Diablillos

 

Diablillos is a 7,919 ha (79 km2) property located in the Argentine Puna region, which is the southern extension of the Altiplano of southern Peru, Bolivia, and northern Chile. It is a high plateau, separating the Cordillera Oriental to the east from the Andean Cordillera (Cordillera Occidental) to the west. 

There are currently multiple near-surface deposits on the Diablillos property, including Oculto, JAC, Fantasma and Laderas.  Diablillos is a high-sulphidation epithermal silver-gold deposit derived from remnant hot springs activity following Tertiary-age local magmatic and volcanic activity with strong supergene overprinting.

Ownership 100% AbraSilver
Remaining payment of US$7M due to EMX Royalties by July 31, 2025
Geology High-sulphidation epithermal silver-gold deposit
Location Salta Province, Argentina
Approx. 160 km southwest of city of Salta, along border between Provinces of Salta and Catamarca
Elevation Between 4,100 to 4,650 MASL
Nearby Projects in Salta Lindero (Fortuna Silver)
Taca Taca (First Quantum)
El Quevar (Golden Minerals)
Drilling to Date +130,000m with expenditures of +US$55 million
Stage Pre-Feasibility Study completed on March 25, 2024,  with US$494 Million After-Tax NPV and 26% IRR
 

All dollar ($) figures are presented in US dollars unless otherwise stated. Base case metal prices used in this analysis are $1,850 per gold (“Au”) ounce (“oz”) and $23.50 per silver (“Ag”) oz.

PFS Study Highlights:

  • Attractive project economics – $494 million after-tax Net Present Value discounted at 5% per annum (“NPV5%”), at base-case metal prices, with an after-tax Internal Rate of Return (“IRR”) of 25.6% and payback of 2.4 years.  At current spot prices1 an after-tax NPV5% of $661 million with an IRR of 30.3% and payback of 2.1 years
  • Substantial silver and gold production – 13.3 Moz silver-equivalent (“AgEq”) average annual production over a 13-year life-of-mine (“LOM”), comprised of 7.7 Moz Ag and 71 koz Au, or, with average annual production of 17.9 Moz AgEq over the first five years of full mine production, comprised of 14.5 Moz Ag and 44 koz Au
  • Low All-in Sustaining Cash Costs (“AISC”)2 Average AISC of $12.40/oz AgEq over LOM
  • Low capital cost – Initial pre-production capital expenditure of $373 million and sustaining capital of $65 million
  • Open pit mine with high grades – Conventional open pit mining and processing plant focused exclusively on oxide mineralization with average grades of 91 g/t Ag and 0.81 g/t Au (155 AgEq) over the LOM
  • Maiden Proven & Probable (“P&P”) Mineral Reserves Based on the PFS, Diablillos is estimated to hold P&P Minerals Reserves containing 210 Moz of AgEq metal (42.3 Mt at 91 g/t Ag & 0.81 g/t Au)
  • Potential for additional economic improvements – Several opportunities have been identified that may significantly enhance the economic returns as detailed later in this release:
    • A preliminary internal study estimates that a significant amount of mineralized material below cut-off grade, which is treated as waste in the PFS, could be amenable to heap leaching or other low-cost processing technologies, with further study work expected to be completed by mid-2024.
    • A Phase IV drill campaign is planned to further expand the Mineral Resource and Reserve estimates within the existing deposits and to define new adjacent mineralized zones through step-out drilling.

Project Economics

Table 1 – Commodity Price Sensitivity Analysis

Economic Parameters Base Case Prices Spot Prices1 Base Case Prices
+15%
Base Case Price
-15%
2021 PEA Price Deck
Silver Price ($/oz) $23.50 $24.76 $27.03 $19.98 $24.00
Gold Price ($/oz) $1,850 $2,181 $2,128 $1,573 $1,650
After-tax NPV (5%, US$ million) $493.7 $661.5 $741.9 $245.6 $447.3
After-tax NPV (8%, US$ million) $363.4 $498.5 $567.7 $159.0 $328.2
After-Tax IRR (%) 25.6% 30.3% 33.3% 16.7% 24.6%
Payback (years) 2.4 2.1 2.1 3.2 2.4

1Note:  Spot Price as at close on March 21, 2024, per Reuters.com 

The PFS presents a range of metal pricing scenarios on an after-tax basis to evaluate the economics of both upside and downside price scenarios. The economics of the Diablillos project are very robust and offer significant leverage to both silver and gold prices, with an after-tax NPV5% of $742 Million (+50%) if prices rise 15% from the Base Case (Table 1).

Production Summary

The Diablillos project is envisioned as a conventional open pit operation over a mine life of approximately 13.5 years of production with mill throughput of 9,000 tonnes per day. Total material moved (excluding stockpile rehandle and commissioning) is 313.5 Mt (42.3 Mt mineralization and 271.2 Mt waste) at a strip ratio of 6.4 (excluding pre-stripping).

The proposed operation consists of a common open pit that will extract both the Oculto and JAC deposits, the mineralization of which are connected by a narrow node. The JAC deposit contains higher silver grade ore that occurs near-surface and, consequently, will be mined and processed in the earlier years of the mine plan.  Additionally, the overburden at JAC provides suitable construction material for the project infrastructure and tailings storage facility (“TSF”). As a result, the highest-grade feed material is expected in the first five years of full mine production, with average grades 168 g/t silver and 0.51 g/t gold, resulting in average annual production of 14.5Moz silver and 44koz gold during that period (Table 2 and Figure 1).

Table 2 – Grade and Production Profile

  Units Avg.
Year 1 - 5
Avg. LOM
(Year 1 – 13)
Silver Grades (g/t) 168 91
Gold Grades (g/t) 0.51 0.81
Silver-Equivalent Grades (g/t) 209 155
Silver Production (M oz) 14.5 7.7
Gold Production (k oz) 44.0 71.0
AgEq Production (M oz) 17.9 13.3

Note:  AgEq is calculated using base case prices for silver and gold (Au/Ag price ratio of 78.72)

Figure 1 – Annual Silver Equivalent Production and Grade Profile

Processing and Metallurgy

The process facility has been designed for a nameplate capacity of 9,000 tonnes of mineralization per day (“tpd”), or 3.15 million tonnes per annum (“tpa”) considering 350 days a year of operation.  A conventional silver/gold processing plant flowsheet was developed that incorporates crushing, grinding, gravity concentration, an intense cyanidation circuit, cyanide leaching with oxygen addition, counter current decantation washing thickeners and Merrill-Crowe precious metal recovery from solution followed by on-site smelting to doré bars. The leached solids are detoxified, thickened, and pumped to a TSF for permanent disposal.

Metallurgical test work has been carried out in a range of different laboratories between 1996 and 2023 and all the results have been considered as part of the PFS. A geo-metallurgical model has been developed segregating the deposit into five distinct domains, with overall LOM silver and gold recoveries averaging 82.8% and 86.6%, respectively.  A schematic showing the proposed flowsheet is provided in Figure 2.

Tailings from the process plant will be stored in a multi-phase, fully lined, cross valley TSF. The facility will be raised using the downstream method with the initial starter impoundment, constructed from borrow material and open pit pre-strip waste, providing storage for the first three years of production.

Figure 2 - Process Flowsheet

Operating Costs

The operating cost estimates are based on an owner-operated truck and shovel mining operation, conventional processing plant, and TSF.

The PFS operating cost estimates are shown on a per tonne mined and milled basis in Table 3. The PFS estimates that All-In Sustaining Costs ("AISC") average $9.97/oz AgEq in Year 1 – Year 5, and $12.40/oz AgEq over the LOM.  This AISC is believed to be at the low end of the primary silver production cost curve2.

Table 3 – Mine Operating Cost Estimates

Operating Costs Basis Avg. LOM ($)
Ore Mining per tonne mined 1.94
Waste Mining per tonne mined 1.94
Waste Mining (Overburden) per tonne mined 1.73
Total Mining per tonne milled 13.66
Processing Plant, Utilities and Maintenance per tonne milled 19.26
Camp and Service Hub per tonne milled 3.70
G&A per tonne milled 3.32
Total Operating Cost per tonne milled 39.94

Project Capital Costs

The initial pre-production capital expenditures for the project are summarized in Table 4. Capital expenditures to be incurred after the start-up of operations are assigned to sustaining capital and are projected to be covered by operating cash flows.   Initial capital costs are estimated at $373.5 million and total sustaining capital costs are estimated at $65.0 million. Particular attention was given to the capital cost estimate during the PFS with approximately 80% of the costs based on quoted prices and this has resulted in a lower estimated contingency cost of $20.3 million.  Over 60% of equipment, supplies, construction, and service procurement packages will come from local companies, complying with local regulations.

Table 4 – Summary of Capital Cost Estimates

Description 2021 PEA Study 2024 PFS Change
2024 PFS vs. 2021 PEA
  $ millions $ millions % Change $ Change
Surface Mining 51.6 39.3 -24.0% -12.4
Processing 76.9 96.9 26.1% 20.0
Site Infrastructure 53.7 152.0 183.2% 98.3
Owner and Indirect Costs 46.3 64.9 40.3% 18.7
Contingency & Other Provisions 26.5 20.3 -23.3% -6.2
Initial Capital Costs 255.0 373.5 46.5% 118.5
Sustaining Capital 15.2 65.0 328.0% 49.8
Closure 8.2 11.1 35.5% 2.9
Total Capital Costs 278.4 449.6 61.5% 171.2

Taxes and Royalties

Taxes and royalties in the PFS are based on current Argentinean legislated tax rates and were reviewed by an independent tax consultant. The current rates are:

  • Argentina corporate income tax: 35%
  • Municipal taxes: 0.6%
  • Provincial mining royalty: 3%
  • Gold/Silver export duties: 8% / 4.5%

In total, these taxes, royalties and export duties total $1,087 million in the PFS. The Company believes that the current government of Argentina may implement changes to corporate income taxes and export duties that would have a favourable impact on the PFS economics, although there is no guarantee that such changes will be successfully implemented and approved.

An additional 1% NSR royalty is payable to EMX Royalty Corporation.

Community Relations & Permitting

The Company continues to be very actively involved in community relations and maintains very positive relations with all nearby communities.  The Project is expected to have a positive impact with the creation of new employment opportunities and investment in the region. The PFS estimates that over 65% of the total capital costs will be purchased domestically, and that the majority of local contractors will be hired regionally from Salta, Catamarca and nearby provinces. 

Regarding permitting, the Company has submitted a comprehensive Environmental Baseline Study which is an important milestone towards the ongoing advancement of Diablillos as a sustainable mining project. The Company is now working on finalizing the Environmental Impact Assessment (“EIA”), which is an essential part of the final approval process required for the ultimate construction of the project, and the EIA application is expected to be submitted later this year. 

Summary of Economic Results

Table 5 summarizes the key economic results and parameters of the PFS.

Table 5 – Summary of Project Economics

Metrics Units Results
Life of mine years 13
Total mineralized material mined (Includes Yr. 0) M tonnes 42.3
Total contained silver (Includes Yr. 0) M oz 123.5
Total contained gold (Includes Yr. 0) k oz 1,107.5
Strip ratio (excludes pre-stripping) Waste:ore 6.4
Throughput tpd 9,000
Head grade – silver (first 5 years / LOM) g/t 168 / 91
Head grade – gold (first 5 years / LOM) g/t 0.51 / 0.81
Recoveries – silver (first 5 years / LOM) % 84.4 / 82.8
Recoveries – gold (first 5 years / LOM) % 85.2 / 86.6
Average Production – silver (first 5 years / LOM) M oz 14.5 / 7.7
Average Production – gold (first 5 years / LOM) k oz 44.0 / 71.0
AISC (LOM) – silver equivalent (first 5 years / LOM) $/oz AgEq 9.97 / 12.40
Initial Capital Costs $ M 373.5
Sustaining Capital Costs $ M 65.0
Pre-Tax NPV5% $ M 995.1
After-Tax NPV5% $ M 493.7

Non-IFRS Financial Measures

This news release contains certain non-IFRS measures, including AISC.  AISC includes operating costs, royalties, sustaining capital, closure costs, and corporate G&A and is calculated based on guidance provided by the World Gold Council (“WGC”). WGC is not a regulatory industry organization and does not have the authority to develop accounting standards for disclosure requirements. The Company believes that these measures, together with measures determined in accordance with IFRS, provide investors with an improved ability to evaluate the underlying performance of the Company and the results of the PFS. Non-IFRS measures do not have any standardized meaning prescribed under IFRS, and therefore they may not be comparable to similar measures employed by other companies. The data is intended to provide additional information and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with IFRS.

1 Spot prices: $24.76/oz Ag & $2,180.81/oz Au closing prices on March 21, 2024 (Source: Reuters.com)

2 Please see “Non-IFRS Financial Measures”

4 www.silverinstitute.org/wp-content/uploads/2023/11/SilverMarket2023_interim-report.pdf?v=052404 www.silverinstitute.org/wp-content/uploads/2023/11/SilverMarket2023_interim-report.pdf?v=052404

Visualization of Conceptual Open Pits and Proposed Site Infrastructure at Diablillos

Projects - Diablillos - Mineral Resource Estimate

Mineral Reserve Estimate – As of March 07, 2024

The Table below shows the Proven and Probable Mineral Reserves at Diablillos by deposit. The Mineral Reserves were estimated using a silver price of $22.50/oz and a gold price of $1,750/oz.

Diablillos Mineral Reserve Estimate

Mineral Reserve
(all domains)
Tonnage
(000 t)
Au
(g/t)
Ag
(g/t)
AgEq
(g/t)
Contained Ag
(koz)
Contained Au
(koz)
Contained AgEq
(koz)
Proven 12,364 0.86 177.7 246 46,796 341 97,839
Probable 29,930 0.80 79.7 143 76,684 766 136,267
Total Proven and Probable 42,294 0.81 90.8 154 123,480 1,107 209,619

Notes for Mineral Reserve Estimate:

  1. Mineral reserves have an effective date of March 07, 2024.
  2. The Qualified Person for the Mineral Reserve Estimate is Mr. Miguel Fuentealba, P.Eng.
  3. The mineral reserves were estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), Definition Standards for Mineral Resources and Reserves, as prepared by the CIM Standing Committee on Reserve Definitions and adopted by CIM Council.
  4. The mineral reserves were based on a pit design which in turn aligned with an ultimate pit shell selected from a WhittleTM pit optimization exercise. Key inputs for that process are:
    • Metal prices of U$S 1,750/oz Au; U$S 22.50/oz Ag
    • Variable Mining cost by bench and material type. Average costs are U$S 1.94/t for all lithologies except for “cover” Cover mining cost of U$U 1.73/t, respectively.
    • Processing costs for all zone, U$S 22.97/t.
    • Infrastructure and G&A cost of U$S 3.32/t.
    • Pit average slope angles varying from 37° to 60°
    • The average recovery is estimated to be 82.6% for silver and 86.5% for gold.
  5. The Mineral Reserve Estimate has been categorized in accordance with the CIM Definition Standards (CIM, 2014).
  6. A Net Value per block (“NVB”) cut-off was used to constrain the Mineral Reserve with the reserve pitshell. The NVB was based on "Benefits = Revenue-Cost" being positive, where, Revenue = [(Au Selling Price (US$/oz) - Au Selling Cost (US$/oz)) x (Au grade (g/t)/31.1035)) x Au Recovery (%)] + [(Ag Selling Price (US$/oz) - Ag Selling Cost (US$/oz)) x (Ag grade (g/t)/31.1035)) x Ag Recovery (%)] and Cost = Mining Cost (US$/t) + Process Cost (US$/t) + Transport Cost (US$/t) + G&A Cost (US$/t) + [Royalty Cost (%) x Revenue]. The NVB method resulted in an average equivalent cut-off grade of approximately 46g/t AgEq.
  7. In-situ bulk density was read from the block model, assigned previously to each model domain during the process of mineral resource estimation, according to samples averages of each lithology domain, separated by alteration zones and subset by oxidation.
  8. All tonnages reported are dry metric tonnes and ounces of contained gold are troy ounces.
  9. Mining recovery and dilution factors have not been applied to the Mineral Resource estimates.

November 2023 Mineral Resource Estimate

Diablillos Mineral Resource Estimate – As of November 22, 2023

Deposit Zone Category Tonnes
(000 t)
Ag
(g/t)
Au
(g/t)
AgEq
(g/t)
Contained
Ag
(k oz Ag)
Contained
Au
(k oz Au)
Contained
AgEq
(k oz AgEq)
Oculto Oxides Measured 12,170 101 0.95 178 39,519 372 69,523
Indicated 34,654 64 0.85 133 71,306 947 147,748
Measured &
Indicated
46,824 74 0.88 145 111,401 1,325 218,335
Inferred 3,146 21 0.68 76 2,124 69 7,677
JAC Oxides Measured 1,870 210 0.17 224 12,627 10 13,452
Indicated 3,416 198 0.12 208 21,744 13 22,808
Measured &
Indicated
5,286 202 0.13 212 34,329 22 36,191
Inferred 77 77 - 77 190 - 190
Fantasma Oxides Measured - - - - - - -
Indicated 683 105 - 105 2,306 - 2,306
Measured &
Indicated
683 105 - 105 2,306 - 2,306
Inferred 10 76 - 76 24 - 24
Laderas Oxides Measured - - - - - - -
Indicated 464 16 0.91 89 239 14 1,334
Measured &
Indicated
464 16 0.91 89 239 14 1,334
Inferred 55 43 0.57 89 76 1 157
Total Oxides Measured 14,040 116 0.85 184 52,146 382 82,975
Indicated 39,217 76 0.77 138 95,594 974 174,196
Measured &
Indicated
53,257 87 0.79 151 148,275 1,360 258,087
Inferred 3,288 23 0.66 76 2,415 70 8,049

Notes for November 2023 MRE:

  1. Mineral Resources are not Mineral Reserves and have not demonstrated economic viability.
  2. The formula for calculating AgEq is as follows: Silver Eq oz = Silver oz + Gold oz x (Gold Price/Silver Price) x (Gold Recovery/Silver Recovery).
  3. The Mineral Resource model was populated using Ordinary Kriging grade estimation within a three-dimensional block model and mineralized zones defined by wireframed solids, which are a combination of lithology and alteration domains.  The 1m composite grades were capped where appropriate.
  4. The Mineral Resource is reported inside a conceptual Whittle open pit shell derived using US$ 24.00/oz Ag price, US $1,850/oz Au price, 82.6% process recovery for Ag, and 86.5% process recovery for Au. The constraining open pit optimization parameters used were US $1.94/t mining cost, US $22.97/t processing cost, US $3.32/t G&A cost, and average 51-degree open pit slopes.
  5. The MRE has been categorized in accordance with the CIM Definition Standards (CIM, 2014).
  6. A Net Value per block (“NVB”) cut-off was used to constrain the Mineral Resource with the conceptual open pit. The NVB was based on "Benefits = Revenue-Cost" being positive, where, Revenue = [(Au Selling Price (US$/oz) - Au Selling Cost (US$/oz)) x (Au grade (g/t)/31.1035)) x Au Recovery (%)] + [(Ag Selling Price (US$/oz) - Ag Selling Cost (US$/oz)) x (Ag grade (g/t)/31.1035)) x Ag Recovery (%)] and Cost = Mining Cost (US$/t) + Process Cost (US$/t) + Transport Cost (US$/t) + G&A Cost (US$/t) + [Royalty Cost (%) x Revenue]. The NVB method resulted in an average equivalent cut-off grade of approximately 45g/t AgEq.
  7. The Mineral Resource is sub-horizontal with sub-vertical feeders and a reasonable prospect for eventual economic extraction by open pit methods.
  8. In-situ bulk density was assigned to each model domain, according to samples averages of each lithology domain, separated by alteration zones and subset by oxidation.
  9. All tonnages reported are dry metric tonnes and ounces of contained gold are troy ounces.
  10. Mining recovery and dilution factors have not been applied to the Mineral Resource estimates.
  11. The Mineral Resource was estimated by Mr. Luis Rodrigo Peralta, B.Sc., FAusIMM CP (Geo), Independent Qualified Person under National Instrument 43-101 - Standards of Disclosure for Mineral Projects (“NI 43-101”).
  12. Mr. Peralta is not aware of any environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues that could materially affect the potential development of the Mineral Resource.
  13. All figures are rounded to reflect the relative accuracy of the estimates. Minor discrepancies may occur due to rounding to appropriate significant figures.
  14. Totals may not agree due to rounding.

Mineral Resource Estimate Methodology

  • The November 2023 MRE was completed by Luis Rodrigo Peralta, B.Sc., FAusIMM CP (Geo), Independent Consultant, in accordance with Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definition Standards incorporated, by reference, and in compliance with NI 43-101, and has been reviewed internally by AbraSilver.
  • The MRE is the result of approximately 133,000 metres of drilling in 630 drill holes (historical and current). This includes the latest Phase III drill campaign, conducted in 2022/23, which totaled 24,077 metres.
  • The MRE is based on the Oculto, JAC, Fantasma and Laderas deposits within the broader Diablillos property and is reported inside a conceptual Whittle open pit shell.  The cut-off grade was calculated using a Net Block Value calculation, based on the economic parameters outlined in the footnotes to the Table above.
  • Gold and silver grades were estimated into the block model using reverse circulation drill holes, diamond drill holes including the recent drilling between 2019 to July 30th, 2022. They were estimated applying the industry-standard estimation methodology of ordinary kriging and bias was reviewed using an inverse distance squared estimate for comparison. Drill hole intervals have been composited to a length of 1 m, which is the average sampling length for core sampling.
  • Grade capping has been applied to composited grade intervals on a case-by-case basis within each estimation domain. The estimation domains were defined using a combination of lithology domains, alteration domains, and oxide / sulphides state, defining a set of 24 domains for gold and silver.

Significant Exploration Upside Potential

Numerous opportunities exist to further expand the Mineral Resources within the existing deposits, in addition to defining new mineralized zones through a step-out exploration drill campaign.  The Company is currently prioritizing and sequencing the various targets ahead of the next exploration campaign which is expected to commence in Q1/2024.

  • Oculto: MRE is based on a total of 457 drill holes, or approximately 104,800 metres.   Additional drilling would focus on expansion of the highest-grade portion of Oculto, the Tesoro Zone, and exploration of potential continuation of mineralization along known zones towards the northeast.
  • JAC:  The new high-grade JAC deposit was discovered in August 2022 and the maiden MRE is based on a total of 112 drill holes, or approximately 20,800 metres.   Additional drilling would focus additional mineralized zones within the JAC magnetic low zone.
  • Fantasma:  MRE is based on a total of 39 drill holes, or approximately 4,300 metres.   Additional drilling would focus on the potential continuity of mineralization along the approximately one kilometre zone connecting the Fantasma body to the Oculto deposit.
  • Laderas:  MRE is based on a total of 22 drill holes, or approximately 3,200 metres.   Additional drilling would focus on continuity of the higher grade parts of the zone, as well as northeast extensions.
  • Other Priority Targets Beyond the Current MRE:  Reconnaissance exploration, in combination with structural mapping and magnetic surveys, continues to generate new targets in other underexplored areas of Diablillos.  These targets include JAC North and Alpaca, neither of which have been included in the MRE due to insufficient drilling, as well as other zones with similar geological characteristics, where additional drilling is also warranted. 
    • JAC North: Initial drilling on the northern edge of the JAC deposit intersected a new zone of silver mineralization, JAC North, suggesting the possibility of a structure within the magnetic low anomaly parallel to the JAC deposit. This new target will be followed up in the next drill program.
    • Alpaca:  Historical drilling intersected silver mineralisation in the Alpaca area, located several hundred meters northwest of JAC. An interpretation of the magnetic signature suggests that a perpendicular zone of silver mineralisation may connect JAC with Alpaca. This is a high priority for the next drilling campaign.

Supporting Technical Disclosure

  • Metallurgical recoveries: Metallurgical recoveries used in the MRE and open pit optimization were based on a new geo-metallurgical model built using recent metallurgical test works performed at the SGS Laboratory in Vancouver. This new model incorporates five domains, based on a master composite for each, comprised of approximately 15 samples per domain. A fixed value of metallurgical recovery has been applied to each domain. Overall weighted average recoveries of these five domains are 82.6% for silver and 86.5% for gold.  
  • Open pit slopes: Open pit shell slope angles at Oculto are based on the 2022 geotechnical drilling and subsequent modelling. Six geotechnical sectors have been defined for use in the open pit optimization with the angles varying between 35 degrees in the unconsolidated overburden to 55 degrees in the granitic rock type, with the average overall angle being 51 degrees. As the JAC deposit is covered with unconsolidated colluvium a conservative pit slope angle of 35 degrees was used. Importantly the overburden at the JAC deposit is expected to be free-digging, resulting in lower mining costs.
  • Updated operating cost estimates from the ongoing PFS have been used in the Net Value per Block method, totaling US$28.23/tonne processed, and these have been based on 73% firm quotations.
  • A full Technical Report in respect of the November 2023 MRE will be prepared in accordance with NI 43-101 and will be filed on SEDAR+

Qualified Persons and Technical Information

The site visit, review of various geological aspects including sampling, drill core, logging, assay laboratory, independent check sample and November 2023 Mineral Resource estimate were done by Mr. Luis Rodrigo Peralta, B.Sc., FAusIMM CP (Geo). Mr. Peralta is an independent Qualified Person (“QP”) as defined by the NI 43-101.

Diablillos Phase III Exploration Campaign

The 22,000-metre Phase III drill program at the Diablillos project was successfully completed in August 2023.   The drill program achieved all of the main objectives, which are summarized below:

  • Systematically drill off silver-dominant mineralisation at the JAC zone in order to estimate Measured and Indicated Mineral Resources that are incorporated into an updated Mineral Resource estimate and Pre-Feasibility Study on Diablillos.
  • Delineate the margins of the JAC zone mineralization and conduct geotechnical drilling necessary for a conceptual open pit design.
  • Conduct reconnaissance drilling at other targets on the Diablillos land package (including JAC North, Fantasma and Alpaca).

As part of the Phase III campaign, the Company discovered the new high-grade JAC zone, for which a maiden resource was announced on November 27, 2023.

Highlights of selected high-grade drill results at JAC reported from the Phase III drill program are summarized in the Table below:

JAC Zone – Highlights of Phase III High-Grade Intercepts at JAC

Drill Hole From (m) To
(m)
Type Interval
(m)
Ag
(g/t)
Au
(g/t)
AgEq1 (g/t)
DDH-22-019 89.0 176.0 Oxides 87.0 346.0 0.15 356.5
DDH-22-044 121.0 179.0 Oxides 58.0 208.8 0.20 222.8
DDH-22-046 123.0 165.5 Oxides 42.5 400.5 0.11 408.2
DDH-22-052 139.5 164.5 Oxides 25.0 754.4 0.12 764.2
DDH-22-053 140.5 168.5 Oxides 28.0 266.4 0.64 318.8
DDH-22-056 110.0 167.5 Oxides 57.5 141.4 0.27 163.5
DDH-22-057 144.0 164.0 Oxides 20.0 498.6 0.10 506.8
DDH-22-058 138.0 152.5 Transition 14.5 176.2 - 176.2
DDH-22-060 114.0 154.0 Oxides 40.0 203.4 - 203.4
DDH-22-061 65.0 168.0 Oxides 103.0 138.7 - 138.7
DDH-22-062 119.0 170.0 Oxides 51.0 169.4 0.20 185.8
DDH-22-063 56.0 85.0 Oxides 33.0 143.4 - 143.4
DDH-22-063 135.0 169.0 Oxides 34.0 118.6 0.08 125.2
DDH-22-067 143.0 179.0 Oxides 36.0 463.3 0.71 521.5
DDH-22-067 179.0 206.0 Sulphides 27.0 745.0 1.54 871.1
DDH-22-075 151.0 167.0 Oxides 16.0 604.4 0.82 671.5
DDH-22-076 147.0 169.0 Oxides 22.0 476.8 0.20 493.2
DDH-22-076 169.0 177.5 Oxides 8.5 1,952.8 6.66 2,498.3
DDH-22-077 60.0 92.0 Oxides 32.0 121.9 - 121.9
DDH-22-078 58.0 99.0 Oxides 41.0 103.5 - 103.5
DDH-22-079 144.0 179.0 Oxides 35.0 199.2 0.36 228.7
DDH-22-080 50.0 102.0 Oxides 52.0 125.1 - 125.1
DDH-22-081 128.0 165.0 Oxides 37.0 179.3 - 179.3
DDH-22-082 154.5 181.0 Transition 26.5 311.4 0.43 346.6
DDH-22-083 159.0 184.0 Transition 25.0 773.8 0.28 796.7
DDH-22-086 158.0 167.0 Sulphides 9.0 342.3 - 342.3
DDH-23-002 148.0 165.0 Transition 17.0 288.6 0.14 300.1
DDH-23-003 155.8 161.5 Sulphides 5.8 502.2 - 502.2
DDH-23-004 136.0 150.0 Oxides 14.0 3,024.5 0.21 3,041.7
DDH-23-007 115.0 119.0 Oxides 4.0 2,320.0 - 2,320.0
DDH-23-009 161.0 169.5 Oxides 8.5 479.2 0.15 491.5
DDH-23-010 132.0 177.5 Oxides 45.5 233.4 - 233.4
DDH-23-014 127.0 173.5 Oxides 46.5 185.0 0.50 226.0
DDH-23-017 92.0 104.0 Oxides 12.0 876.1 - 876.1
DDH-23-021 161.5 193.5 Oxides 32.0 530.8 0.60 579.9
DDH-23-024 144.0 161.0 Oxides 17.0 828.9 - 828.9
DDH-23-025 100.0 179.0 Oxides 79.0 237.6 0.15 249.9
DDH-23-036 140.0 150.0 Oxides 10.0 520.0 0.04 523.3
DDH-23-039 105.0 124.0 Oxides 19.0 253.4 - 253.4
DDH-23-046 157.0 160.0 Oxides 3.0 2,070.0 0.27 2,092.1
DDH-23-050 156.5 167.0 Oxides 10.5 281.4 - 281.4
DDH-23-061 134.0 153.5 Oxides 19.5 272.8 - 272.8
DDH-23-070 41.0 105.0 Oxides 64.0 148.1 - 148.1

Note: All results are rounded. Assays are uncut and undiluted. Widths are drilled widths, not true widths. True widths are estimated to be approximately 80% of the interval widths.

1 AgEq based on 81.9(Ag):1(Au) calculated using long-term prices of US$25.00/oz Ag and US$1,750/oz Au, and 73.5% process recovery for Ag, and 86.0% process recovery for Au as demonstrated in the Company’s PEA in respect of Diablillos dated January 13, 2022, using formula:  AgEq g/t = Ag g/t + Au g/t x (Gold Price/Silver Price) x (Gold Recovery/Silver Recovery).

Metallurgical Overview 

The Diablillos project is expected to have a conventional silver/gold processing plant flowsheet incorporating crushing, grinding, gravity concentration and intense cyanidation circuit, cyanide leaching with oxygen addition, counter current decantation (“CCD”) washing thickeners and Merrill-Crowe precious metal recovery from solution followed by on-site smelting to doré bars. A summary of the processing flow sheet for the Diablillos project is shown below.

Recent Positive Metallurgical Test Results

Oculto Deposit

On October 10, 2023 the Company reported positive results from metallurgical optimization testing on the Oculto deposit.  The metallurgical testing was conducted as part of the ongoing Pre-Feasibility Study ("PFS") for Diablillos.

Key takeaways from the PFS-level metallurgical test work include:

  • Recovery rates at the Oculto deposit are expected to range between 82% - 86% for silver and 84% - 89% for gold. These results represent a significant increase over the average recovery rates of 73.5% for silver and 86% for gold used in the 2022 Preliminary Economic Assessment (“PEA”).
  • A substantial percentage of the silver and gold at Oculto can be recovered by gravity separation which results in higher recovery rates and lower processing costs
  • Importantly, fine grinding is not necessary with the most efficient recoveries achieved at a grind size of 150 microns for both gravity and cyanidation and an optimal retention time of 36 hours. 

JAC and Fantasma Deposits

The Company reported positive preliminary metallurgical test results for the new JAC zone on June 01, 2023.

Key Highlights Include:

  • Overall recoveries at the JAC and Fantasma deposits range between 86% - 93% for silver and 82% - 91% for gold.
  • A substantial percentage of the silver at JAC can be recovered by gravity separation which increases overall recoveries.
  • Current testwork confirms that the same process flowsheet can be used to process mineralization from the Oculto, JAC and Fantasma deposits. 
  • Milling tests have shown that 150 microns is the targeted grind size for the leaching of the mineralized material at a retention time of 36 hours.
  • Overall silver and gold recoveries could likely be increased further by grinding finer and with higher cyanide concentrations. Further metallurgical testwork and trade-off studies are now underway.

Favorable Recovery Rates

At the JAC and Fantasma deposits the silver minerals (chlorargyrite and iodargyrite) are easier to release by grinding, and are more sensitive to cyanide leaching as they occur in argillic alteration, whereas at Oculto they are mostly held more complexly in vuggy silica host rock.

Summary of Metallurgical Testwork Results for JAC and Fantasma Deposits

Target Silver
Recoveries
Silver
Head Grades
 Gold Recoveries Gold
Head Grades
% g/t % g/t
JAC & FANTASMA 86 - 93 142 - 172 82 - 91 0.11 - 0.17

Testwork on JAC and Fantasma samples showed that gravity separation before cyanide leaching recovers approximately 9% of the silver and 17% of the gold which, when combined with the subsequent cyanide leaching recoveries, results in total overall recoveries of between 86% and 93% for silver and between 82% and 91% for gold.

The Diablillos property hosts several zones of high-sulphidation epithermal alteration and mineralization with strong supergene overprinting. There are several known mineralized zones on the Diablillos property, with the Oculto zone hosting the principal silver-gold deposit. Oculto is strongly oxidized down to depths in the order of 300 m to 400 m from surface with oxide gold and silver mineralization overlying a pronounced copper sulphide zone extending beneath. The sulphide mineralization has an enriched copper layer with chalcocite coating chalcopyrite and pyrite, with associated variably high grades of gold and silver. Primary copper sulphide mineralisation extends to considerable depths towards the base of the mineralised system. The precious metal mineralization throughout the oxide zone of the deposit occurs as extremely fine grains along fractures and in breccias or coating the inside of vugs and weathered cavities. The dimensions of the optimised Whittle open pit shell measure 1,350 metres in length, 750 metres in width and extends to a maximum depth of approximately 300 metres.

Gold and silver mineralization ascended along steeply dipping feeder structures and was deposited in siliceous breccia zones. Mineralizing fluids also migrated laterally along shallowly dipping favorable permeability horizons where it was deposited along with silicification. Gold is associated with a deeper permeability horizon and with shallow zones associated with the feeder structures, while there is a secondary enriched silver zone related to a weathered horizon.

Diablillos Geological Model: Near-Surface Epithermal Ag-Au Deposit, With Cu-Au Porphyry Intrusive at Depth

The Table below highlights reported drill intercepts in sulphide mineralization, from the limited amount of deeper drilling conducted at Diablillos to date. 

Highlights of Selected High-Grade Intercepts in Sulphide Minerlization at Diablillos

Drill Hole From
(m)
To
(m)
Interval
(m)
Cu
(%)
Au
(g/t)
Ag (g/t)
DDH-19-002 369 401 32 1.26 2.20 24.6
DDH-19-002 438 446 8 2.11 0.47 32.7
DDH-20-001 268 271 3 1.06 3.45 339.1
DDH-20-001 275 303 28 3.25 1.60 358.3
DDH-20-002 337 349 12 1.74 1.14 12.3
DDH-20-003 446 446.5 0.5 6.37 0.56 12.3
DDH-20-006A 293 315.5 22.5 0.52 0.35 9.45
DDH-20-007 265 270 5 1.54 0.03 98.5
DDH-20-007 376 377 1 1.22 2.34 51.6
DDH-20-008 350 361 11 1.58 1.27 12.7
DDH-20-010A 313.5 320.5 7 0.99 2.18 17.8
DDH-20-019 146 173 27 1.37 0.20 31.0
DDH-21-009 311 316 5 0.90 2.14 10.3
DDH-21-009 354 356 2 0.66 1.73 37.7
DDH-21-020 302.5 324 21.5 1.76 - -
DDH-21-024 275 287 12 1.40 2.98 26.8
DDH-21-040 272 277 5 4.20 3.22 49.5
DDH-22-021 368.5 379.5 11 2.00 0.30 5.49
DDH-22-043 215 227 12 3.63 0.29 3,664.9
DDH-22-067 185 195 10 2.55 0.73 590.3
DDH-22-067 197 206 9 0.75 1.25 534.4
DDH-22-078 181 198.5 17.5 1.54 0.01 25.5
DDH-22-083 162.5 171 8.5 3.36 0.10 694.7
DDH-22-086 158 172 14 1.18 - -
DDH-23-009 169.5 183 13.5 0.64 0.06 184.9
DDH-23-025 179 212.5 33.5 3.03 0.01 88.5
DDH-23-046 157 160 3 1.11 0.27 2,070.0
DDH-23-062 155 163 8 1.04 0.01 60.7

Note: All results are rounded. Assays are uncut and undiluted. Widths are drilled widths, not true widths. True widths are estimated to be approximately 80% of the interval widths.

Over US$50 million has been spent on exploration at Diablillos totaling over 100,000 meters of drilling in over 450 holes.

Year Operator Description
1983 Secretaría de Minería de la Nación 1,409 rock chip samples (includes 190 outcrop and 271 slope debris samples from Diablillos Sur)
1984 - 1987 Shell C.A.R.S A Rock geochemical survey; three Winkie drill holes
1987 Ophir Partnership 37 rotary drill holes (approximately 30 m deep) in the Corderos, Pedernales, Laderas, and Jasperoide areas
1989 - 1991 BHP Geological mapping (1:1,000 to 1:7,500 scale); 380 rock chip samples; 1,200 m of bulldozer trenches; 55 air RC holes (6,833 m)
1993 Pacific Rim Mining Corporation Five diamond drill holes (1,001.8 m) in the Oculto Zone
1994 Pacific Rim Mining Corporation 148 km of chain and compass grid; geological mapping; 122 line-km of ground magnetic survey; 34 line-km of induced polarization (IP) survey; 213 hand auger samples; 2.5 km of trenching; 250+ rock chip samples; 12 diamond drill holes (2,013.9 m)
1996 - 1997 Barrick Gold Corp Geological mapping; surface sampling; RC drilling; CSAMT survey; mag survey; environmental impact study; metallurgical test work
2003 Pacific Rim Mining Corporation
(for Silver Standard)
20 diamond drill holes (3,046 m)
2005 Pacific Rim Mining Corporation
(for Silver Standard)
Five diamond drill holes each at Renacuajo and Alpaca
2007 Pacific Rim Mining Corporation
(for Silver Standard)
45 diamond drill holes (9,600 m) on Oculto; one hole (203 m) at Laderos; three holes (unknown length) at Pedernales; five holes (unknown length) at Los Corderos; four HQ-size diamond drill holes sampled for metallurgical tests
2008 Pacific Rim Mining Corporation
(for Silver Standard)
52 diamond drill holes (7,910 m), three of these for geotechnical studies; additional metallurgical studies
2009 Silver Standard Resources Mineral Resource estimate
2011 - 2012 Silver Standard Resources Internal Preliminary Economic Assessment, rock chip sampling, 1,679 m diamond drilling (19 holes)
2017 AbraSilver 28 drillholes and a total of 3,148.5m
2018 AbraSilver Preliminary Economic Asessment including Resource estimate
2019 AbraSilver Phase I Drilling Campaign with 2 diamond drill holes (844 m),
2020 - 2021 AbraSilver Phase II Drilling Campaign of 55 drillholes and a total of 15,143 m expanding Oculto to North, West and East and testing new targets
2022 - 2023 AbraSilver  Phase III Drilling Campaign completed totalling over 24,000 m, resulting in the discovery of hte new high-grade JAC deposit for which a maiden resource was announced in November 2023

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