Innovating rare earth material processing techniques and applications in new technologies


Donald Bubar, President and CEO of Avalon Advanced Materials, and Ian London, Executive Director of C2M2A, discuss the recent developments in rare earth processing in Canada.

In an article on rare earth elements (REE) we posted earlier this year, it was noted that “the 15 lanthanides are very similar chemically and, as such, are difficult to separate using traditional solvent extraction technologies. While this can be done, it is a very expensive process involving multiple circuits in a very large facility.”

Efforts to innovate more efficient rare earth separation process solutions are underway to simplify, reduce costs, and demonstrate more efficient separation process solutions. Progress is being made in Canada.

We are always interested in REE concentration and separation innovations and there continues to be innovation of new applications for REE in new technologies, especially those that utilise the more abundant, currently lower demand rare earths elements such as lanthanum (La) and cerium (Ce).

Increasing La and Ce demand promotes stable REE production and new alloys

Lanthanum and cerium are the most abundant rare earth elements in most rare earth deposits, giving them a relatively low value compared to the REEs used in magnet production; neodymium (Nd), praseodymium (Pr), and dysprosium (Dy). Developing new applications for Ce and La can increase their demand and potentially improve the economics of rare earth mining.

A promising avenue for increasing Ce and La demand is (like scandium) their use in aluminium alloys. Experimental materials science and economic assessments show that Al–La/Ce alloys have elevated mechanical strength compared to more traditional aluminium alloys. In some formulations, they can be used without heat treatment, and possess highly castable eutectic microstructures.

Aluminium alloys are amongst the most energy-intensive materials in widespread structural applications, and their manufacture results in significant emissions and power generation burdens. Heat treating of parts is the most time and energy intensive step in foundry manufacturing, behind melting the metals. Using La/Ce in Al alloys to reduce or eliminate the time and energy use associated with heat treatment should improve foundry economics, lower physical infrastructure needs, and shorten production timelines as demand for high strength aluminium alloys increases.1

In the magnet applications, Toyota cut terbium and dysprosium use in magnets for its 2016 Prius. In addition, Toyota anticipates that up to 50% of the neodymium in the magnets can be replaced with the lower cost La and Ce. How? Innovative manufacturing techniques can reliably reduce the grain size to one-tenth of what is used in current high strength magnets. Nd can then be concentrated on the surfaces of the smaller grains (the grains in standard magnets have the expensive Nd throughout). Inside the grains, Toyota claims that a 1:3 ratio of La to Ce prevents magnet performance from deteriorating. Toyota has stated that the new magnets could reach the market in the first half of the 2020s.2

©iStock/davidf

UCORE advances RapidSX

Earlier this year, Ucore Rare Metals provided an update on its wholly owned RapidSX™ REE separation technology platform and commercial Strategic Metals Complex technology deployment process. The work is taking place at its laboratory partner’s Kingston Process Metallurgy facility in Kingston, Ontario, Canada.

Ucore reported that independent sources have concluded that a RapidSX production plant can potentially have a two thirds smaller footprint than a conventional solvent extraction with the same throughput. This enhanced capability readies Ucore to commercialise RapidSX technology deployment on a faster track. With the increase in RapidSX processing capacity, its demo plant will be able to process a number of feedstock sources, including planned light and heavy REE feedstocks. Work will continue throughout 2022 and into 2023 and is scheduled to conclude with developing a contract design package suitable to execute a design/build construction contract with new rare earth oxide producers commencing in 2024.

Saskatchewan research council creating rare earth processing facility

In August 2020, the Government of Saskatchewan announced C$31m in funding to establish a REE processing facility in Saskatoon that will be owned and operated by the Saskatchewan Research Council (SRC). In June 2022, the Saskatchewan government committed an additional C$20m for the processing facility to expand its capabilities to beyond concentration and separation with the addition of a unit to convert the separated rare earth oxides to the metals because Nd, Pr, and Dy in metallic form are the key ingredients used to manufacture high strength permanent magnets.

SRC has now completed the detailed engineering, design and procurement for the first stage, a Monazite Processing Unit (MPU), to be completed this fall. Procurement for the second stage, the Separation Unit and Metals Unit, is expected shortly thereafter. SRC has also received the first shipment of monazite concentrate, secured from Brazil in late May, with the remainder set to arrive in early July. The monazite concentrate will be used as the feedstock for SRC’s MPU, once operational.

SRC’s efforts are essentially a cornerstone in establishing a vertically integrated REE supply chain in Saskatchewan – an industry model for future commercial REE resource expansion in the province.

Cheetah Resources: REE mining and processing

Cheetah Resources (a wholly owned subsidiary of Australia’s Vital Metals) initiated small-scale production of rare earth mineral (bastnaesite) concentrates in mid-2021 at the Nechalacho REE project in Canada’s Northwest Territories which it co-owns with Avalon Advanced Materials. Vital Metals Canada is building a rare earth extraction plant site in Saskatoon, Saskatchewan, adjacent to the SRC’s Separation facility which it plans to get started next month. Vital has recently commenced feeding ore into a dense media separation plant as part of commissioning of its rare earth extraction facility. They have also reported high-grade results from the first commissioning of the DMS unit that were comparable to the total rare earth oxide grade achieved from laboratory metallurgical test work. With DMS commissioning commenced, over the coming months Vital will incrementally commission the calcination, leaching and purification and precipitation equipment at Saskatoon, with plans to produce a 2.5 tonne rare earth carbonate sample for its inaugural offtake partner REEtec (Norway).

Vital expects to ramp up production volumes at Saskatoon through two stages. Stage 1 is for the throughput capacity of 1,000t/yr REO (ex-cerium), equivalent to 470t/yr NdPr. Stage 2 is set to double capacity. Vital has also established a memorandum of understanding with Ucore for them to supply rare earth carbonate feedstock for Ucore’s facilities.

Despite the abundance of rare earth resources in Canada, it has taken a long time to get a rare earths supply chain started here since Avalon first tried in 2012 when it completed its feasibility study on the Basal Zone resource at Nechalacho. The demand was there in Japan and Korea but after China relaxed the export quotas that had been imposed in 2010, the demand was no longer there. But it was just a matter of time before the demand exceeded the supply again and that time has come. Avalon has maintained ownership of its heavy rare earth rich Basal Zone resource, while Cheetah develops the near surface light rare earth resources, with the intention of re-activating the project once Cheetah gets the supply chain well established here in Canada.

References

1: https://link.springer.com/article/10.1007/s40831-022-00562-4

2: https://cen.acs.org/articles/96/i9/New-Toyota-magnet-cuts-rare.html

Please note, this article will also appear in the eleventh edition of our quarterly publication.


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