Metallurgical Testing and Drill Data at Bullfrog Golds Nevada Project
GRAND JUNCTION, CO--(Marketwired - Feb 7, 2017) - Bullfrog Gold Corp. (OTCQB: BFGC) ("Bullfrog" or the "Company") has completed an extensive study of comprehensive metallurgical tests and is pleased to announce results that apply directly to the remaining mineralization around the Montgomery-Shoshone (M-S) and Bullfrog open pit mines. The Company is also scanning Barrick Bullfrog Inc.'s paper drill hole files that include assay certificates and other information needed to support Canadian 43-101 compliant resource estimates and open pit expansion plans. In addition, the Company is scheduled to deliver a public presentation on the Bullfrog Project in Beatty, Nevada on March 13, 2017.
The Bullfrog Gold Project is located 120 miles NW of Las Vegas, Nevada and is estimated to contain 470,000 ounces of heap leachable mineralization that averages 0.89 g of gold/tonne within a preliminary pit outline.
Metallurgical Test Results
In 1985 St. Joe Minerals crushed to -3/4 inch a 22-ton composite sample of M-S ore that graded 0.034 opt (1.17 g/tonne) and recovered 56% of the gold after 59 days of column leaching. A second column test recovered 49% after 59 days of leaching, using minus 12 inch Run-of-Mine (ROM) ore grading 0.037 opt (1.26 g/t). Projected 90-day recoveries were 61% and 54% respectively. These columns were 24 feet high and 5.5 feet in diameter and contained representative mineralization remaining in the M-S deposit. St. Joe reported that the ROM sample had 43% of its weight in the minus 1.5 inch fraction, which was higher grade and yielded higher recovery than the coarser fractions. As significant higher grade fines were reported as lost during multiple handling of the samples and because the leach period should have been more than 90 days, St. Joe's recoveries are deemed conservative.
In 1994, Kappes Cassiday, a metallurgical lab in Reno, Nevada, performed column leach tests on low grade ore from the Bullfrog pit. These columns were five feet high, 6 inches in diameter and charged with 45 kg of representative samples. A bottle roll test was also performed on a split of this bulk sample.
Bottle | Column | Column | ||||||||
Crush Size, mesh & inch | -100m | -1.5" | -3/8" | |||||||
Calc. Gold Head, opt | .029 | .035 | .029 | |||||||
g/t | 0.99 | 1.20 | 0.99 | |||||||
Gold Recovery, % | 96.6 | 71.4 | 75.9 | |||||||
Leach time, days | 2 | 41 | 41 | |||||||
Cyanide, #/t | .10 | .77 | 1.07 | |||||||
Lime, #/t | 2.0 | .31 | .35 | |||||||
In 1995, Barrick performed pilot heap leach tests on 844 tons of low grade material from the Bullfrog pit and 805 tons of higher grade from the M-S pit. Both samples were crushed to -1/2 inch and had the following results:
BF Low Grade * | M-S Ore ** | |||||||||
Calc. Gold Head, opt | .019 | .048 | ||||||||
g/t | 0.65 | 1.65 | ||||||||
Projected Au Rec., % | 67 | 74 | ||||||||
Leach time, days | 41 | 37 | ||||||||
NaCn, #/t | .20 | .25 | ||||||||
Lime, #/t | nil | nil | ||||||||
* This composite is deemed representative of the remaining mineralization in the Bullfrog deposit. |
** Most of this higher grade represented by this composite was subsequently milled by Barrick. |
These large pilot tests are deemed the most representative for determining cyanide and lime consumptions, which were remarkably low. In this regard, Barrick reported that the alkalinity in the cyanide additions were sufficient to maintain an acceptable pH with nil lime additions. Notwithstanding, Barrick makes no representation concerning the accuracy or use of their information by the Company.
In summary, the M-S and Bullfrog deposits are amenable to heap leaching and can support a mine cutoff grade of 0.2 g/t for leaching at coarse ROM sizes. The mineralization percolates well, and cyanide and lime consumptions are each projected at less than 0.3 pounds per ton. As the leach times in all column and pilot tests were too short, longer term recoveries are anticipated to be higher.
Drill Data Base
The Company is in process of scanning Barrick's paper drill hole files to obtain copies of assay certificates and update the electronic drill hole data base. In a few weeks, the Company should have all assay and survey data on 1,311 drill holes that contain more than 157 miles of drilling. This complete data base will then be vetted by an independent engineering firm and resources will be estimated in compliance with Canadian 43-101 policies. Pit plans will also be further optimized using computer programs rather than the Company's manual cross section estimation and pit planning methods.
Public Meeting
The Company's President & CEO is scheduled to deliver a public presentation in Beatty, Nevada to the Beatty Town Advisory Board on March 13, 2017 at 6:30 pm. The Company will discuss its exploration and development plans toward advancing the Bullfrog Project and looks forward to building mutually beneficial relationships with the Town and its citizens. Beatty has a population of 1,000 and is only 4 miles east of the Project.
Cautionary Note Regarding Forward Looking Statements
This press release may contain 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. 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 sufficient 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.
Contact
Contact Information:
David Beling, PE,
President, CEO & Director
(970) 628-1670