NioCorp to Analyze Additional Elk Creek Drill Core as it Looks to Further Enhance, Upgrade, and Add Rare Earth Data to the Elk Creek Project's Mineral Resource

The Conservation and Survey Division of the University of Nebraska Lincoln's School of Natural Resources is Providing NioCorp Access to Historic Drill Core from the Site to Facilitate Core Assay Tests in September and October 2021

CENTENNIAL, Sept. 9, 2021 - NioCorp Developments Ltd. ("NioCorp" or the "Company") (TSX:NB) (OTCQX:NIOBF) is pleased to announce that it will analyze historic drilling core samples from the Elk Creek deposit in southeast Nebraska in order to compile sufficient data with the aim of publishing an updated Mineral Resource for the Elk Creek Critical Minerals Project (the "Project") that includes individual rare earth elements ("REEs") grades and tonnage that may exist in the deposit.

NioCorp is currently conducting extensive metallurgical testing to demonstrate, among other things, the potential extraction and recovery of REEs from the Project site, subject to receipt of necessary project funding.

Updating the Project's Mineral Resource is a significant step forward in the Company's examination of the technical and economic feasibility of adding several REEs as byproducts to its planned product suite, which includes the critical minerals niobium, scandium, and titanium. The Company's REE initiative was launched in response to intense interest by governments and industrial consumers around the world for additional sources of rare earths beyond current suppliers.

Publicly issuing an updated Mineral Resource that includes individual REE grades and tonnage data contained in the Elk Creek deposit is not expected to require updating other major elements of the Project's current Feasibility Study.

Commercial rare earth products currently being examined for potential production by NioCorp include neodymium-praseodymium oxide ("NdPr"), dysprosium oxide ("Dy2O3"), and terbium oxide ("Tb4O7"). These are the primary rare earth elements used to manufacture the world's most powerful permanent magnets, known as neodymium-iron-boron ("NdFeB") magnets.

"Metallurgical testing to date has shown excellent preliminary results in terms of the efficiency with which we believe we can extract rare earths as a byproduct of our current production plans," said Scott Honan, Chief Operating Officer of NioCorp. "Taking this next step of updating our Mineral Resource and including rare earth grades and tonnages in the Resource, to the extent REEs qualify for reporting as a Mineral Resource, will help us move forward in this process and should provide the public with more information on the rare earth potential of the Elk Creek carbonatite. I look forward to seeing the results of additional core sampling."

"I also want to thank the University of Nebraska-Lincoln for its support of this effort and for the UNL's Conservation and Survey Division's many years of involvement in the assessment of the world-class carbonatite near Elk Creek," he added.

Extensive drilling of the Elk Creek resource has been conducted by NioCorp and other companies over the past several decades. Some of the drill core from that exploratory drilling is stored and curated in a repository of the University of Nebraska's. UNL's Conservation and Survey Division ("CSD") is a unique, multi-disciplinary research, service and data-resource organization that originated in 1893. As Nebraska's geological survey, its mission is to investigate and record information about the state's geologic history, its rock and mineral resources, the quantity and quality of its water resources, land cover, and other aspects of its geography, as well as the nature, distribution and uses of its soils.

CSD was actively involved in the discovery of the Elk Creek carbonatite more than five decades ago. CSD continues to curate samples and data from the deposit, among its many other collections, for the benefit of stakeholders and in the public interest. CSD has been an invaluable source of data and expertise for minerals development and other Earth-science issues in Nebraska since its founding.

@NioCorp $NB $NIOBF #ElkCreek #Niobium #Scandium #Nebraska #rareearth #UNL #CSD

For More Information:

Contact Jim Sims, VP of External Affairs, NioCorp Developments Ltd., 720-639-4650, jim.sims@niocorp.com

About NioCorp

NioCorp is developing a superalloy materials project in Southeast Nebraska that will produce Niobium, Scandium, and Titanium. The Company also is evaluating the potential to produce several rare earth byproducts from the Project. Niobium is used to produce superalloys as well as High Strength, Low Alloy ("HSLA") steel, which is a lighter, stronger steel used in automotive, structural, and pipeline applications. Scandium is a superalloy material that can be combined with Aluminum to make alloys with increased strength and improved corrosion resistance. Scandium is also a critical component of advanced solid oxide fuel cells. Titanium is used in various superalloys and is a key component of pigments used in paper, paint and plastics and is also used for aerospace applications, armor, and medical implants. Magnetic rare earths, such as Neodymium, Praseodymium, Terbium, and Dysprosium are critical to the making of Neodymium-Iron-Boron ("NdFeB") magnets, which are used across a wide variety of defense and civilian applications.

Forward-Looking Statements Disclaimers

Certain statements contained in this news release may constitute forward-looking statements, including statements regarding the success of the Company's effort to sample additional Elk Creek drill core, its ability to complete and issue an updated Mineral Resource for the Project, to the extent REEs qualify for reporting as a Mineral Resource, its ability to produce commercial rare earth products, the Company's expectations that the Project will reach production stage if it is able to secure project financing, and its ability to produce its planned products commercially. Readers are cautioned that such forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause a change in such assumptions and the actual outcomes and estimates to be materially different from those estimated or anticipated future results, achievements or position expressed or implied by those forward-looking statements. Risks, uncertainties and other factors that could cause NioCorp's plans or prospects to change include risks related to the Company's ability to operate as a going concern; risks related to the Company's requirement of significant additional capital; changes in demand for and price of commodities (such as fuel and electricity) and currencies; changes in economic valuations of the Project, such as Net Present Value calculations, changes or disruptions in the securities markets; legislative, political or economic developments; the need to obtain permits and comply with laws and regulations and other regulatory requirements; the possibility that actual results of work may differ from projections/expectations or may not realize the perceived potential of NioCorp's projects; risks of accidents, equipment breakdowns and labor disputes or other unanticipated difficulties or interruptions; the possibility of cost overruns or unanticipated expenses in development programs; operating or technical difficulties in connection with exploration, mining or development activities; the speculative nature of mineral exploration and development, including the risks of diminishing quantities of grades of reserves and resources; and the risks involved in the exploration, development and mining business and the risks set forth in the Company's filings with Canadian securities regulators at www.sedar.com and the SEC at www.sec.gov. NioCorp disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events, or otherwise.

View original content to download multimedia:https://www.prnewswire.com/news-releases/niocorp-to-analyze-additional-elk-creek-drill-core-as-it-looks-to-further-enhance-upgrade-and-add-rare-earth-data-to-the-elk-creek-projects-mineral-resource-301372607.html

SOURCE NioCorp Developments Ltd.