The Lofdal heavy rare earth project has the potential to be a "significantly" bigger operation than the previous studies, with Namibia Critical Metals on Monday unveiling the results of a new preliminary economic assessment (PEA).

The new PEA works on a larger yearly run-of mine (RoM) and plant throughput of two-million tonnes a year and a longer mine life than the historical PEA of 2014, by including two sub-deposits, namely Pit 2B and Pit 4.

Further, the processing flow sheet was simplified to a direct flotation of the RoM material and expanded to include a hydrometallurgical unit producing more than 98% mixed rare-earth oxide (REO) as a final product, instead of xenotime concentrate.

The new PEA gave Lofdal a net present value (NPV) of $391-million after tax and an internal rate of return (IRR) of 28%. This compares with the 2014 PEA, which concluded that the project would have the potential to produce an average of 1 500 t/y of separated REO, with an NPV, using a 10% discount, of $148-million, and an IRR of 42%.

The 2022 study estimated initial capital costs, with a 30% contingency, at $207-million, with a payback of 3.2 years.

Lofdal will produce 2 000 t/y of total REO, including 117 t/y of dysprosium and 17.5 t/y of terbium.

“This is a major step forward in establishing Lofdal as a world-class heavy rare project and a globally significant potential supplier of dysprosium and terbium, the two most valuable rare earth metals,” said Namibia Critical Metals president Darrin Campbell.

The price of dysprosium oxide is $587/kb and terbium oxide is $2 493/kg. The average basket price is $91/kg, including third-party separation costs.

The PEA is based on mining only 26-million tonnes of resource, or about 50% of the 53-million tonnes in the mineral resource estimate of June 2021. The project will have a mine life of 16 years, with 13-million tonnes of low-grade stockpile which could expand the life-of-mine.

Campbell said that economic analysis of the PEA supported the continued development of Lofdal, with the prefeasibility study to be advanced over the coming months.

Processing test work is continuing, and it is expected to further significantly improve recoveries, which will allow the Lofdal project to become one of the major future sources of dysprosium and terbium globally, he added.

The project is being developed in joint venture with Japan Oil, Gas and Metals National Corporation, targeting a long-term, sustainable supply of heavy rare earths to Japan.

Namibia Critical Metals’ share price surged by one-quarter on the TSX-V on Monday, ending at C$0.15 apiece.