited number of countries. This concentration of supply poses a risk of market instability, leading to price volatility and potential shortages. As the renewable energy sector expands, competition for these metals with existing industries—such as consumer electronics and traditional energy production—could exacerbate these challenges.
Despite the term ‘rare’, several REE have abundances in the Earth’s crust that are similar to chromium, nickel, copper, zinc, molybdenum, tin, tungsten and lead, and even thulium and lutetium (which are the least common of the group) are almost 200 times more abundant than gold.
Nonetheless, in contrast to the more usual base metals and also precious metals, REE tends not to become concentrated in exploitable deposits (ores), with the result that the majority of their global supply originates from only a few sources, mainly China of W, Sb, Mo, Ge, Ga and In: most of the world’s Pt, Pd, Rh, Ru and V are produced in South Africa (which provides 89% of the world’s platinum group metals); while 60%of the global supply of Co is mined in the Democratic Republic of the Congo (DRC), with its further implication as a ‘conflict mineral’ (see section on ‘Conflict minerals’).
When a single nation has a monopoly on the supply of a particular material, questions naturally arise over how secure this might prove in the longer term, and those nations whose manufacturing/technology base and economy are underpinned by imports of critical elements begin to search elsewhere for alternative sources. In the case of REE, various companies and countries that depend on them are making assiduous efforts to gain control of mineral rights in South Africa, Greenland, and Australia, while China, though plentiful in REE, is securing access to other minerals across the world
One of the most promising strategies for addressing metal scarcity is improving recycling processes. Recycling can recover valuable materials from end-of-life products, reducing the need for new mining operations. However, recycling rates for certain metals remain low, and the efficiency of current recycling technologies varies.
For instance, while some metals like aluminum and steel are widely recycled, others, like indium and gallium, present more significant challenges due to their lower concentrations in electronic waste.
To maximize the potential of recycling, advancements in technology and processes are crucial. Developing more efficient methods for recovering rare metals from discarded products will be essential for ensuring a sustainable supply chain for the future.
Given the limitations of critical metals, researchers and engineers are exploring alternatives based on Earth-abundant materials. For instance, recent advancements in solar technology have focused on developing materials that require less reliance on scarce metals.
Innovations in photovoltaics using materials like copper, zinc, and tin show promise, as these elements are more widely available and have lower environmental impacts.
By investing in technologies based on Earth-abundant materials, we can mitigate the risks associated with metal scarcity while maintaining the efficiency and effectiveness of renewable energy systems.