The pair have signed a memorandum of understanding, to evaluate the potential supply of the "very valuable rare earth-bearing material" from Hyperion's Titan project in Tennessee to Energy Fuels' White Mesa mill in Utah.
The two companies said they would also evaluate a potential arrangement to collaborate in the development of a fully integrated "mine to market" US rare earth supply chain.
Energy Fuels said it was evaluating the potential to develop downstream rare earth element (REE) capabilities at White Mesa "or nearby".
The company had announced it was entering the rare earth sector a year ago to complement its core uranium business.
It has since teed up a US-Europe rare earth supply chain.
This was through agreements to acquire monazite from the Chemours Company's Georgia operations and process it at White Mesa to recover uranium and a REE carbonate, then sell this as feed material to TSX-listed Neo Performance Materials for its Europe separations plant manufacturing value-added REE products.
Hyperion's Titan monazite could supplement the Chemours supply, subject to the completion of permitting, development and commencement of operations, the pair said.
Hyperion is aiming for an initial resource at Titan this quarter.
It said phase three drilling and bulk sampling testwork were nearing completion and it was evaluating producing titanium minerals, monazite, zircon and high-quality silica.
"Our collaboration with Energy Fuels highlights the importance of Hyperion's Titan project in the US as a leader in American-sourced critical minerals through its plans to produce zero carbon titanium metals, delivering a clean energy future through the supply of rare earth elements for electric vehicles and the renewable power sectors," MD Anastasios Arima said.
Energy Fuels president and CEO Mark Chalmers said they looked forward to working with the Hyperion team.
"Through their association with Piedmont Lithium's project in South Carolina, members of the Hyperion team have demonstrated to us that they have the know-how and resources to bring US critical mineral projects into production," he said.
Hyperion changed name this month from Tao Commodities.
It had ended 2020 with A$2.5 million in cash and equivalents.
Its shares were up more than 17% in afternoon trade to 96c, near the top of a one-year range, valuing it about $85 million.