Grand Junction, Colorado, Oct. 23, 2019 (GLOBE NEWSWIRE) -- via NEWMEDIAWIRE -- Bullfrog Gold Corp (OTCQB:BFGC and CSE:BFG) (“Bullfrog”, “BFGC” or the “Company”) is pleased to announce high gold recoveries from column leach tests on bulk samples collected from its Bullfrog Project (“Project”) located 125 miles NW of Las Vegas, Nevada.
Metallurgical Testing
During the past 20 months the Company collected four bulk samples from the Bullfrog (BF), Mystery Hill (MH) and Montgomery-Shoshone (MS) pit areas and engaged McClelland Laboratories of Reno, Nevada to complete eleven column and bottle roll leach test on 3/8-inch and finer sizes. The BF 2019 column tests were performed on sample splits that typify most of the 43-101 measured and indicated gold resources on the Project, whereas the BF 2018, MS 2019 and MH 2019 samples represent the smaller balance of remaining resources. Final column leach results are summarized below.
| Column Leach Test Summaries | |||||||
| Deposit | Test Year | Leach Days | Leach Size, p80 | Crush Type | Calc. Head, g/t | Avg. Head Assay, g/t | Gold Rec., % |
| Inch 1 mm | |||||||
| BF | 2018 | 84 | 3/8 9.5 | Conv. | 0.79 | 0.89 | 58.2 |
| 84 | 1/16 1.7 | HPGR | 0.84 | 0.89 | 77.4 | ||
| +19.2 | |||||||
| BF | 2019 | 151 | 3/8 9.5 | Conv. | 1.54 | 1.71 | 75.3 |
| 122 | 1/4 6.3 | HPGR | 1.66 | 1.71 | 77.1 | ||
| 102 | 1/16 1.7 | HPGR | 1.60 | 1.71 | 89.4 | ||
| +14.1 | |||||||
| MS | 2019 | 108 | 3/8 9.5 | Conv. | 0.79 | 0.86 | 65.8 |
| 108 | 1/4 6.3 | HPGR | 0.82 | 0.86 | 76.8 | ||
| 89 | 1/16 1.7 | HPGR 2 | 0.88 | 0.86 | 85.2 | ||
| +19.4 | |||||||
| MH | 2019 | 109 | 3/8 9.5 | Conv. | 0.36 | 0.34 | 83.3 |
| 105 | 1/4 6.3 | HPGR | 0.33 | 0.34 | 87.9 | ||
| 86 | 1/16 1.7 | HPGR 2, 3 | 0.34 | 0.34 | 91.2 | ||
| 1 1/16-inch is approximately 10 mesh 2 Agglomerated with 2 kg cement/mt | +7.9 | ||||||
| 3 The MH material needs more than 2 kg cement/t to create durable agglomerates | |||||||
The -3/8-inch samples were sized using conventional crushers (“Conv.”) and the -1/4 and -1/16-inch samples were further reduced using high pressure grinding rolls (“HPGR”), which can produce finer sizes with much more microfractures that increase gold and silver recoveries. The Bullfrog deposit is highly amenable to leaching exceptionally fine sizes from HPGR’s as the host rocks contain much lower low clay contents than most other gold deposits and do not generate much additional fines during the size reduction processes.
The four column tests sized at -1/16 inch recovered 86% of the gold compared to 71% from the tests at -3/8-inch, or an average 15% increase. The MH 2019 sample at an average grade of only 0.34 g gold/t notably recovered 83% at -3/8-inch Conv. and 91% at -1/16-inch HPGR. The minus 1/16-inch samples in the MS and MH columns each weighed 33.4 kg whereas the nine other column samples each weighed near 71 kg.
Bottle roll tests are not reported herein as they are typically performed on samples of only 1 kg and their indicative results are not as accurate or representative as the larger column tests that closely simulate heap leach production operations. Nonetheless, bottle roll tests are useful for scoping heap leach characteristics and are part of our metallurgical data base.
Load-permeability tests on the MS leached residues indicate that the fine -1/16-inch size can be stacked up to 200 feet high subject to agglomerating with 2 kg of cement/ton. Observation of the two leach tests on the -1/16-inch BF samples suggest that cement agglomeration should be applied. As the agglomerates in the -1/16-inch MH sample degraded by the end of the leach test, a higher cement content is needed for this material. At this time, it appears that the fine size of -1/8-inch may provide the best overall performance. In this regard, the test results performed at -1/16 and -1/4-inch can be interpolated at -1/8-inch with confidence. The 1/8-inch size also allows higher heap heights with less risk of encountering percolation or stability issues than a finer size. In summary, all reagent consumptions were relatively low, and agglomeration does not appear necessary for sizes greater than 1/4-inch.
For reference, column leach tests completed in 1994 by Kappes Cassiday Labs achieved a gold recovery of nearly 76% on 40 kg of representative BF stockwork mineralization averaging 0.99 g/t that was conventionally crushed to -3/8” and leached for 41 days. An 800-ton pilot heap leach test performed by Barrick Bullfrog Inc. in 1995 recovered 67% on similar mineralization averaging 0.65 g/t and conventionally crushed to -1/2”; however, this test would likely have recovered near 76% of the gold had the heap been crushed to -3/8”, leached longer than 41 days and if reported solution distribution issues did not occur.
About Bullfrog Gold Corp.
BFGC is a Delaware corporation that controls the commanding land and mineral positions in the Bullfrog Mine area where Barrick Bullfrog Inc. produced 2.3 million ounces of gold by conventional milling from 1989 into 1999. An independent Canadian National Instrument 43-101 compliant report prepared in August 2017 estimated mineralization at 624,000 ounces at 0.7 g/tonne gold within expanded pit plans based on a gold price of $1,200 and use of heap leaching. The Company obtained a large data base from Barrick, including detailed information on 155 miles of drilling in the area, and has defined BF and MS pit expansions and several prospective exploration targets.
Cautionary Note Regarding Forward Looking Statements
This press release contains certain "Forward-Looking Statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the United States Securities Exchange Act of 1934, as amended. All statements, other than statements of historical fact, included herein including those with respect to the objectives, plans and strategies of the Company and those preceded by or that include the words "believes," "expects," "given," "targets," "intends," "anticipates," "plans," "projects," "forecasts" or similar expressions, are forward-looking statements that involve various risks and uncertainties. Forward looking information in this press release includes but is not limited to statements regarding increased liquidity for the Company’s shareholders and the application of metallurgical testing results.
Such forward-looking information and statements are based on numerous assumptions, including among others, the Company's ability to successfully maintain its listings, the stability of industry and market costs and trends and the Company's ability to obtain all regulatory approvals required for its planned objectives. Furthermore, by their very nature, forward-looking information involves a variety of known and unknown risks, uncertainties and other factors which may cause the actual plans, intentions, events, results, performance or achievements of the Company to be materially different from those expressed or implied by such forward-looking information. Such risks, uncertainties and other factors include, without limitation, those related to: (a) adverse regulatory or legislative changes (b) market conditions, volatility and global economic conditions (c) industry-wide risks (d) the Company's inability to maintain or improve its competitive position and (e) the ability to obtain financing needed to fund the continued development of the Company's business.
We use certain terms in this valuation such as “mineralization” and “mineral inventory estimates” that are not defined in Canadian National Instrument 43-101; or recognized under the U.S. SEC Industry Guide 7. The Company is presently an exploration stage company. Exploration is highly speculative in nature, involves many risks, requires substantial expenditures and may not result in the discovery of mineral deposits that can be mined profitably. Furthermore, the Company currently has no resources or reserves on any of its properties. As a result, there can be no assurance that such forward-looking statements will prove to be accurate, and actual results and future events could differ materially from those anticipated in such statements. Additional information regarding important factors that could cause actual results to differ materially from the Company's expectations is disclosed in the Company's documents filed from time to time with the United States Securities & Exchange Commission. Investors are urged to consider closely the disclosures in our Form 10-K and other SEC filings, which can be obtained from the SEC’s website at http:www.sec.gov/edgar.shtml, or sourced through www.bullfroggold.com.
Qualified Person
David Beling, P.E. has 55 years of project and corporate experience in the mining industry and is a qualified person as defined by Canadian National Instrument 43-101 – Standards of Disclosure or Mineral Projects. Mr. Beling has prepared, supervised the preparation of, or approved the technical information that forms the basis of the Company’s disclosures, but is not independent of Bullfrog Gold Corp, as he is the CEO & President and holds common shares and incentive stock options of the Company.
For further information, please contact David Beling, CEO & President, at (970) 628-1670.