Pensana PLC (LSE:PRE, OTC:PNSPF) shares rose 8% to 94.47p after the company said a detailed review of its Longonjo project indicates it can dramatically increase production of high-value heavy rare earths.
The stock is now up about 300% since January.
Longonjo currently produces about 30 tonnes a year of heavy rare earth oxides within its mixed rare earth carbonate.
The new study suggests output could rise to as much as 160 tonnes a year by adding a selective recovery circuit ahead of the precipitation stage.
That would include about 130 tonnes of dysprosium oxide and 30 tonnes of terbium oxide, two of the most valuable rare earth elements used in high-performance magnets for electric vehicles and other advanced technologies.
Pensana said early discussions with potential buyers suggest the richer product mix would increase demand and improve pricing.
Dysprosium oxide trades at around $208,000 per tonne and terbium oxide at nearly $919,000 per tonne, making the upgrade potentially significant for project economics.
Chief executive Tim George said the change would position Longonjo as one of the few near-term projects capable of supplying both light and heavy rare earths into the magnet supply chain.