VANCOUVER, British Columbia, July 10, 2023--(BUSINESS WIRE)--Western Exploration Inc. (TSXV: WEX; OTCQX: WEXPF) (the "Company" or "Western Exploration") is pleased to announce the results from its ongoing metallurgical heap leach test program designed to determine the processing characteristics at Doby George. Bottle roll recoveries from the various crush sizes sampled returned positive results that will form the basis for compositing mineralization for additional column leach test work at Doby George.
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Figure 1. Plan view map showing location of Doby George drill holes for composite bottle roll results listed in Table 1, and highlighting assays reported in Western Exploration's news releases dated, October 26, 2022, December 8, 2022 and January 17, 2023. (Graphic: Business Wire)
Agitated cyanidation bottle roll test work was completed on 46 composites generated from samples collected during the 2022 PQ drill program completed in 2022 (refer to Table 1 and Figure 2 for detailed test results).
The composites ranged in grade from 0.17 g/t Au to 9.38 g/t Au and averaged 2.36 g/t Au and cyanide soluble gold-to-fire assay ratios (CN/FA) were generally above 80% (see news release of January 17, 2023).
Average gold extraction of oxide mineralization of 69.3% from the agitated cyanidation bottle roll leach test work.
The oxide composites generally did not contain detectable sulfur and composites from West Ridge Deep (Mixed) only contained approximately 0.07% to 0.2% sulfide sulfur.
Reagent consumption was consistently low and is expected to be low for commercial heap leaching, averaging 0.12 kg/ton for cyanide and 0.9 kg/ton for lime.
Western Exploration CEO, Darcy Marud, commented: "It's an exciting time for the Doby George deposit following our exploration success in 2022. In 2022, the exploration team drilled nine holes with the goal of further delineating and advancing the existing mineral resource at the Aura Project. Doby George hosts 407k Gold ounces in the indicated category (12.9k tonnes at 0.98 g/t) and 119k Gold ozs in the inferred category (4.99k tonnes at 0.73 g/t).
"The metallurgical test results that support heap leach gold recoveries of approximately 70% are in line with the extensive historical exploration and metallurgical test results generated by previous owners of the deposit, including Atlas Corporation, Homestake Mining Company and Independence Mining Company. It is anticipated that the results of the metallurgical heap leach test program will be used to support the preparation of a Pre-Feasibility Study on the Doby George deposit in 2024, pursuant to which the Company expects to update its existing mineral resource estimate and underline potentially robust project economics supported by surface outcrops and the recent metallurgical test results. Doby George is a very exciting resource for Western Exploration and we still have extensive exploration upside on the property, particularly at Gravel Creek where our 2023 drill program is focused."
Table 1. Summary Results of Bottle Roll Tests at Doby George Variability Composites(1)
Au Recovery %
Head Grade, gAu/mt
West Ridge Oxide
West Ridge Deep Oxide
West Ridge Deep Mixed
Twilight Oxide Mixed
Bottle roll cyanide leach test was conducted on each composite at an 80% - 1.7 mm feed size, with a 1.0 g/L NaCN concentration and a 4 day leach cycle.
The Doby George variability composites were amenable to agitated cyanidation treatment at the 80% - 1.7mm feed size, indicating good potential for heap leach processing. The highest gold recoveries of over 70% were obtained from the West Ridge oxide composites. Gold recoveries from the Twilight oxide and mixed composites were more variable, but on average were similar to those from the West Ridge oxides. Gold recoveries from the Daylight oxide composites generally were lower, at an average of approximately 62.7% in gold recoveries. The two West Ridge-Deep mixed mineralization composites gave low gold recoveries (<32.0%). Organic (non-carbonate) carbon content was low (0.08% average) and was not correlated to gold recovery.
Gold recoveries obtained from the West Ridge Oxide samples from drill holes DGC789, 790 and 791 ranged from 50.0% to 85.4% and averaged 71.4%. Only 4 of the 28 composites gave gold recoveries below 65%. A single West Ridge-Deep oxide composite (hole DGC796) was tested. Gold recovery from that composite (68.2%) was comparable to the other oxide composites. [The two mixed composites from the same drill hole gave low recoveries.]
Gold recoveries from the Daylight oxide composites averaged 62.7%. The reasons for the variability in gold recovery for this material are not yet understood. The composites that gave low gold recoveries also had relatively low ratios of cyanide soluble gold-to-fire assay ratios (CN/FA). This data indicates that gold recoveries from the low recovery Daylight oxide samples may not be substantially improved by grinding before leaching.
Gold recoveries from the Twilight oxide and mixed composites were similar. Gold recoveries from the Twilight samples ranged from 60.5% to 82.1% and averaged 69.3%.
Reagent consumptions were consistently low and are expected to be low for commercial heap leaching. Cyanide and lime consumption for all tests averaged 0.12 kg/mt and 0.9 kg/mt, respectively.
ABOUT DOBY GEORGE
Doby George is one of the highest-grade, undeveloped open pit heap leach resources in Nevada and one of three mineral deposits on Western Exploration's 100% owned Aura Project. The Aura Project is located 32 kilometers north of the Jerritt Canyon mine, which has been in continual operation since 1981. The deposit is an outcropping, high-grade sediment-hosted mineral deposit, with multiple zones of mineralization identified by drilling in a 1.7 x 0.8 km area (see Figure 7 below). The zone of oxidation extends 150 to 200 meters below surface, while limited deep drilling has encountered unoxidized gold mineralization at depths of over 600 meters below surface. Additional information about the Aura Project is included in the technical report titled "2021 Updated Resource Estimates and Technical Report For the Aura Gold-Silver Project, Elko County, Nevada" dated October 20, 2021 (with an effective date of October 14, 2021) (the "Technical Report").
A copy of the Technical Report is available on SEDAR (www.sedar.com) under Western Exploration's issuer profile.
Homestake Mining Company initially discovered the deposit in the mid-1980s. Since that time, 836 drill holes have been completed, totaling 116,355 meters of drilling. This includes 83 drill holes totaling 23,760 meters that were drilled by Western Exploration LLC between 1998 and 2022. Metallurgical test work completed on oxidized material by Homestake Mining Company, Independence Mining Company, and Atlas Precious Metals Inc., has indicated favorable metallurgy for standard cyanide heap leach processing. Results from the previous metallurgical testing completed on 52 bottle rolls and 23 column leach samples indicate that heap leach gold recoveries approaching seventy percent can be expected via a crush of 1 to 1.5 inches.
In addition to an established mineral resource estimate (as determined in accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101")), the Aura Project has well established infrastructure including year-round accessibility by highway and county-maintained road and nearby access to water and electricity (see Figure 4 below). Western Exploration has exploration, development, and mining rights on 930 hectares of privately owned fee lands through a mineral lease agreement with a local landowner and may purchase those fee lands at any time for the development of Doby George.
The 6,000-hectare Aura Project has identified mineral resources in three different deposits (Doby George, Gravel Creek and Wood Gulch), as supported by the Technical Report (see Table 2 below).
Table 2. Updated mineral resource estimates for the Aura Project (October 21, 2021 Technical Report).
MINERAL RESOURCE ESTIMATE(1)
Au equivalent oz assumes US$1,800 per oz Au and 70:1 ratio of Ag:Au.
Pit constrained 0.2 g/t AuEq cutoff for oxide, 0.4 g/t Au cutoff for mixed and 1.4 g/t Au cutoff for unoxidized.
Pit constrained 0.2 g/t AuEq cutoff.
3.0 g/t Au cutoff.
About Western Exploration
Born from a 25-year history of advancing exploration projects in Nevada as a private company, today Western Exploration is composed of an experienced team of precious metals experts that aims to lead Western Exploration to becoming a premiere gold and silver development company in North America. The Company's principal asset is the 100% owned Aura gold-silver project, located approximately 120 kilometers/75 miles north of the city of Elko, Nevada, and includes three unique gold and silver deposits: Doby George, Gravel Creek, and Wood Gulch. Additional information regarding Western Exploration and the Aura Project can be found on the Company's website and on SEDAR (www.sedar.com) under the Company's issuer profile.
Test Procedure, Sample Preparation, and Quality Assurance
All samples were prepared and analyzed by McClelland Laboratories Inc., Reno, Nevada. Agitated cyanidation bottle roll tests were conducted on a total of 46 drill core composites from the Doby-George deposit to obtain preliminary information regarding heap leach amenability and ore variability. The composites were prepared from eight PQ drill core holes PQ drill holes (DGC-789 through DGC-796). Composites were selected based on drill hole location and depth, sample oxidation, lithology, grade and CN/FA ratio, and each comprised 2.4 – 6.6 meters of continuous drill core. Most (42 of 46) of the composites represented oxide mineralization. Four composites (2 each from West Ridge-Deep and Twilight) represented mixed mineralization.
Direct agitated cyanidation bottle roll tests were conducted on each of the 46 variability composites at an 80%-1.7mm feed size. Bottle roll test ore charges were mixed with water to achieve 40% solids (wt/wt). Natural pulp pHs were measured. Hydrated lime was added to adjust the pH of the pulps to 11.0 before adding the cyanide. Sodium cyanide, equivalent to 1.0 g NaCN/L solution, was added to the alkaline pulps.
Leaching was conducted by rolling the pulps in bottles on the laboratory rolls for 96 hours. Rolling was suspended briefly after 2, 6, 24, 48, and 72 hours to allow the pulps to settle so samples of pregnant solution could be taken for gold and silver analysis by A.A. methods. Pregnant solution volumes were measured and sampled. Free cyanide concentration and pH were determined for each pregnant solution. Make-up water, equivalent to that withdrawn, was added to the pulps. Cyanide concentrations were restored to initial levels. Lime was added, when necessary, to maintain the leaching pH at between 10.8 and 11.2. Rolling was then resumed.
After 96 hours, the pulps were filtered to separate liquids and solids. Final pregnant solution volumes were measured and sampled for gold and silver analysis. Final pH and cyanide concentrations were determined. Leached residues were washed, dried, weighed, and assayed in triplicate to determine residual gold content.
Crushed (2 mm) drill interval samples generated during interval preparation procedures were used for preparation of the variability composites. Select interval samples were combined in entirety or were each blended and split as required to obtain the necessary weight for preparation of footage weighted composites. Each composite was stage crushed to 80%-1.7mm (100%-6.3mm) in size. Each crushed composite was blended and split using a rotary splitter to obtain 1.0 kg for a bottle roll test and triplicate 0.5 kg samples for preparation of head assay pulp samples. The 0.5 kg splits were each pulverized to >95%-106µm and used for generation of head assay pulps. Each composite was assayed in triplicate using conventional fire assay fusion procedures to determine gold and silver content. Each composite was also subjected to a cyanide shake analysis, carbon and sulfur speciation analyses and a multi-element ICP scan.
Qualified Person Approval
The scientific and technical content in this news release has been reviewed and approved by Mark Hawksworth, General Manager of the Aura Project, and a "qualified person" within the meaning of NI 43-101.
For additional information on the Aura Project, please see the Technical Report, which has been prepared in accordance with the requirements of NI 43-101, a copy of which is available on SEDAR (www.sedar.com) under Western Exploration's issuer profile and on Western Exploration's corporate website (www.westernexploration.com).
Cautionary Statements Regarding Estimates of Mineral Resources
This news release uses the terms measured, indicated and inferred mineral resources as a relative measure of the level of confidence in the resource estimate. Readers are cautioned that mineral resources are not mineral reserves and that the economic viability of resources that are not mineral reserves has not been demonstrated. The mineral resource estimate disclosed in this news release may be materially affected by geology, environmental, permitting, legal, title, socio-political, marketing or other relevant issues. The mineral resource estimate is classified in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum's "CIM Definition Standards on Mineral Resources and Mineral Reserves" (CIM) incorporated by reference into NI 43-101. Under NI 43-101, estimates of inferred mineral resources may not form the basis of feasibility or pre-feasibility studies or economic studies except for preliminary economic assessments. Readers are cautioned not to assume that further work on the stated resources will lead to mineral reserves that can be mined economically.
Inferred mineral resources have a great amount of uncertainty as to their existence and as to whether they can be mined legally or economically. On October 31, 2018, the SEC adopted new mining disclosure rules ("S-K 1300") that are more closely aligned with current industry and global regulatory practices and standards, including NI 43-101, although there are some differences in the two standards. Accordingly, information concerning mineral deposits contain in this release may not be comparable with information made public by U.S. companies that report in accordance with S-K 1300.
Cautionary Note Regarding Forward-Looking Information
This news release may contain "forward-looking information" and "forward-looking statements" within the meaning of the applicable Canadian and United States securities legislation (collectively, "forward-looking statements"). These forward-looking statements, by their nature, require the Company to make certain assumptions and involve known and unknown risks and uncertainties that could cause actual results to differ materially from those expressed or implied in such forward-looking statements. Any statement that involves predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often, but not always, using phrases such as "expects", or "does not expect", "is expected", "interpreted", "management's view", "anticipates" or "does not anticipate", "plans", "budget", "scheduled", "forecasts", "estimates", "potential", "feasibility", "believes" or "intends" or variations of such words and phrases or stating that certain actions, events or results "may" or "could", "would", "might" or "will" be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This news release contains the forward-looking information pertaining to, among other things: the focus and results of the bottle roll test program; the accuracy of results from prior exploration activities conducted at the Aura Project; the key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in this news release; the prospects, if any, of the Doby George, Wood Gulch and Gravel Creek mineral deposits; future drilling at the Aura Project; the significance of historic exploration activities and results; and the ability to expand the existing mineral resources at the Aura Project. Such factors include, among others, risks relating to the ability of exploration activities (including drill results) to accurately predict mineralization; errors in management's geological modelling; the ability of Western Exploration to complete further exploration activities, including drilling; property and royalty interests in respect of the Aura Project; the ability of the Company to obtain required approvals; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, Western Exploration cannot assure shareholders and prospective purchasers of securities of the Company that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Western Exploration nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. Western Exploration does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.
For additional information with respect to these and other factors and assumptions underlying the forward‐looking statements and forward-looking information made in this news release concerning Western Exploration, see the management information circular dated November 12, 2021, available electronically under Western Exploration's issuer profile on SEDAR (www.sedar.com). The forward-looking statements set forth herein concerning Western Exploration reflect management's expectations as at the date of this news release and are subject to change after such date. Western Exploration disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, other than as required by law.
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. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.
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