Cerium is the most abundant rare earth element, with technical applications in many industries. It is considered a critical mineral in the US and the EU.
Cerium is the most abundant of the rare earth elements (REEs). It has many industrial applications, including for chemical catalysis in the automotive industry, as an alloying element for high-performance steels, aluminium and other metals, and as a polishing agent for glass and optics.
REEs are commonly divided into “light” and “heavy” groupings, and cerium falls into the group of light REEs. Cerium production is highly concentrated in China, in particular in the Bayan Obo mining district in Inner Mongolia. Because of this concentration, and the utility of cerium in key industries, it is considered a “critical mineral” by the US government and the European Commission.The most significant REE mine outside China is the Mountain Pass mine in California. Work is underway and planned to restore domestic processing capabilities for minerals mined at Mountain Pass, to increase US supply chain security. REE are also mined at the Mount Weld facility in Australia and processed in the Lynas refinery in Malaysia 1 2, which is the only major REE processor outside of China and which provides over 10% of global REE supply. 3 4
Little data is publicly available on cerium production, reserves, price history and recycling rates, as an individual metal, and very few reports on ESG topics discuss cerium by name. At the production and processing stages, public reporting tends to analyse the REEs in aggregate. The supply chain risk risk indicators featured in this profile are not not publicly available for cerium as an individual metal, however scores can be found for REE in aggregate in the corresponding profile.5
While a cursory analysis of ESG risks associated with cerium might produce few results, care should be taken to consider risks that are reported to apply to REE in general, as these will almost certainly apply to cerium specifically too.
Main Uses and Attributes
Cerium oxide is widely used as a chemical catalyst. Many REEs have similar catalytic properties, but cerium is often selected due to its relative abundance and lower price. Cerium is used in catalytic converters for automotive vehicles, which convert exhaust chemicals such as carbon monoxide, nitrogen oxides and hydrocarbons into less harmful substances including elemental nitrogen, carbon dioxide and water vapor.6
Cerium oxide is also used in the automotive industry as a fuel additive. Nanoparticles of cerium oxide can increase fuel efficiency, though studies suggest that inhalation of associated exhaust fumes may cause increased lung damage compared to regular fuel.7
Cerium is used as an alloying element for steel, in which role it improves steel’s durability, including its heat and corrosion resistance, its workability and its mechanical properties.8 9 Cerium can also be used in aluminium alloys, to which it confers the same durability and mechanical properties, as well as making the aluminium more easily castable.10
Another important use of cerium is as a polishing agent. Cerium oxide polish is used to polish automotive glass, optics and gemstones to a very high finish.
Supply Chain Risk
TDi assesses Cerium for key risks affecting the security of supply, and for its association with artisanal and small-scale mining.
Country Governance Risks
Cerium's association with countries experiencing: