Researchers from the US government's National Engineering Technology Laboratory (NETL) have developed a process by which waste products from coal can be converted into graphite.
Graphite is widely used in a range of energy applications including battery electrodes and nuclear power, as well as in steel production. Its importance in manufacturing, combined with the limitations in supply mean that graphite is classified as a critical mineral in the US. The work carried out by NETL will support the US in maintaining its supply of this material.
The research team says that a key element of its low-temperature synthesis process is that it uses readily available catalyst materials, such as iron, in the production of highly crystalline graphite. In addition the process can use a range of coal waste feedstocks including coal char, bio-char, petroleum coke and even plastic waste.
The new catalyst from NETL results in a manufacturing process that is not only quicker than conventional catalytic processes, but also requires less heat. Research also demonstrates that the catalyst can be recovered, recycled and reused 'indefinitely', NETL said, which improves the overall economics of graphite production.
Ki-Joong Kim, research scientist in the materials engineering and manufacturing division of NETL, and principle investigator on the catalytic process said: “The low temperature synthesis of graphite from coal and coal waste could lead to a new cost-effective domestic industrial manufacturing base for this critical material. This could be a splendid asset in the tool box of the American economy as new graphite sources and production methods are needed more than ever.”
The researchers say that around one-third of the global market is supplied using natural graphite, with the remaining two-thirds of global supply based on synthetic graphite. Production of both natural and synthetic graphite is concentrated in China, which currently accounts for 70% of the world’s production of natural graphite and 60% of the world’s synthetic graphite. Natural graphite has not been mined in the US since 1990, while the production of synthetic graphite has been climbing.
Leveraging its critical minerals expertise, NETL is also supporting the establishment of the Critical Minerals Leadership Academy (CMLA), a programme focused on building capacity and expertise in the field.
Critical minerals and materials (CMM), including rare earth elements (REE), are essential for virtually all modern technology, including those used in hydrocarbon energy production and national defence. However, the US currently imports more than 80% of its supply.
Scott Montross, one of NETL’s technology managers overseeing the critical minerals and materials program said: “To meet these goals, we will need to cultivate world-class experts and build foundational collaborations across the nation. The CMLA aims to do just that — assemble future leaders with diverse backgrounds to build a strong domestic critical minerals network and contribute to the build-out of the United States CMM industry.”
Further supporting critical mineral and material research, the NETL has also launched ClaiMM, which it describes as the "first and only digital platform dedicated to supporting US research across the full critical minerals and materials value chain, unlocking digital tools and data from source to supply." NETL says that ClaiMM gives CMM researchers access to curated CMM datasets, databases, models, tools and services within a secure digital research library. The platform also enables cross-sector collaboration and rapid innovation across the CMM ecosystem.
Further reading
- Critical minerals: Harnessing AI to improve discovery and supply
- Critical minerals: UK unveils plan to boost production
- Critical minerals: UK lags, China dominates, and parliament demands a plan
- Critical minerals: Why recycling is the key
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