from Silver Tiger Metals Inc. (isin : CA82831T1093)
Silver Tiger Announces PFS With NPV of US$222M for the Stockwork Zone of the El Tigre Silver-Gold Project, Sonora, Mexico
HALIFAX, NS / ACCESSWIRE / October 22, 2024 / Silver Tiger Metals Inc. (TSXV:SLVR)(OTCQX:SLVTF) ("Silver Tiger" or the "Corporation") is pleased to announce a Preliminary Feasibility Study ("PFS") for its 100% owned, silver-gold El Tigre Project (the "Project" or "El Tigre") located in Sonora, Mexico. The PFS is focused on the conventional open pit mining economics of the Stockwork Mineralization Zone defined in the updated Mineral Resource Estimate ("MRE") (Figure 1). The updated MRE also contains an Out-of-Pit Mineral Resource that Silver Tiger plans to study in a Preliminary Economic Assessment in H1-2025.
Highlights of the PFS are as follows (all figures in US dollars unless otherwise stated):
After-Tax net present value ("NPV") (using a discount rate of 5%) of US$222 million with an After-Tax IRR of 40.0% and Payback Period of 2.0 years (Base Case);
10-year mine life recovering a total of 43 million payable silver equivalent ounces ("AgEq") or 510 thousand payable gold equivalent ounces ("AuEq"), consisting of 9 million silver ounces and 408 thousand gold ounces;
Total Project undiscounted after-tax cash flow of US$318 million;
Initial capital costs of $86.8 million, which includes $9.3 million of contingency costs, over an expected 18-month build, expansion capital of $20.1 million in year 3 and sustaining capital costs of $6.2 million over the life of mine ("LOM");
Average LOM operating cash costs of $973/oz AuEq, and all in sustaining costs ("AISC") of $1,214/oz AuEq or Average LOM operating cash costs of $12/oz AgEq, and all in sustaining costs ("AISC") of $14/oz AgEq;
Average annual production of approximately 4.8 million AgEq oz or 56.7 thousand AuEq oz; and
Three (3) years of production in the Proven category in the Phase 1 Starter Pit.
Glenn Jessome, President & CEO stated "We are very pleased with the work completed by our consultants and our technical team on the PFS for the open pit at El Tigre. The open pit delivers robust economics with an NPV of US$222 million, an initial capital expenditure of US$87 million, and a payback of 2 years with 3 years of production in the Proven category in the ‘Starter Pit using metal prices greatly discounted to the spot price." Mr. Jessome continued "This is a pivotal point for our Company as we now have a clear path forward to making a construction decision for the open pit. The open pit has good grade (48 g/t AgEq), low strip ratio (1.7:1), and wide benches (~150 m) with mineralization at surface. With such positive parameters and with our VP of Operations Francisco Albelais, a career expert in the construction of large heap leach mines in Mexico, we are confident we will be able to advance the Project very quickly." Mr. Jessome concluded "The open pit is only one component of El Tigre as we have also today delivered over 113 Mozs AgEq in the underground Mineral Resource Estimate and disclosed an Exploration Target establishing 10 to 12 million tonnes at 225 to 265 g/t AgEq for 73 to 100 Moz AgEq. This disclosed ‘near-mine' Mineral Resource and potential, when coupled with the fact that only 30% of this prolific Property has been explored, shows the value of the El Tigre Project. The Company will also continue to work on this substantial underground Mineral Resource by starting underground drilling immediately, and plan to release an underground PEA in H1-2025."
Highlights of the updated Mineral Resource
Increased confidence in MRE, with increase of 132% in Total Measured & Indicated Silver Equivalent ("AgEq") Ounces from September 2023 MRE, with 59% increase in Measured & Indicated AgEq grade;
Total Measured & Indicated Mineral Resource of 200 Moz AgEq grading 92 g/t AgEq contained in 68.0 million tonnes ("Mt");
Inferred Mineral Resource of 84 Moz AgEq grading 180 g/t AgEq contained in 14.5 Mt; and
Inclusion of Out-of-Pit Mineral Resource of 5.3 Mt Measured & Indicated Mineral Resource at grade of 255 g/t AgEq and 10.1 Mt Inferred Mineral Resource grading 216 g/t AgEq.
Preliminary Feasibility Summary
The PFS was prepared by independent consultants P&E Mining Consultants Inc. ("P&E"), with metallurgical test work completed by McClelland Laboratories, Inc. - Sparks, Nevada, process plant design and costing by D.E.N.M. Engineering Ltd., and environmental and permitting led by CIMA Mexico. Following are tables and figures showing key assumptions, results, and sensitivities.
Table 1: El Tigre PFS Key Economic Assumptions and Results (1-2)
Assumption / Result | Unit | Value | Assumption / Result | Unit | Value | |
---|---|---|---|---|---|---|
Total OP Plant Feed Mined | kt | 40,292 | Net Revenue | US$M | 1,093 | |
Operating Strip Ratio | Ratio | 1.7:1 | Initial Capital Costs | US$M | 87 | |
Silver Grade 1 | g/t | 14.9 | Expansion Capital Costs | US$M | 15 | |
Gold Grade 1 | g/t | 0.40 | Sustaining Capital Costs | US$M | 11 | |
Silver Recovery (Oxide/Sul.) 2 | % | 45 / 40 | Mining Costs | $/t Material | 2.24 | |
Gold Recovery (Oxide/Sul.) 2 | % | 83 / 56 | Processing Costs (Phase 1 and Phase 2) | $/t Feed | 5.79/4.74 | |
Silver Price | US$/oz | 26.00 | G&A Costs | $/t Feed | 1.27 | |
Gold Price | US$/oz | 2,150 | Operating Cash Cost | US$/oz AgEq | 11.6 | |
Payable Silver Metal | Moz | 8.57 | All-in Sustaining Cost | US$/oz AgEq | 14.4 | |
Payable Gold Metal | koz | 408 | After-Tax NPV (5% discount) | US$M | 222 | |
Payable AgEq | Moz | 42.9 | Pre-Tax NPV (5% discount) | US$M | 342 | |
Mine Life | Yrs | 10 | After-Tax IRR | % | 40.0 | |
Average mining rate | t/day | 30,000 | Pre-Tax IRR | % | 51.2 | |
After-Tax Payback Period | Yrs | 2.0 |
Grades shown are LOM average process plant feed grades include only OP sources. Mining losses and external dilution of 3.7% were incorporated in the mining schedule.
Column testing indicated both variable gold and silver recovery for the oxide material vs the previously reported non-discounted PEA (83% and 64%) at a 3/8-in crush size. In the process design and financial model for the PFS process design and financial model recoveries have been discounted by 3% for leaching in the field versus optimum conditions in the laboratory and shown accordingly. The presence of transition and sulfide zones has affected both the gold and silver recoveries and are shown as separate recoveries. These are reasonable and appropriate for use in this PFS design and economic analysis.
Figure 2: El Tigre Cash Flow Profile by Year
Figure 2 above highlights the post-tax cash flows of US$318 million associated with the El Tigre Project. The economics of the Project have been evaluated based on the base case scenario $26/oz silver price and gold price of $2,150/oz. As illustrated in the following sensitivity tables, the Project remains robust even at lower commodity prices or with higher costs (Tables 2 and 3).
Table 2 - El Tigre PFS Gold and Silver Price Sensitivities
Sensitivity | Base Case | ||||||
---|---|---|---|---|---|---|---|
Silver Price (US$/oz) | 18 | 22 | 26 | 30 | 34 | 38 | 42 |
Gold Price (US$/oz) | 1,500 | 1,750 | 2,150 | 2,500 | 2,750 | 3,000 | 3,250 |
After-Tax NPV (5%) (US$M) | 55.9 | 123.9 | 221.5 | 308.7 | 375.6 | 442.5 | 509.4 |
After-Tax IRR (%) | 15.8 | 26.7 | 40.0 | 50.2 | 57.2 | 63.9 | 70.3 |
After-Tax Payback (years) | 4.5 | 3.4 | 2.0 | 1.7 | 1.6 | 1.4 | 1.3 |
Table 3 - El Tigre PFS Operating Cost and Capital Cost Sensitivities
Sensitivity | -20% | -10% | Base Case | 10% | 20% |
---|---|---|---|---|---|
Operating Costs - NPV (5%) (US$M) | 270.4 | 246.0 | 221.5 | 194.2 | 169.6 |
Operating Costs - IRR (%) | 46.2 | 43.2 | 40.0 | 36.1 | 32.7 |
Capital Costs - NPV (5%) (US$M) | 236.7 | 229.1 | 221.5 | 211.1 | 203.4 |
Capital Costs - IRR (%) | 48.5 | 43.9 | 40.0 | 36.1 | 33.2 |
Capital and Operating Costs
The El Tigre Project has been envisioned as an open pit mining operation starting at a processing rate of 7,500 tonnes per day for years 1-3 and then ramping up to 15,000 tonnes per day by year 4 after 1 year construction for ramp up in year 3.
The process plant is comprised of conventional three (3) stage crushing to an optimum -3/8 inch (10 mm) crush size. The crushed material will be conveyed and loaded on the lined pad areas. A series of pumping and piping will allow irrigation of the stacked heap material and subsequent production of pregnant solution to flow to the respective impoundment pond. The pregnant solution will be pumped to the recovery facility consisting of the Merrill - Crowe process (zinc precipitation) and refinery to produce the gold and silver dore for marketing. The process barren solution will be recycled (with NaCN addition) and pumped back to the heap for further leaching. The process plant location will be adjacent to the pad and pond infrastructure area.
Water supply to the process plant is provided by pumping from nearby Bavispe River to the process area water distribution system and high voltage grid power will be installed by the local utility to supply process and infrastructure electrical requirements. Expansion capital includes the cost to increase the process plant capacity from 7,500 tonnes per day to 15,000 tonnes per day as noted in Year 4 of operation.
Table 4 - LOM Capital Cost Estimate
Type | Initial | Expansion | Sustaining | Total |
(US$k) | (US$k) | (US$k) | (US$k) | |
Process Plant direct costs | 42,851 | 13,584 | 1,600 | 58,034 |
Mining direct costs | 2,660 | 4,362 | 3,956 | 10,978 |
Pre-stripping | 3,362 | 3,362 | ||
Infrastructure | 20,489 | 20,489 | ||
Process indirect costs (with EPCM) | 8,121 | 8,121 | ||
Total | 77,483 | 17,946 | 5,556 | 100,985 |
Contingency (12%) | 9,298 | 2,199 | 622 | 12,118 |
Total with Contingency | 86,780 | 20,145 | 6,178 | 113,103 |
Mining
Open pit mining will be contracted and carried out by drill and blast followed by conventional loading and truck haulage to the waste rock storage facilities and the process plant.
Metallurgy
A detailed metallurgical test program was carried out by McClelland Laboratories, Inc., Sparks, Nevada on six (6) El Tigre starter pit samples. The program included crushing, coarse bottle rolls, and column testing at both 80% passing 3/8 inch and 1/2 inch (10 and 12 mm) crush size for five (5) of the six samples. One low grade sample was only crushed to 80% passing 1-1/2 inch (38 mm) as an indication of low grade leachability. The leach samples comprised of drill core sample representing the starter pit and during the testing process it became apparent that the presence of transition and sulfide zones are in the starter pit thus affecting the base design recoveries. This variable test program (column and coarse bottle roll) estimated oxide average gold and silver respective metallurgical recoveries of 86% Au and 48% Ag at the 3/8 inch (10 mm) crush. The transition and sulfide zones had estimated recoveries of 59% Au and 43% Ag. Further percolation testing also confirmed no requirement for agglomeration of the crushed material is required prior to loading on the leach pad.
Mineral Resource Estimate
The basis for the PFS is the Mineral Resource Estimate completed by P&E for the El Tigre Project located in Sonora State, Mexico, which has an effective date of October 22, 2024, with an NI 43-101 Technical Report to be filed within 45 days of this news release. A summary of the Mineral Resource Estimate is provided in Table 5.
Table 5 - Updated Mineral Resource Estimate October 2024
Mineral Resources, which are not Mineral Reserves, do not have demonstrated economic viability. The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.
The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of the Inferred Mineral Resource could be upgraded to an Indicated Mineral Resource with continued exploration.
The Mineral Resources were estimated in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions and adopted by the CIM Council.
Historically mined areas were depleted from the Mineral Resource model.
Prices used are US$2,000/oz Au, US$25/oz Ag, US$4.00/lb Cu, US$0.95 lb Pb and US$1.25/lb Zn.
The pit-constrained AuEq respective oxide and sulfide cut-off grades of 0.10 and 0.15 g/t were derived from 40% Ag and 83% Au oxide process recovery, 40% Ag and 56% Au sulfide process recovery, US$5.25/tonne process and G&A cost. The constraining pit optimization parameters were $2.00/t mining cost and 45-degree pit slopes. Regarding recoveries, the PFS recovery for Ag in oxide material was increased to 45% after a more detailed study was complete after the MRE was finalized.
The out-of-pit AuEq cut-off grade of 1.50 g/t was derived 93% Ag and 89% Au process recovery, US$28/tonne process and G&A cost, and a $60/tonne mining cost. The out-of-pit Mineral Resource grade blocks were quantified above the 1.50 g/t AuEq cut-off, below the constraining pit shell and within the constraining mineralized wireframes. Out-of-Pit Mineral Resources are restricted to the El Tigre Main Veins, which exhibit historical continuity and reasonable potential f