NioCorp Developments : Announces Second Preliminary Economic Assesment

Economics of Project are Significantly Increased
Scandium Production Increased by 661 Percent
Company Positions to Become a Significant and Reliable Supplier of Scandium

is pleased to announce that it has completed a second Preliminary Economic Assessment (PEA2) for its Elk Creek Niobium Project. The Company will hold an investor call on August 17, 2015 to discuss the preliminary details and the full report will be available for download on the Company's website within 45 days.

Highlights of the PEA2 include:

• Pre-tax NPV of US$3.07 billion.
• Pre-tax IRR of 31.7%.
• After-tax NPV of US$2.30 billion.
• After-tax IRR of 27.6%.
• Average pre-tax cash flow of US$438 million
• An increase in annualized Scandium Trioxide production to 97 tonnes.
• Annualized Ferroniobium production of 7,490 tonnes.
• Annualized Titanium Dioxide production of 23,960 tonnes.
• Total upfront capital investment of US$979 million.

These highlights reflect the "base case" Scandium pricing scenario, which NioCorp has selected to use for the PEA2. The "base case" is taken from an independent Scandium marketing report, prepared for the Company by OnG Commodities. The report provides two cases for Scandium pricing:

• The "base case", which reflects pricing based on the current demand for Scandium from the fuel cell industry, along with the expected adoption of Scandium-Aluminum alloys by the aerospace industry.
• The "slow aerospace case", which reflects a slower uptake of Scandium by the aerospace industry, comparatively.

A comparison of the key project economic indicators for the two Scandium pricing cases appears below:

These highlights also reflect the results of a new independent marketing study for Ferroniobium completed by Roskill Consulting Group Ltd. The same assumptions regarding Titanium Dioxide pricing were used in the PEA2 as were included in the original PEA for the project. The calculations presented above utilize a discount rate of 8%.

During bench and pilot testing of the metallurgical flowsheet for the proposed plant, it was determined that recoveries could be significantly increased by eliminating the flotation step and processing the resource directly through a hydrometallurgical process. The discovery of this positive change to the flowsheet prompted the Company's decision to prepare a new PEA. These changes will ultimately allow the Company to recover significantly higher percentages of all three elements from the resource, including Niobium recovery of 89.2%, Scandium recovery of 90.0%, and Titanium recovery of 87.6%. This in turn will reduce the volume of the resource required to be mined on a daily basis and enable the Company to achieve the same level of Ferroniobium and Titanium Dioxide production, as was noted in the Company's first PEA report, while increasing Scandium Trioxide output by approximately 661%. These changes result in minimal increases to Capex, compared to the first PEA.

"As we conducted our pilot testing and began reviewing the resulting data, it became clear that with elimination of the flotation section and directly leaching the resource in a hydrometallurgical plant we were able to recover a higher percentage of the three payable elements in the resource, with only minimal increases to our upfront capital," said Mark A. Smith, Executive Chairman of NioCorp. "These results clearly support a significantly increased economic valuation of the Elk Creek Project and will assist in our continued efforts to raise the necessary capital to both complete our upcoming Feasibility Study and subsequently begin construction of our mine and processing facilities."

Factors which could affect the Company's final economics include:

• Final market pricing for each of the three product streams - Ferroniobium, Titanium Dioxide and Scandium Trioxide.
• Market demand and uptake rates for Scandium Trioxide by the aerospace industry.
• Final Pyrometallurgical results.
• Final hydrometallurgical results.
• Permitting Progress

Smith further noted, "In an effort to maximize the benefits of these changes, NioCorp plans to work aggressively to secure additional offtake agreements, including agreements for Scandium; finalize pyrometallurgical and hydrometallurgical test work; and continue to evaluate hydrogeologic data that is being generated daily at the project site."

Due to the additional time needed to complete the second Preliminary Economic Assessment, the Company has moved its expected completion date for the full Feasibility Study from the end of the third calendar quarter to at least the end of 2015. The Company continues to pursue the necessary technical programs to complete its Feasibility Study and is currently in the process of raising additional capital to allow its aggressive pace to continue.

The basis for the PEA2 is a 2,700 tonne per day mine production rate over a 32 year operating life with an average grade of 0.80% Nb2O5, 2.84% TiO2 and 73 ppm Sc. Over the operating life, a total of 31.086 million tonnes of the resource would be mined and processed to produce Ferroniobium, Titanium Dioxide and Scandium Trioxide products. The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) compliant resource supporting this production rate was originally disclosed in the Company's press release of February 20, 2015. For the purposes of PEA2, NioCorp has elected to base the mine plan on indicated resources only as opposed to indicated and inferred resources. This decision is in line with the Company's plans to advance the project to the feasibility stage, and is also a reflection of the robust nature of the resource.

Qualified Persons:

Jeff Osborn, BSc Mining, MMSAQP of SRK Consulting (US) Inc., a Qualified Person as defined by National Instrument 43-101, has overall responsibility for SRK portions of the Elk Creek Preliminary Economic Analysis and has read and approved the technical information contained in this news release.

Joanna Poeck, B.Eng., SME-RM, MMSA-QP, a Qualified Person as defined by National Instrument 43-101, is responsible for the Elk Creek mine plan resource and has read and approved the technical information contained in this news release.

Ben Parsons, MSc, MAusIMM (CP) of SRK Consulting (US) Inc., a Qualified Person as defined by National Instrument 43-101, is responsible for the Elk Creek resource estimation and has read and approved the technical information contained in this news release.

Alain Dorval, B.Sc, Roche Consulting Group Limited, a Qualified Person as defined by National Instrument 43-101, is responsible for the Elk Creek mineral processing program and has read and approved the technical information contained in this news release.

Eric Larochelle, B.Eng, Roche Engineering Inc, a Qualified Person as defined by National Instrument 43-101, is responsible for the Elk Creek hydrometallurgical program and has read and approved the technical information contained in this news release.

About NioCorp:

NioCorp is a mineral development Company pursuing high-quality natural resources. The Company's main focus is the Elk Creek Niobium Project, which is an advanced niobium exploration project located in southeast Nebraska. Niobium is used to produce High Strength, Low Alloy ("HSLA") steel, which is a lighter, stronger steel used in automotive, structural, and pipeline applications.

For further information, contact Teresa McGowan, Senior Manager of Investor Relations at (720) 639-4650 or at info@NioCorp.com

Special note about forward-looking statements:
Neither TSX nor its Regulation Services Provider (as that term is defined in the policies of the TSX) accepts responsibility for the adequacy or accuracy of this release.

Certain statements contained in this press release may constitute forward-looking statements. Such forward-looking statements are based upon NioCorp's reasonable expectations and business plan at the date hereof, which are subject to change depending on economic, political and competitive circumstances and contingencies. 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 changes in demand for and price of commodities (such as fuel and electricity) and currencies; 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 labour 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. 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. Readers are advised that the Elk Creek PEA is preliminary in nature and includes Inferred Mineral Resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as Mineral Reserves. There is no certainty that the preliminary economic assessment will be realized. Mineral Resources are not Mineral Reserves because they do not have demonstrated economic viability. There is no guarantee that Inferred Mineral Resources will be converted to the Measured and Indicated Mineral Resource categories and, therefore, there is no guarantee that the project economics described herein will be achieved.