Rosita's Santa Rita Project Preliminary Economic Assessment Study Demonstrates a 10-year project that returns 41% IRR after Government Royalty and Taxes

The PEA is preliminary in nature and it includes Indicated and Inferred resources in the Stockpiles and Tailings Resources as disclosed by the Company's February 8, 2016 NI 43-101 Technical Report (filed on SEDAR March 22nd 2016). The Inferred Resources are too speculative geologically to have economic considerations to be applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

The Resources estimated and the results of the testwork and engineering previously disclosed, allowed the following Project to be defined for the PEA:

• -Anticipated Life of Mine of 10 years, utilizing 4.67 million tonnes of the material included in the resource tabulation categorized as Indicated Mineral Resources grading at 0.51 grams per tonne gold, 8.2 grams per tonne silver and 0.59% copper and 1.53 million tonnes categorized as Inferred Mineral Resources grading at 0.61 grams per tonne gold, 11.3 grams per tonne silver and 0.65% copper.

  -Anticipated capacity of the Treatment plant (milling plus heap leach) of 1,000 tonnes per day for the first 3 years, expanding to 2,000 tonnes per day for the subsequent 7 years.

The metal prices assumed for the economic Model are:-

• -Gold: USD$1250 per ounce

  -Silver: USD$18 per ounce

  -Copper: USD$2.50 per pound.

Other criteria, assumptions and conclusions from the PEA may be summarised:

• -Pre-production capital costs including 30% contingencies, $11.4 Million

  -Total capital over life of mine including 30% contingencies, $26.1 Million

  -Operating costs over the life of mine per tonne of throughput, $ 18.5 per tonne

  -The Nicaraguan royalty rate of 3% NSR and 0.5% to an independent 3rd party applied to all saleable products.

  -The Nicaraguan income tax rate of 30% after depreciation of fixed assets at 10%

  -IRR after all government taxes 41%;

  -NPV at 7%, after all government taxes $33.9 million;

  -Pay back of initial pre-production capital after all taxes 2.6 years

John Cook, President and CEO commented that "the stockpiles and tailings were accumulated on the ground by the Santa Rita Mine that closed in 1978, when copper prices were low and the treatment plant was not really suitable for the copper and gold ore. Recent innovative work using SGS Lakefield and preliminary engineering by D.E.N.M. Engineering Ltd., has allowed Rosita to design a modern treatment plant and construct the resulting Project Model, which is very positive. The project only uses 72% of the indicated mineral resources and 28% of the inferred mineral resources in the resources tabulation. The economics relating to the balance of indicated mineral resources and inferred mineral resources have not been sufficiently studied for inclusion in the Model at this time."

In Nicaragua, Rosita has commenced environmental base line work to prepare the project for Mine Permit Application. Social Responsibility work has been undertaken positively with the Municipality.

John Cook added that in addition to the production scenario, the Project contains significant exploration targets which have been disclosed in the past by Alder Resources Ltd., prior to its having been acquired by Rosita. Over many years, the Rosita D Concession has been regarded as an important exploration project area, which is surrounded by active exploration programs operated by others.

The preparation of the PEA resulted in no changes to the quantity of mineral resources previously disclosed. However, in accordance with the requirements of National Instrument 43-101 - Standards of Disclosure for Mineral Projects, the Company will file an updated technical report reflecting the results of the PEA. This will be filed within 45 days.

Qualified Persons

The contents of this news release are based upon the PEA prepared by or under the supervision of David Salari (P.Eng.) the president of D.E.N.M. Engineering Ltd. and a Qualified Person for purposes of NI 43-101, except for references to the mineral resources, which have been previously disclosed in the Company's technical report referred to below. Testwork has been done at SGS, Lakefield, who have reported accordingly. The conclusions from the testwork and their inclusion into the Treatment Plant preliminary engineering have been undertaken by D.E.N.M. Engineering Ltd.

John Cook, MIMMM, Qualified Person, as defined by NI-43-101, has also read and approved the contents of this press release.

Related disclosure documents:

• -NI43-101 Technical Report titled Mineral Resource Estimate For Rosita Stockpiles and Tailings Rosita Cu-Au-Ag Project, Region Autonoma de la Costa Caribe Norte, Nicaragua, dated effective February 8, 2016

  -News release dated March 21st, 2016 - "Rosita Mining Advancing Copper and Gold RecoveryStudies for its Stockpile Resources in Nicaragua"

  -News release dated March 22nd, 2016 - "Rosita Mining files National Instrument 43-101 Report"

  -News release dated May 31st, 2016 - "Rosita Mining provides Update on Stockpile and Tailings Project in Nicaragua"

  -News release dated September 19th, 2016 - "Rosita Mining Santa Rita Project Returns Positive Metallurgical Results"

  -News release dated January 11th, 2017 - "Rosita Mining Santa Rita Project - Updated Metallurgical Results"

The Santa Rita Mine closed in 1978. This Project is a joint venture between Rosita Mining (67%) and Calibre Mining Corp., (CXB: TSX.V) (33%).

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

About Rosita Mining Corporation

Rosita is a junior mining and exploration resource company focused on growing shareholder value through the development of the Santa Rita Stockpiles and tailings and advancing accretive exploration opportunities.

Rosita and Calibre hold 67 % and 33 % interest respectively in the Rosita copper-gold-silver supergene/skarn/porphyry project in Nicaragua located 275 kilometres northeast of Managua.

Forward-Looking Information

This news release contains forward-looking information which is not comprised of historical facts. Forward-looking information involves risks, uncertainties and other factors that could cause actual events, results, performance, prospects and opportunities to differ materially from those expressed or implied by such forward-looking information. Forward looking information in this news release includes, but is not limited to, the Company's ongoing Project development, all of the assumptions included in the PEA, including with respect to metal prices, royalty rates, taxation rates, operating costs and capital costs. Factors that could cause actual results to differ materially from such forward-looking information include, but are not limited to, the preliminary nature of a PEA, failure to obtain necessary environmental permits, metal prices, royalty rates, taxation rates, operating costs and capital costs being different that what the Company currently anticipates, unanticipated engineering difficulties and political risk, general business and economic uncertainties, future mineral prices and adverse market conditions, as well as those risks set out in the Company's Management Discussion and Analysis filed on SEDAR. Although the Company believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur. The Company disclaims any intention or obligation to update or revise any forward-looking information, whether as a result of new information, future events or otherwise, other than as required by law.

For further information, contact:

John Cook, President and CEO
Telephone: +1 416 200 8073
Email: johncook@kos.net

Copyright (c) 2017 TheNewswire - All rights reserved.