NioCorp Acquires Scandium Alloy Assets to Support Potential First-Ever Vertically Integrated U.S. Scandium Mine-to-Markets Supply Chain (Form 8-K)

NioCorp Acquires Scandium Alloy Assets to Support Potential First-Ever Vertically Integrated U.S. Scandium Mine-to-Markets Supply Chain

Acquisition of the Manufacturing Assets and IP from FEA Materials is Expected to Position NioCorp to Produce Master Alloy as Defense and Commercial Market Demand Grows

Once its Elk Creek Critical Minerals Project is Fully Financed and Operational, NioCorp Will be Positioned to Operate a Vertically Integrated Domestic Scandium Mine-to-Markets Supply Chain

NioCorp Also is Examining the Feasibility of Integrating Down to the Production of Finished Aluminum-Scandium Alloy Parts via Casting, Forging and Machining for OEM Manufacturers in Defense and Commercial Markets

CENTENNIAL, Colo. (December 4, 2025) - NioCorp Developments Ltd. ("NioCorp" or the "Company") (NASDAQ: NB), a leading U.S. critical minerals developer, is pleased to announce that it has completed the purchase of the manufacturing assets and intellectual property ("IP") of Massachusetts-based FEA Materials LLC ("FEA"), which is expected to enable NioCorp to produce aluminum-scandium ("Al-Sc") master alloy in the U.S. as market demand grows. Once its Nebraska mine and processing facility are fully financed and operational, the acquisition positions NioCorp to establish America's first scandium supply chain that vertically integrates mining, scandium oxide production, and Al-Sc master alloy production for both defense and commercial manufacturers.

NioCorp Advanced Metals and Alloys LLC ("NAMA"), a newly formed subsidiary of NioCorp and its operating company Elk Creek Resources Corp. ("ECRC"), completed the all-cash $8.4 million purchase of FEA's assets and IP on December 4, 2025. FEA has been engaged in the commercial manufacturing of 2% - 4% Al-Sc master alloy via an innovative process that converts scandium oxide directly into Al-Sc master alloy, bypassing the interim step of first converting the oxide into metal before making Al-Sc master alloy.

NioCorp plans to begin mining scandium-containing ore and producing scandium oxide at its Elk Creek Critical Minerals Project in Nebraska as soon as possible, contingent upon final project financing and construction. In addition to scandium, NioCorp also intends to produce niobium and titanium products and, potentially, light and heavy rare earth oxides in Nebraska.

NioCorp Developments Ltd., 7000 S. Yosemite, #115, Centennial CO 80112 | (720) 334-7066 | www.niocorp.com

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On August 5, 2025, it was announced that the Pentagon's Title III Program had agreed to provide ECRC with up to $10 million in funding to advance the Elk Creek Critical Minerals Project and to support the production of scandium oxide. (See this announcement). Following that award, ECRC entered into a collaboration with Lockheed Martin on the design, testing, and production of airworthy aluminum-scandium parts for advanced fighter jets and other aerospace platforms. (See this announcement). Finally, the Pentagon award also included funding to allow ECRC to demonstrate the ability to convert scandium oxide into high-purity scandium metal, used in advanced electronics applications for both defense and commercial applications.

"We are extremely grateful for the Pentagon's support in our effort to build out this supply chain, and we are now pleased to invest our own resources to leverage the Pentagon's investment and further build out this U.S. domestic supply chain," Mr. Smith said. "Working jointly with the Pentagon, NioCorp is committed to positioning America to better insulate our nation from years of scandium market and price manipulation by the People's Republic of China, which has held back the development of many scandium-based technologies that would greatly benefit our men and women in uniform."

Mr. Smith also praised Rio Tinto, through its Element 21 North subsidiary, for its production of scandium oxide and Al-Sc master alloy at its facility in Sorel-Tracy, Quebec. "Rio Tinto has served as a commercial pioneer in the development of a North American supply chain and deserves a lot of credit for making scandium available for several developing markets and applications of importance to the U.S."

Prospective U.S. Scandium Mine-to-Markets Supply Chain

The development of a complete U.S. domestic scandium mine-to-markets supply chain is likely to include the following components. NioCorp is examining the feasibility of operating across several portions of this prospective supply chain.

NioCorp Developments Ltd., 7000 S. Yosemite, #115, Centennial CO 80112 | (720) 334-7066 | www.niocorp.com

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Qualified Persons:

Scott Honan, M.Sc., SME-RM, COO of NioCorp Developments Ltd., a Qualified Person as defined by National Instrument 43-101, has reviewed and approved the technical information contained in this news release.

NioCorp Developments Ltd., 7000 S. Yosemite, #115, Centennial CO 80112 | (720) 334-7066 | www.niocorp.com

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FOR MORE INFORMATION:

Jim Sims, Corporate Communications Officer, NioCorp Developments Ltd., (720) 334-7066, [email protected]

@NioCorp $NB #Niobium #Scandium #rareearth #neodymium #dysprosium #terbium #ElkCreek

ABOUT NIOCORP

NioCorp is developing the Elk Creek Project, which is expected to produce niobium, scandium, and titanium. The company is also assessing the potential to produce several rare earth elements from the project. Niobium is used to create specialty alloys and High-Strength, Low-Alloy ("HSLA") steel, a lighter, stronger steel used in automotive, structural, and pipeline applications. Scandium is a specialty metal that can be combined with aluminum to make alloys with increased strength and better corrosion resistance. It is also a critical component of advanced solid oxide fuel cells. Titanium is used in various lightweight alloys and is a key ingredient in pigments for paper, paint, and plastics. It is also utilized in aerospace, armor, and medical implants. Magnetic rare earths, such as neodymium, praseodymium, terbium, and dysprosium, are essential for making neodymium-iron-boron magnets, which are used in many defense and civilian applications.