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Kore Mining Announces Results from PEA – US$ 263M NPV5% with IRR of 40% Using US $1,600 Gold at Long Valley Gold Deposit

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Kore Mining Announces Results from PEA – US$ 263M NPV5% with IRR of 40% Using US $1,600 Gold at Long Valley Gold Deposit






KORE Mining Ltd. (TSX-V: KORE) (OTCQX: KOREF) is pleased to announce a positive Preliminary Economic Assessment for the Company’s 100% owned Long Valley Gold Deposit located in California, USA. The PEA demonstrates Long Valley’s potential to generate strong economic returns while being in full compliance with California’s stringent operating and reclamation standards.  Long Valley has clear upside potential from targets on-strike and lateral to the current modelled oxide mineralization and KORE intends to aggressively explore this untapped potential.





  • Robust economics: US$ 263 million NPV5%post-tax with 40% IRR at US$ 1,600 per ounce gold
  • 100,000 ounces gold per year over 7 years at AISC of US$ 732 per ounce
  • Technically simple: shallow open pit, heap leach with nearby infrastructure
  • Significant leverage to gold: US$ 396 million NPV5%at recent spot US$ 1,900 per ounce gold
  • Unmodelled silver potential from metallurgical test-work
  • Shallow oxide and sulphide feeder exploration potential to further enhance project


Watch a video (50 seconds) of Scott Trebilcock, KORE’s CEO, summarizing the highlights of the Long Valley PEA – click here. Refer to the Long Valley PEA Summary infographic in Figure 1



KORE’s CEO Scott Trebilcock stated:


“The Long Valley PEA generated an NPV5% of US$ 396 million at US$ 1,900 per ounce gold.  In addition, KORE has a preliminary economic assessment on its Imperial Project, published on May 19, 2020, which generated an NPV5% of US$ 660 million at US$ 1,900 per ounce gold.  KORE has the unique advantage of having two simple, low-cost heap leach development projects in one Company and can manage capital needs for growth, permitting and construction to maximize shareholder value.”



Mr. Trebilcock continued, ” The Long Valley PEA is a key milestone towards KORE’s becoming a significant North American producer envisioning production of 250,000 ounces of gold a year from our US projects.”



KORE’s COO Marc Leduc added: “The mine plan at Long Valley complies with California’s stringent reclamation and environmental laws while delivering skilled jobs and long-term regional economic development. KORE’s next step is to grow Long Valley by drilling oxide and sulphide targets while further defining silver potential.”



The PEA is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves.  There is no certainty that the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.





The PEA was prepared in accordance with National Instrument 43-101 by Global Resource Engineering (Denver) – Terre Lane, RMSME MMSAQP, Todd Harvey, PhD, RMSME in conjunction with a revised resource estimate prepared by Mine Development Associates and authored by Neil Prenn, PE.  The team was led by Marc Leduc, P.Eng. the COO of KORE Mining. The Company plans to file the PEA on SEDAR at within 45 days in accordance with NI 43-101.



This news release contains information from a preliminary economic assessment, which is a conceptual study, and other forward-looking information about potential future results and events. Please refer to the cautionary statements in the footnotes below and the Cautionary Statements located at the end of this news release, which include associated assumptions, risks, uncertainties and other factors.



Unless otherwise stated, all dollar figures are in United States dollars (“$”) and masses are in short tons.




Economics Pre-Tax Post-Tax
Net present value (NPV5%) at 0.75C$/US$ C$ millions $479 $351
Net present value (NPV5%) US$ millions $359 $263
Internal rate of return (IRR) % 48% 40%
Payback (undiscounted) Years 2.0 2.3
LOM avg. annual cash flow after tax & capital US$ millions $95 $78
LOM cumulative cash flow (undiscounted) US$ millions $503 $384
Gold price assumption US$ per ounce $1,600
Mine life Years 7
Average annual mining rate  million tons/yr 18.5
Average annual gold production thousand ounces/yr 100
Total LOM recovered gold thousand ounces 717
Initial capital costs US$ millions $158



Life-of-mine calculation and “Mine Life” is defined as the duration of mining operations, 7 years.  There are additional years of site work for residual leaching, washing, back-filling and reclamation modelled.






The following table demonstrates the post-tax sensitivities of NPV and IRR to gold price per ounce. The base case, highlighted in the table below, assumes US$1,600 per ounce of gold:



Economic Sensitivities to Gold Prices (post-tax)
Per ounce of gold (NPV5%) millions IRR%
US$1,200 US$ 86 19%
US$1,400 US$ 174 30%
US$1,600 US$ 263 40%
US$1,800 US$ 351 49%
US$2,000 US$ 440 57%
US$2,200 US$ 527 65%





The PEA outlined a number of initiatives that may enhance the Project including:


  • Assaying silver in all future drill programs to add silver into the resources;
  • Conducting metallurgical tests to establish optimal crush size and cement addition;
  • Performing test work on very low-grade samples to determine viability of run-of-mine leaching;
  • Reviewing contract mining to reduce initial capital; and
  • Drilling for more oxide resources and deep sulfides to look for high-grade feeder zones.




This PEA demonstrates the robust nature of the current Long Valley mineralization.  However, there is a clear opportunity to grow shallow oxide mineralization as the mineralization remains open in all directions and on a separate parallel structure. Additional mineralization could extend mine life, reduce capital intensity and generate higher project economic returns.  A summary of oxide expansion targets is included in Figure 2.



Additionally, as a fully intact epithermal deposit with a large at surface footprint, Long Valley has the potential for high-grade sulphides in the underlying feeder structures.  Discovering high-grade sulphides would open up additional development pathways for the Project, such as underground mining and milling of mineralization.  A summary of sulphide expansion targets is included in Figure 3.



KORE plans to drill-test the highest priority oxide and sulphide targets.  KORE is currently permitting drill pads with our regulator the US Forest Service. Drilling is planned for H1 2021, subject to USFS permitting timelines.



Details of the Long Valley exploration targets are in KORE news releases dated January 30, 2020 and March 24, 2020





GRE notes that the Long Valley Project has an abundance of drill data as a result of the exploration completed in the 1980s and 1990s.  The Project also has metallurgical sampling and testing from previous owners, reviewed by GRE, to support the initial engineering design.  This data will act as an important background and aid in the design of future work on the project.





The PEA presents an open-pit, heap leach scenario where oxide, transition and sulphide ore is stacked on the leach pads by conveyors after two stages of crushing and agglomeration.   The conveyor system is also used at the end of the mine life to backfill the final pits and reclaim the site to California’s stringent standards. In the design process, the engineering team also looked at several other scenarios:


  • Silver production; a Merrill- Crowe precious metal recovery circuit is included in the project design to recover both gold and silver. Silver is NOT quantified in the resource or PEA as it was not assayed regularly in historic drilling but was seen in all of the previous metallurgical test work.
  • Smaller, oxide only mine plan that had lower stripping ratio, lower capital and operating costs but yielded less ounces. KORE ultimately selected the mine plan with the most ounces recovered as those ounces would likely be mined at current metal prices.


Mining Plan and Processing Summary
Mine life years 7
Mining rate average tons per day 50,600
Strip ratio waste: mineralization 1.4
Total tonnage mined million tons 130.7
Total mineralized material mined million tons 54.2
Heap leach stacking rate average tons per day 21,100
Average LOM grade gram per metric tonne 0.671
Average LOM recovery % 68%



A detailed mine plan by year is included in Table 1 at the end of this news release.






Mining costs for owner operated mining, processing and other costs were developed from a mix of first-principle engineering and benchmarked to the many ROM heap leach operations in California and nearby Nevada.  The Long Valley Project is located near a large skilled labour pool and has local access to road and power infrastructure. The Project has several options for water locally with potential surface and ground water sources.



Operating Costs (LOM average) (1)
Mining costs (per ton mined) US$/st mined $1.78
Mining costs US$/st processed $4.29
Processing costs US$/st processed $2.64
G&A costs US$/st processed $0.69
Total site operating costs US$/st processed $7.62
Cash Costs*
Cash costs (LOM)* US$/oz $612
(1)     Not including post-production reclamation and backfilling.  See LOM description above.


The assumed truck diesel fuel price in the PEA is US$ 2.00 per US gallon.  About 11% of the mining cost is fuel so lower fuel prices would decrease mining costs moderately.





Initial capital costs in the PEA are US$ 158 million including a 25% contingency of US$ 31.6 million. Infrastructure costs are low due to the proximity of road, water and power infrastructure. Initial capital also assumes KORE is the owner-operator of all equipment. Further enhancements may be possible with contract mining. Sustaining capital is mainly for heap leach pad expansion and additional mining equipment.



Pre-Production and Sustaining Capital Costs (US$ millions)
Mining and mine infrastructure $40.6
Heap leach pads and plant $55.5
Infrastructure and G&A $16.8
Working capital $4.4
Contingency (25%) $27.1
Pre-production mining $13.7
Total Pre-Production Cost $158.0
LOM sustaining capital $18.4
Closure incl. backfill (1) $67.5
(1)     Closure cost includes final backfilling of the open pit and site reclamation to California’s stringent standards.  The cost includes US$38.7 million in mining cost, US$13.5 million in site operating G&A during back-filling of the final pit, in addition to US$15.3 million in other site closure costs.  Backfill will return the site to plus 25 feet of original topography while re-establishing drainages.  The balance of the closure cost is for normal non-backfill site closure costs to remediate disturbances, remove structures, etc.





All-in-sustaining costs are competitive with peer projects and in the second quartile when compared to the World Gold Council AISC cost metric.  Long Valley’s AISC* is built up as follows:



AISC* per ounce (US$ millions)
Operating cost (1) $580
Royalties (2) $32
Sustaining capital $26
Closure $94
Total AISC* $732
(1)     Operating costs includes US$5 per ounce offsite refining. 
(2)     Royalties consist of: (a) 1% NSR royalty to Royal Gold; and (b) 1% NSR royalty to Vista Gold. 





Long Valley is well drilled with a total of 896 holes, the majority being completed by reverse circulation with lesser core, rotary and air track from 1988-1996.  The mineral resource model, as presented within KORE’s December 18, 2019 Technical Report, has been updated using a more detailed geologic model which has allowed for the assigning of lithology-specific density values. In addition, the reported resource estimate has been updated using revised optimization parameters for the constraining pit shell. The updated estimate, effective September 15, 2020, was prepared by Mine Development Associates and the resource block model derived by Mine Development Associates was used in the development of this PEA.  The current Mineral Resources are shown in Imperial and Metric units in the tables below.  The revised pit-shell parameters, including the use of a higher gold price, US$ 1,800 per ounce, are within the table footnotes.



Long Valley Mineral Resource Estimate – Imperial Units (as at September 15, 2020)



Classification Cut-Off

(oz / ton)


(‘000 tons)

Grade Gold

(oz / ton)

Gold (‘000 oz)
Oxide 0.005 35,276 0.018 635
Transition 0.006 4,026 0.014 56
Sulphide 0.006 30,914 0.017 526
Total Indicated   70,216 0.017 1,217
Oxide 0.005 8,997 0.020 180
Transition 0.006 1,277 0.016 20
Sulphide 0.006 14,033 0.018 253
Total Inferred   24,307 0.019 456



Long Valley Mineral Resource Estimate – Metric Units (as at September 15, 2020)



Classification Cut-Off

(g / tonne)


(‘000 tonnes)

Grade Gold

(g / tonne)

Gold (‘000 oz)
Oxide 0.17 32,002 0.62 635
Transition 0.21 3,653 0.48 56
Sulphide 0.21 28,045 0.58 526
Total Indicated   63,699 0.58 1,217
Oxide 0.17 8,162 0.69 180
Transition 0.21 1,159 0.55 20
Sulphide 0.21 12,731 0.62 253
Total Inferred   22,052 0.65 456


  • Numbers may not add or multiply accurately due to rounding.
  • Mineral Resources do not have demonstrated economic viability.
  • CIM Definition and Standards were followed for the Mineral Resource estimates.
  • The Mineral Resource estimate was prepared by Neil Prenn P.E., who is an independent consultant and Qualified Person for the purpose of NI 43-101.
  • Mineral Resources are reported at a 0.005oz Au/ton cut-off grade for oxide material to be processed using heap leach methods and 0.006oz Au/ton cut-off grade for transition and sulfide material to be processed by milling methods.
  • Mineral Resources are contained within a US$1,800 per ounce optimized pit. Other pit optimization parameters are:
    • Pit Slope: 45 degrees
    • Mining: US$1.80 / ton mined
    • Crushing: US$1.40 / ton processed
    • Heap Leach: US$1.80 / ton processed
    • Sulfide Mill: US$10.0 / ton processed
    • G&A: US$0.70 / ton processed
    • Refining: US$5 / oz Au produced
    • Recovery (Oxide): 80% heap recovery
    • Recovery (Transition): 90% mill recovery



The Preliminary Economic Assessment was prepared by GRE with Terre Lane, PE being the Qualified Person in charge of its preparation and who is independent of KORE.  The mineral resource portion of the PEA was prepared by Neil Prenn, P.E. of Mine Development Associates and who is independent of KORE.  With regards to technical matters in this press release Marc Leduc, P.Eng. is the Qualified Person within the meaning of NI 43-101 and has reviewed and validated that the information in this press release is consistent with that provided by the Qualified Persons responsible for the PEA.



Further information about the PEA referenced in this news release, including information in respect of data verification, key assumptions, parameters, risks and other factors, can be found in the NI 43-101 technical report for the Long Valley Gold Deposit that the Company intends to file on SEDAR ( under KORE’s profile and on the Company’s website ( within the next 45 days from the date of this news release.





Items marked with a * in this news release are alternative performance measures. Alternative performance measures are furnished to provide additional information. These non-IFRS performance measures are included in this news release because the Company believes these statistics are key performance measures that provide investors, analysts and other stakeholders with additional information to understand the costs associated with the Project. These performance measures do not have a standard meaning within IFRS and, therefore, amounts presented may not be comparable to similar data presented by other mining companies. These performance measures should not be considered in isolation as a substitute for measures of performance in accordance with IFRS.



“Cash Costs ” and “Cash Costs” are a non-IFRS measure reported by KORE on an ounces of gold sold basis.  Cash costs include mining, processing, refining, general and administration costs and royalties but excludes depreciation, reclamation, income taxes, capital and exploration costs for the life of the mine, defined above as 7 years.



“All-In-Sustaining-Costs” is a non-IFRS measure reported by KORE on a per ounce of gold sold basis that includes all cash costs noted above (mining, processing refining, general and administration and royalties), as well as sustaining capital and closure costs, but excludes depreciation, capital costs and income taxes.





Long Valley is 100% owned epithermal gold project located in Mono County California. The Long Valley deposit is an intact epithermal gold deposit with a large 2.5 by 2 kilometer oxide gold footprint. 


The Long Valley deposit is an intact low sulphidation epithermal gold/silver deposit, hosted within a melange of fine to coarse volcanogenic sedimentary lithologies.  Mineralization at Long Valley has developed due to a combination of deep-rooted fault structures and a resurgence of rhyolite within an active caldera.  The Hilton Creek Fault structure transects and served as a fluid conduit for interaction with the underlying hydrothermal system, while the rhyolite resurgence caused brittle fracturing of sediments and created voids or traps for mineralization and gold deposition.  The combination of these factors yields strongly altered kaolin and quartz-hematite zones that are the primary host for gold mineralization. 



The Hilton Creek Fault remains underexplored on-strike north and south and several parallel structures have been defined using geophysics, the eastern one hosting some of the current mineral resource and the western one being unexplored.  Long Valley is therefore open to new oxide discoveries in all directions.  More details on the deposit geology and exploration potential can be found in KORE’s January 30, 2020 and March 24, 2020 news releases. 





KORE is 100% owner of a portfolio of advanced gold exploration and development assets in California and British Columbia.  KORE is supported by strategic investor Eric Sprott who recently invested $7.0 million, bringing his total ownership to 26%.  KORE management and Board are aligned with shareholders, owning and additional 38% of the basic shares outstanding.  KORE is actively developing its Imperial Gold project and is aggressively exploring across its portfolio of assets.


Posted September 15, 2020

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