Exploration success continues beyond the May 2, 2023 resource estimate

Vancouver, June 13, 2023 – Prime Mining Corp. (“Prime” or the “Company”) (TSX-V: PRYM, OTCQX: PRMNF, Frankfurt: 04V3) is pleased to announce the filing of a technical report for the updated mineral resource estimate (“MRE”), reported on May 2, 2023, for its Los Reyes gold-silver project located in Sinaloa State, Mexico.  The report, dated June 12, 2023, is titled “​​The Los Reyes Project, México” (the “2023 Technical Report”).

The 2023 Technical Report was prepared under the supervision of Mr. John Sims, CPG.  Mr. Sims is President of Sims Resources LLC and is an “Independent Qualified Person” in accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”). The 2023 Technical Report supersedes the technical report on the Los Reyes Project dated April 2, 2020.

The 2023 Technical Report can be found on the Company’s website at and on SEDAR at, under the Company’s Issuer Profile.

Resource Highlights:

  • The addition of 100,000 metres (“m”) of Prime drilling has doubled the current MRE compared to the April 2020 resource, with a discovery cost of approximately US$25 per gold equivalent1 (“AuEq”) ounce (“oz”).
  • At the resource gold cut-off grade of 0.22 gpt, Prime’s updated open pit MRE (Table 1) contains:
    • 1.47 million Indicated AuEq ounces at a 1.68 grams per tonne (“gpt”) average grade. This represents a 73% increase in Measured and Indicated AuEq ounces, and 26% increase in AuEq grade.  This is 1.0 million ounces of gold at 1.16 gpt and 35 million ounces of silver at 40.4 gpt.
    • 0.73 million Inferred AuEq ounces at a 1.26 gpt average grade. This represents a 175% increase in AuEq ounces and 8% increase in AuEq grade. This is 0.5 million ounces of gold at 0.85 gpt and 18.4 million ounces of silver at 31.5 gpt.
  • Using a higher 1.00 gpt gold cut-off grade, the MRE highlights a robust, higher-grade open pit resource that contains in excess of 1.0 million AuEq Indicated ounces at an average AuEq grade of 3.70 gpt (see Table 2 for more details).
  • The MRE has a high-grade open pit mill resource and a lower grade heap leach portion.
  • The MRE includes drilling completed before December 31, 2022 from only the three main zones at Los Reyes: Guadalupe, Z-T and Central.
  • This MRE does not include positive results from:
    • Mariposa, Las Primas and Fresnillo;
    • highly prospective exploration targets outlined in Prime’s February 27th news release;
    • over 34,000 m drilled to-date during 2023.
  • With ongoing drilling success, the Company believes there is significant potential to expand the MRE.

Drilling is ongoing in the three known main deposit areas (Guadalupe, Central and Z-T) that are larger than previously reported. Potential also exists for new discoveries where mineralized trends have been identified outside of the currently defined resource areas.

New multiple wide, high-grade intercepts in Z-T area

Following the May 2 resource update news release, Prime reported on May 24, 2023 the results from fourteen new core holes drilled at the southeast end of the Z-T Area, which were all outside of the resource pit shell (link to press release here).  These results confirm the potential ongoing expansion of gold-silver resources in addition to and not included in the Company’s MRE and follows similar Z-T results released January 11, 2023. Recent results from Z-T drilling are expected to be reported in the coming weeks.

Next Steps

Prime is advancing its 60,000 m exploration drilling program at Los Reyes in 2023. The Company is drilling the highly prospective Guadalupe, Z-T and Central Zones in order to expand known resources in these areas and is further exploring newly developing resource areas.  Prime has approximately $45.5 million in its treasury (as reported in Q1 2023 financial results news release) and remains prudent in exploration expenditures by utilizing a success-based approach to the drill program planning. Work will also continue on other technical areas including metallurgical test work, geotechnical assessments, mine and processing stream optimization and trade-offs, environmental studies and social contributions.

Table 1 – 2023 Resource Estimate at 0.22 gpt Gold Cut-off Grade
($1700/oz gold price, $22/oz silver price, economic pit-constrained estimate)2

Process Stream Assurance Category Ore


Average Gold Grade Contained Gold Average Silver Grade Contained Silver Average


Contained AuEq
  (millions) (gpt) (k ozs) (gpt) (k ozs) Grade (gpt) (k ozs)
Mill Measured (M)           –            –            –            –            –            –            –
Indicated (I)       16.6 1.66         888 60.2    32,182 2.44      1,304
  M+I       16.6 1.66         888 60.2    32,182 2.44      1,304
Inferred       10.8 1.18         411 47.2    16,390 1.79         623
Heap Measured (M)           –            –            –            –            –            –            –
Leach Indicated (I)       10.5 0.37         125 9.1      3,081 0.49         165
  M+I       10.5 0.37         125 9.1      3,081 0.49         165
Inferred         7.3 0.37           86 8.3      1,944 0.47         111
TOTAL Measured (M)           –            –            –            –            –            –            –
Indicated (I)       27.2 1.16      1,013 40.4    35,263 1.68      1,470
  M+I       27.2 1.16      1,013 40.4    35,263 1.68      1,470
Inferred       18.1 0.85         497 31.5    18,334 1.26         734


Resource Description

The Los Reyes resource is composed of three main areas: Guadalupe, Z-T and Central (see Figure 1 – Resource Area Map).  Resources were estimated assuming a gold price of $1700 and silver price of $22, and various processing, operating cost and other economic parameters as described in Note 2 below.  Resources are reported from blocks within an economically constrained pit, containing gold grades greater than 0.22 gpt. The resource areas remain open along strike and at depth (see Figure 2 – Resource Area 3D view).

The majority of the Los Reyes resource is contained within a high-grade envelope (see Figure 3 – Guadalupe East cross-section).  For example, at a 1.0 gpt gold cut-off, the Los Reyes MRE contains in excess of 1 million gold equivalent ounces at an average grade of 3.70 gpt AuEq in the Indicated category and 374,000 ounces at a grade of 3.07 gpt AuEq in the Inferred category (see Table 2).

Table 2 – 2023 Resource Sensitivity Estimate at 1.0 gpt Gold Cut-off Grade
($1700/oz gold price, $22/oz silver price, economic pit-constrained estimate)2

  Assurance Category Ore


Average Gold Grade Contained Gold Average Silver Grade Contained Silver Average


Contained AuEq
  (millions) (gpt) (k ozs) (gpt) (k ozs) Grade (gpt) (k ozs)
1.00 g/T Measured (M)                 –               –            –               –                –
Cutoff Indicated (I)              8.8 2.59         731 85.6    24,212 3.70          1,045
  M+I              8.8 2.59        731 85.6   24,212 3.70          1,045
Inferred              3.8 2.30         281 59.2      7,208 3.07             374

For the purposes of this MRE, all resources are assumed to be mined using conventional open pit methods (see Note 2 for further assumptions).

The MRE was estimated using a drilling cut-off date of December 31, 2022.  It is based on a resource block model developed from almost 50,000 metres (”m”) of drilling completed by previous property owners, and over 100,000 m of drilling completed by Prime, of which more than 90% is diamond drill core.

The following information is available on our website, including the full drill hole table up to December 31, 2022:

Link 1 PDF Figures

Link 2 – PDF Drill Hole Table


Figure 1 – Resource Area Pits, and Generative Target Locations


Figure 2 –Northeast View of Resource Area Indicating Expansion Potential


  1. Gold equivalent grades are calculated as in-situ contained grades, applying the assumed ratio of gold to silver prices using the following formula: AuEq grade (gpt) = Gold grade (gpt) + Silver grade (gpt) x ($22 / $1,700). Relative recoveries are not considered in the in-situ contained grade estimate but are stated below and utilized in the resource shell economic pit constraints. All dollar values are in US dollars unless otherwise stated.
  2. Resource estimate is based on economically constrained pits using the following optimization parameters (all dollar values are in US dollars):
    • $1,700/ounce gold price and $22/ounce silver price
    • Mill recoveries of 93% and 83% for gold and silver, respectively
    • Heap leach recoveries of 73% and 25% for gold and silver, respectively
    • 45-degree pit slopes, with an assumed 5% ore loss and 5% dilution factor applied to the 5x5x5m resource block model
    • Mining costs of $2.00 per tonne of waste mined and $2.50 per tonne of ore mined
    • Milling costs of $15 per tonne processed and heap leaching costs of $4 per tonne processed
    • G&A of $1.60 per tonne processed
    • 3% royalty costs and 1% selling costs were also applied
    • Unless otherwise noted, an overall 0.22 g/T gold cut-off was applied to all ore blocks

Advisory Payment

The Company also announces that, subject to approval of the TSX Venture Exchange, it will issue 63,025 units (each, an “Advisory Unit”) at a deemed price of $1.785 per Advisory Unit, to an arms-length advisor, in payment of a fee of $112,500 owing in connection with a services agreement renewed by the Company on June 8, 2022.  Each Advisory Unit consists of one Common Share and one share purchase warrant exercisable at a price of $2.52 until June 8, 2026.  The Advisory Units are subject to a statutory hold period in accordance with applicable Canadian securities law for a period of four-months-and-one-day following issuance.

QA/QC Protocols and Sampling Procedures

Drill core at the Los Reyes project is drilled in predominately HQ size (63.5 millimetre “mm”), reducing to NQ size (47.6 mm) when required. Drill core samples are generally 1.50 m long along the core axis with allowance for shorter or longer intervals if required to suit geological constraints. After logging intervals are identified to be sampled and split, and one half is submitted for assay. RC drilling returns rock chips and fines from a 133.35 mm diameter tricone bit. The returns are homogenized and split into two halves, with one half submitted for analysis and the other half stored.

Sample QA/QC measures include unmarked certified reference materials and blanks as well as preparation duplicates are inserted into the sample sequence and make up approximately 8% of the samples submitted to the laboratory for each drill hole.

Samples are picked up from the Project by the laboratory personnel and transported to their facilities in Durango or Hermosillo Mexico, for sample preparation. Sample analysis is carried out by Bureau Veritas and ALS Labs, with fire assay, including over limits fire assay re-analysis, completed at their respective Hermosillo, Mexico laboratories and multi-element analysis completed in North Vancouver, Canada. Drill core sample preparation includes fine crushing of the sample to at least 70% passing less than 2 mm, sample splitting using a riffle splitter, and pulverizing a 250-gram split to at least 85% passing 75 microns.

Gold in diamond drill core is analyzed by fire assay and atomic absorption spectroscopy of a 30 g sample (code FA430 or Au-AA23). Multi-element chemistry is analyzed by 4-Acid digestion of a 0.25-gram sample split (code MA300 or ME-ICP61) with detection by inductively coupled plasma emission spectrometer for a full suite of elements.

Gold assay techniques FA430 and Au-AA23 have an upper detection limit of 10 ppm. Any sample that produces an over-limit gold value via the initial assay technique is sent for gravimetric finish via method FA-530 or Au-GRA21. Silver analyses by MA300 and ME-ICP61 have an upper limit of 200 ppm and 100 ppm, respectively. Samples with over-limit silver values are re-analyzed by fire assay with gravimetric finish FA530 or Au-GRA21.

Both Bureau Veritas and ALS Labs are ISO/IEC accredited assay laboratories. Drill core assay results range from below detection to 200.00 gpt gold and 4,955.0 gpt silver.

Qualified Person

John Sims, CPG, is a qualified person for the purposes of National Instrument 43-101 and has reviewed and approved the technical content in this news release pertaining to the MRE.

Scott Smith, P.Geo., Executive Vice President of Exploration, is a qualified person for the purposes of National Instrument 43-101 and has reviewed and approved the technical content in this news release pertaining to the exploration results.

Additional Notes

Prime’s mineral resource estimate as of May 2, 2023 is classified in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) “CIM Definition Standards – For Mineral Resources and Mineral Reserves” adopted by the CIM Council (as amended, the “CIM Definition Standards”) and in accordance with the requirements of National Instrument 43-101 “Standards of Disclosure for Mineral Projects”. Mineral resources are not reserves and do not have demonstrated economic viability.

About the Los Reyes Gold and Silver Project

Los Reyes is a rapidly evolving high-grade, low sulphidation epithermal gold-silver project located in Sinaloa State, Mexico. Historic operating results indicate that an estimated 1 million ounces of gold and 60 million ounces of silver were recovered from five separate operations at Los Reyes between 1770 and 1990. Prior to Prime’s acquisition, recent operators of Los Reyes had spent approximately US$20 million on exploration, engineering, and prefeasibility studies. The Project remains underexplored and holds potential for additional discovery and resource expansion.

Since acquiring Los Reyes in 2019, Prime has spent approximately US$30 million on direct exploration activities and has completed two phases of comprehensive drilling totaling over 100,000 metres.  Results to date suggest the three known main deposit areas, Guadalupe, Central and Z-T, are larger than previously reported. Potential also exists for new discoveries outside of the currently defined resource areas.

About Prime Mining

Prime is managed by an ideal mix of successful mining executives, strong capital markets personnel and experienced local operators all focused on unlocking the full potential of the Los Reyes Project. The company has a well-planned capital structure with a strong management team and insider ownership.


Daniel Kunz

Chief Executive Officer

For further information, please contact:

Daniel Kunz

Chief Executive Officer and Director
Prime Mining Corp.
1307 S. Colorado Ave.
Boise, Idaho 83706
Telephone: +1 (208) 926-6379 office

Scott Hicks

Executive Vice President
Prime Mining Corp.
710 – 1030 West Georgia Street
Vancouver, BC, V6E 2Y3
Telephone: +1 (604) 428-6128 office

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Forward Looking Information

This news release contains certain “forward-looking information” and “forward-looking statements” within the meaning of Canadian securities legislation as may be amended from time to time, including, without limitation, statements regarding the perceived merit of the Company’s properties, including additional exploration potential of Los Reyes, potential quantity and/or grade of minerals, the potential size of the mineralized zone, metallurgical recoveries, and the Company’s exploration and development plans in Mexico. 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 several risks and uncertainties. Certain material assumptions regarding such forward-looking statements were made, including without limitation, assumptions regarding the price of gold, silver and copper; the accuracy of mineral resource estimations; that there will be no material adverse change affecting the Company or its properties; that all required approvals will be obtained, including concession renewals and permitting; that political and legal developments will be consistent with current expectations; that currency and exchange rates will be consistent with current levels; 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 mineral resource estimates, including but not limited to changes to the cost assumptions, variations in quantity of mineralized material, grade or recovery rates, changes to geotechnical or hydrogeological considerations, failure of plant, equipment or processes, changes to availability of power or the power rates, ability to maintain social license, changes to interest or tax rates, changes in project parameters, delays and costs inherent to consulting and accommodating rights of local communities, environmental risks, title risks, including concession renewal, commodity price and exchange rate fluctuations, risks relating to COVID-19, delays in or failure to receive access agreements or amended permits, risks inherent in the estimation of mineral resources; and risks associated with executing the Company’s objectives and strategies, including costs and expenses, as well as those risk factors discussed in the Company’s most recently filed management’s discussion and analysis, as well as its annual information form dated April 22, 2022, available on 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.


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