FILO MINING REPORTS COLUMN LEACH RECOVERIES OF 93%
Post# of 301275
September 25, 2017: Filo Mining Corp (TSXV, Nasdaq First North: FIL) ("Filo Mining", “Filo”, or the “Company”) is pleased to report positive results from the ongoing metallurgical testwork program on oxide mineralization from the Filo del Sol copper-gold-silver project. A comprehensive program has been underway throughout 2017 based on samples collected during the 2017 field program, including four bulk samples collected from surface exposures of the deposit. The objective of the program is to confirm the previously reported bottle roll leach results under column leaching conditions, and help guide the determination of optimum processing options for the project. Testwork was completed by SGS Canada Inc. in Lakefield, Ontario under the supervision of Dr. Joe C. Ferron and Giovanni Di Prisco, who are consultants to the Company.
In the Gold Oxide zone at Filo del Sol, highlights include:
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Two cyanide column leach tests were completed on surface trench material crushed to 1.5” and ¾”.
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Gold and silver extraction was 92.8% and 69.8% respectively, with very little difference noted between crush sizes.
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Leach kinetics were rapid, with over 90% gold recovery in the first 15 days.
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Variability testing results from seven coarse bottle roll tests (minus 10 mesh) on this material averaged 92.8% gold recovery, and 39.0% silver recovery.
In the Copper-Gold Oxide zone at Filo del Sol, highlights include:
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A sequential leaching process was used to recover copper, gold, and silver – material was acid leached first to recover the copper, followed by rinsing, neutralization, and cyanide leaching for gold and silver recovery.
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Two sequential column leach tests were completed on bulk surface trench material crushed to 1.5” and ¾”.
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Recovery averaged 81.9% copper from acid leaching, followed by 86.7% gold and 70.8% silver from cyanide leaching, with little difference noted between crush sizes.
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Leach kinetics were rapid, with approximately 80% copper recovery in the first 15 days of acid leaching, and over 80% gold recovery in the first 15 days of cyanide leaching.
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Variability testing results from five sequential bottle roll tests (minus 10 mesh) on this material averaged 92.2% copper recovery, 88.2% gold recovery, and 59.9% silver recovery.
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Copper leaching required minimal sulfuric acid addition with several tests leaching under plain water.
In the Silver zone at Filo del Sol:
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Surface trench material for the silver zone was not available, so bottle roll testing was completed on reverse circulation drill cuttings which were not coarse enough for column testing.
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A sequential bottle roll test (80% passing minus 10 mesh) on this material produced 60.8% copper recovery, 63.5% gold recovery, and 72.8% silver recovery.
Several opportunities for future testwork have been identified:
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Rapid extraction of soluble copper suggests a simple washing stage could be used to recover the copper from the copper-gold oxide zone.
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Recoveries have proven relatively insensitive to crush sizing and the Company is planning column leach testing at coarser crush sizes.
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Testing the copper-gold sulphide zone which underlies the other three zones and has not been tested metallurgically yet.
“These early metallurgical column test results confirm our belief that heap leach processing at Filo del Sol is an attractive option,” commented Adam Lundin, President and CEO of Filo Mining. “We are planning to collect additional metallurgical samples during the 2017/2018 field season for variability column testing and to follow-up on some unique opportunities identified. Investigating these opportunities, along with confirming and optimizing the already excellent results, will be the focus of our testwork program moving forward.”
There are an additional two columns currently running on the Filo South copper-gold oxide material. Filo South contains less than 10% of the overall resource, with the bulk of the known resource currently contained at Filo del Sol. Bottle roll tests are also underway for the Filo South gold zone which was recently included in the new resource estimate (see news release dated August 21, 2017 reporting on the updated resource tonnes). In the silver zone, some additional bottle roll tests are underway to test the variability of recovery as it relates to silver head grades. As an alternative option to heap leaching this material, flotation work is also ongoing for the silver zone sample and is expected to guide future trade-off studies on the optimal processing route for this silver zone at Filo del Sol.
2016-2017 Metallurgical Test Program Results
Results of the column leach work conducted at SGS are detailed in Table 1 and 2 below. 6” diameter columns were loaded with material to a height of 6 feet. Prior to cyanide leaching, the material was agglomerated with 12 kg/t cement to ensure there were no percolation issues during the testing. More detailed testwork is required to confirm the agglomeration requirements (if any) for the various feed materials.
Table 1: Filo del Sol Gold Oxide (FDS AuOx) Column Test Results
Head Assay | Recovery | Reagent Consumption | |||||
Test No. | Sample | Au (gpt) | Ag (gpt) | Au (%) | Ag (%) | NaCN (kg/t) | CaO (kg/t) |
C5 | FDS AuOx – 1.5” | 1.15 | 6.25 | 92.7 | 74.4 | 0.51 | 4.6 |
C6 | FDS AuOx – ¾” | 1.15 | 6.25 | 92.9 | 65.2 | 0.40 | 6.2 |
Average | 92.8 | 69.8 | 0.46 | 5.4 |
- Total leach time = 39 days
Table 2: Filo del Sol Copper Gold Oxide (FDS CuAuOx) Sequential Column Test Results
Head Assay | Recovery | Reagent Consumption | ||||||||
Test No. | Sample | Cu (%) | Au (gpt) | Ag (gpt) | Cu (%) | Au (%) | Ag (%) | H2SO4 (kg/t) | NaCN (kg/t) | CaO (kg/t) |
C7 | FDS CuAuOx – 1.5” | 0.31 | 0.69 | 2.0 | 80.5 | 86.4 | 74.4 | ~0 | 0.73 | 4.6 |
C8 | FDS CuAuOx – ¾” | 0.31 | 0.69 | 2.0 | 83.3 | 87.0 | 67.2 | ~0 | 0.76 | 4.6 |
Average | 81.9 | 86.7 | 70.8 | ~0 | 0.75 | 4.6 |
- Total acid leach time was 19 days
- Material was then washed / neutralized for an additional 8 days
- Total cyanide leach time was 39 days
- Total time from start of acid leaching through end of cyanide leaching = 66 days
QUALIFIED PERSONS
Dr. Giovanni Di Prisco, P.Geo., is the Qualified Person as defined by National Instrument 43-101. Dr. Di Prisco is a consultant for the Company and has verified the technical information for the Filo del Sol Project included and relating to the tests from which the results are reported in this press release.
ABOUT FILO MINING CORP.
Filo Mining’s flagship project is its 100% controlled Filo del Sol Project located on the border between San Juan Province, Argentina and Region III, Chile. Filo del Sol is located between the prolific Maricunga and El Indio Gold Belts, two major mineralized trends that contain such deposits as Caspiche, La Coipa, Veladero, El Indio, and Pascua Lama. The region is mining-friendly and hosts a number of large scale mining operations. The project area is covered under the Mining Integration and Complementation Treaty between Chile and Argentina, which provides the framework for the development of cross border mining projects.
ADDITIONAL INFORMATION
Filo Mining is listed on the TSX-V and Nasdaq First North Exchange under the trading symbol "FIL". Pareto Securities AB is the Company's Certified Adviser on Nasdaq First North.
This information was submitted for publication, through the agency of the contact person set out below, on September 25, 2017 at 2:00 a.m. Toronto Time.
On behalf of the Board of Directors of Filo Mining,
Adam I. Lundin
President and CEO
For further information, please contact: Sophia Shane, Investor Relations (604) 689-7842.
Neither 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.
Cautionary Note Regarding Forward-Looking Statements
Certain statements made and information contained herein in the press release constitutes “forward-looking information” and “forward-looking statements” within the meaning of applicable securities legislation (collectively, “forward-looking information”), concerning the business, operations and financial performance and condition of Filo Mining Corp. The forward-looking information contained in this press release is based on information available to the Company as of the date of this press release. Except as required under applicable securities legislation, the Company does not intend, and does not assume any obligation, to update this forward-looking information. Generally, this forward-looking information can frequently, but not always, be identified by use of forward-looking terminology such as "plans", "expects" or "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or variations of such words and phrases or statements that certain actions, events, conditions or results “will”, "may", "could", "would", "might" or "will be taken", "occur" or "be achieved" or the negative connotations thereof.
All statements other than statements of historical fact may be forward-looking statements. Forward-looking information is necessarily based on estimates and assumptions that are inherently subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of the Company to be materially different from those expressed or implied by such forward-looking information, including but not limited to: risks and uncertainties relating to, among other things, the inherent uncertainties regarding cost estimates, changes in commodity prices, currency fluctuation, financing, unanticipated resource grades, infrastructure, results of exploration activities, cost overruns, availability of financing, materials and equipment, timeliness of government approvals, taxation, political risk and related economic risk and unanticipated environmental impact on operations, as well as other risks and uncertainties more fully described under "Risk Factors" and elsewhere in the Company's most recent Annual Information Form available under the Company's profile at www.sedar.com and on the Company's website. These risks and uncertainties may cause the actual results, level of activity, performance or achievements of the Company to be materially different from those expressed or implied by such forward-looking information.
The Company believes that the expectations reflected in the forward-looking information included in this press release are reasonable but no assurance can be given that these expectations will prove to be correct and such forward-looking information should not be unduly relied upon. This forward-looking information speaks as of the date of this press release. Forward-looking information in this news release includes, but is not limited to, statements regarding the Company’s expectations with respect to the timing of the PEA, the assumptions used in the mineral resource estimates for the Filo del Sol project; expected timing with respect to a decision on whether to proceed towards a PFS, expectations with regard to processing methods, potential for adding to mineral resources through exploration; estimations of commodity prices, mineral resources, and costs.
Statements relating to "mineral resources" are deemed to be forward looking information, as they involve the implied assessment, based on certain estimates and assumptions that the mineral resources described can be profitably produced in the future.
Forward-looking information is based on certain assumptions that the Company believes are reasonable, including that the current price of and demand for commodities will be sustained or will improve, the supply of commodities will remain stable, that the general business and economic conditions will not change in a material adverse manner, that financing will be available if and when needed on reasonable terms and that the Company will not experience any material labour dispute, accident, or failure of plant or equipment. These factors are not, and should not be construed as being, exhaustive. Although the Company has attempted to identify important factors that would cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated, or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. All forward-looking information contained in this document is qualified by these cautionary statements. Readers are cautioned not to place undue reliance on forward-looking information due to the inherent uncertainty thereof.