Vancouver, British Columbia--(Newsfile Corp. - September 13, 2018) - Orla Mining Ltd. (TSXV: OLA) ("Orla" or the "Company") is pleased to report positive results from metallurgical column tests on oxide material from its wholly owned Cerro Quema project in Panama. Gold recoveries on material crushed to 150 millimetres were 96% for the La Pava deposit, which contains approximately two thirds of the current mineral reserves, and 91% for the Quemita deposit. Operational recovery estimates are typically de-rated from column test data, but these results compare very favourably to an average operational recovery of 86% in the 2014 Pre-Feasibility Study ("PFS") at a crush size of -70 millimetres. Results will be incorporated into an updated process plan and operational recovery estimates that will consider one-stage crushing or run of mine instead of the two-stage crushing modelled in the 2014 PFS.
Recent metallurgical test work is part of the Company's effort to update the PFS completed on the Cerro Quema Project in 2014. Orla expects to complete the update of the PFS, including new mineral reserve and mineral resource estimates, by mid-2019. In addition to the work on oxide mineralization, Orla will continue to advance exploration of the Caballito copper-gold sulphide discovery. This style of mineralization, identified late last year, presents potential value to the project in addition to the current heap-leach oxide gold project.
Samples for the metallurgical testing program were generated from six HQ-size core holes drilled specifically for metallurgical testing. Three of the holes were drilled in the La Pava deposit and three were drilled in the Quemita deposit which combined host the 488,000 ounce Cerro Quema oxide gold mineral proven and probable reserve (19.7 million tonnes at 0.77 gram per tonne gold)1. Material from the drill holes was combined into two composites, one for La Pava and one for Quemita. Along with a series of characterization test work, both the La Pava and Quemita composites were evaluated to determine a preferred crush size by column leach tests at three different particle sizes (100% passing sizes of 150 mm, 50 mm and 12.5 mm). Test work showed very high recoveries and essentially no difference in recovery by crush size tested. Leach rates were also high, with the bulk of the gold recovered within 20 days.
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1 For more information on the Cerro Quema mineral reserves, please refer to the NI 43-101 technical report "Cerro Quema Project - Pre-Feasibility Study on the La Pava and Quemita Oxide Gold Deposits" published on August 15, 2014 and filed on SEDAR and on the Company's website.
A summary of the results from the column leach tests is presented below:
| KCA Test No. | Description | Crush Size, mm | Calc. Head, gms Au/MT | Tails Assay, gms Au/MT | Extracted, % Au |
| 81716 | Quemita Composite | 150.0 | 0.639 | 0.058 | 91% |
| 81722 | Quemita Composite | 50.0 | 0.444 | 0.053 | 88% |
| 81728 | Quemita Composite | 12.5 | 0.569 | 0.046 | 92% |
| 81719 | La Pava Composite | 150.0 | 1.066 | 0.043 | 96% |
| 81725 | La Pava Composite | 50.0 | 1.046 | 0.052 | 95% |
| 81731 | La Pava Composite | 12.5 | 1.034 | 0.035 | 97% |
In addition to the column leach testing, agglomeration studies and compacted permeability on leached residue samples were performed. It was concluded that agglomeration will not be required and no percolation issues were encountered. To further investigate mine closure and post-mine conditions, composites were tested for environmental characterization and final barren solution and column wash water characterization were included in the testing program. Leached residues were tested by the meteoric water mobility procedure.
Test Work Protocols
The metallurgical test work described in this release was performed by Kappes Cassiday & Associates in Reno Nevada. All sample preparation, solution and solid assaying and metallurgical studies were performed utilizing accepted industry standard procedures. All solid samples are assayed in duplicate and for column leach testing granulated active carbon samples are used to check against daily pregnant and barren leach solution assays completed by Flame Atomic Absorption methods. Solid samples are assayed in small batches along with certified standards, blanks and additional duplicates. Metallurgical mass balances are followed throughout the program with multiple tests completed on each sample to define operating parameters.
Qualified Person
The technical information in this news release has been reviewed and approved by Mr. Hans Smit, P.Geo., Chief Operating Officer of Orla Mining Ltd., who is the Qualified Person as defined by National Instrument 43-101 - Standards of Disclosure for Mineral Projects.
About Orla Mining Ltd.
Orla is developing the Camino Rojo Project, an advanced gold and silver open-pit and heap leach project, located in Zacatecas State, Central Mexico. The project is 100% owned and covers over 200,000 hectares. Access and infrastructure is excellent with a paved highway and powerline nearby. A NI 43-101 Technical Report on Camino Rojo dated June 19, 2018 is available on SEDAR under the Company's profile. Orla also owns 100% of the Cerro Quema Project in Panama which includes a near-term gold production scenario and various exploration targets. Cerro Quema's 14,800-hectare concession is close to infrastructure with easy access to site and strong community support. The Cerro Quema Project is currently in the last stage of the permitting process for a proposed open pit mine and gold heap leach operation. Please refer to the "Cerro Quema Project - Pre-feasibility Study on the La Pava and Quemita Oxide Gold Deposits" dated August 15, 2014, which is available on SEDAR.
Forward-looking Statements
This news release contains certain "forward-looking statements" within the meaning of Canadian and United States securities legislation, including, without limitation, statements with respect to the results of exploration and planned exploration programs, the potential for discovery of additional mineral resources and the Company's objectives and strategies. Forward-looking statements are statements that are not historical facts which address events, results, outcomes or developments that the Company expects to occur. Forward-looking statements are based on the beliefs, estimates and opinions of the Company's management on the date the statements are made and they involve a number of risks and uncertainties. Certain material assumptions regarding such forward-looking statements are discussed in this news release, including without limitation, assumptions that the Company's activities will be in accordance with the Company's public statements and stated goals; that there will be no material adverse change affecting the Company or its properties; that all required approvals will be obtained and that there will be no significant disruptions affecting the Company or its properties. Consequently, there can be no assurances that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements involve significant known and unknown risks and uncertainties, which could cause actual results to differ materially from those anticipated. These risks include, but are not limited to: risks related to uncertainties inherent in the preparation of preliminary economic assessments, drill results and the estimation of mineral resources; and risks associated with executing the Company's objectives and strategies, including costs and expenses. Except as required by the securities disclosure laws and regulations applicable to the Company, the Company undertakes no obligation to update these forward-looking statements if management's beliefs, estimates or opinions, or other factors, should change.
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 news release.
On behalf of the Board of Directors,
Marc Prefontaine, M.Sc., P.Geo.,
President & Chief Executive Officer
For further information, please contact:
info@orlamining.com
www.orlamining.com
