Producing

GC Mine

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Introduction

  • 99%-owned Gaocheng (GC) operations consist of a ~310 ktpa underground mine and a sulphide flotation plant
  • Located approximately 200 km west of Guangzhou, the capital city of Guangdong Province, China
  • Acquired from a private Chinese company in April 2008
  • Construction began shortly after mining permit receipt in late 2010. The permit covers a 5.5 km2 area and is valid until November 24, 2040
  • Achieved commercial production in 2014 and has since contributed over 6 Moz of silver and 235 Mlb of lead and zinc
  • Produces silver-lead, zinc and minor tin concentrates sold to smelters in China
  • Current reserves support mining through 2034
  • Mine life extension through resources to reserves conversion drilling and further generative exploration/development

GC Operation Snapshot

Mine Life 1

13 Years

Silver Production

FY2022A: 640 koz
FY2023A: 593 koz
FY2024A: 527 koz

FY2025E: 540-550 koz

AISC 2

FY2022A: US$79.56/t
FY2023A: US$83.33/t
FY2024A: US$85.17/t

FY2025E: US$99.3-$99.7/t

1 Gaocheng Technical Report effective March 31, 2021.

2 AISC refers to all-in sustaining costs per tonne of ore processed.

Mining

Mine Type Ramp and Shaft supported underground
Mining Method Re-suing and shrinkage
Reserve tonnage 2 4,131 kt
Reserve grades 2 94 g/t silver
1.48% lead
3.22% zinc
Peak annual ore production 318 kt
Primary metal Silver
By-product metals Lead, zinc, tin

1 Gaocheng Technical Report effective March 31, 2021.

2 AISC refers to all-in sustaining costs per tonne of ore processed.

Mineral Processing

  • The overall process consists of:
    • Two-stage crushing
    • Two-stage grinding
    • Sequential flotation of lead, zinc and pyrite concentrates
    • Concentrate de-watering by disc filtration
  • An experimental tin recovery (gravity) circuit was installed on pyrite flotation tails
  • Tailings are de-watered, then back-filled underground or dry-stacked
  • Mill throughput to date has generally been between 900 and 950 tpd (~310 ktpa)

Exploration and Geology

Recent Work/ Highlights

Silvercorp completed 72,878 m of underground drilling in 704 diamond drill holes at the GC mine from October 1, 2019 to June 30, 2021. The program targeted: 1) known silver-lead-zinc veins in and above the production area that were previously missed due to limited exploration, changes in the strikes/dips, and/or pinch-swelling of the pay-zones, and 2) the north and south sides of the resource area at higher elevations.

 

High-grade intercepts of known silver-lead-zinc veins within the production area:

  • Hole 20CK24A02 intersected a 6.13 m interval (6.01 m true width) of vein V2E1 grading 258 g/t silver, 7.05% lead, and 7.05% zinc from 53.41 m depth, at an elevation of -211 m, including a 1.10 m interval (1.08 m true width) grading 462 g/t silver, 25.57% lead, and 5.21% zinc.
  • Hole 20CK3025 intersected a 2.93 m interval (2.79 m true width) of vein NV28 grading 417 g/t silver, 19.22% lead, and 1.72% zinc from 38.96 m depth, at an elevation of -11 m, including a 1.48 m interval (1.34 m true width) grading 815 g/t silver, 37.47% lead, and 2.12% zinc.

 

High-grade intercepts of newly discovered silver-lead-zinc veins within the production area:

  • Hole 20CK11805 intersected a 0.74 m interval (0.74 m true width) of vein V18-3 grading 557 g/t silver, 1.21% lead, and 14.82% zinc from 104.30 m depth, at an elevation of -11 m.
  • Hole 20CK11808 intersected a 0.56 m interval (0.38 m true width) of vein V18-4 grading 533 g/t silver, 2.98% lead, and 7.51% zinc from 104.05 m depth, at an elevation of 24 m.

 

High-grade intercepts of newly discovered silver-lead-zinc veins south of the resource area:

  • Hole 20CK46A01 intersected a 0.87 m interval (0.46 m true width) of vein V33-2 grading 994 g/t silver, 5.18% lead, and 5.52% zinc from 57.56 m depth, at an elevation of 149 m. The hole also intersected a 0.74 m interval (0.56 m true width) of vein V33-1 grading 447 g/t silver, 2.04% lead, and 5.28% zinc from 72.76 m depth, at an elevation of 146 m
  • Hole 21CK4820 intersected a 2.16 m interval (1.30 m true width) of vein V35 grading 539 g/t silver, 8.06% lead, and 3.23% zinc from 47.55 m depth, at an elevation of 140 m.

 

High-grade intercepts of newly discovered silver-lead-zinc veins north of the resource area:

  • Hole 20CK4802 intersected a 0.47 m interval (0.46 m true width) of vein NV6 grading 115 g/t silver, 0.54% lead, and 18.05% zinc from 135.29 m depth, at an elevation of 39 m.

 

Mineral Resources:

The estimated Mineral Resources and metal content for the property as of June 30, 2024 are detailed in the table below.

Gaocheng Property - Measured & Indicated, and Inferred Mineral Resources

(Inclusive of Mineral Reserves)

RESOURCE CLASSIFICATION TONNES (Mt) Ag (g/t) Pb (%) Zn (%) CONTAINED METAL
Ag (koz) Pb (kt) Zn (kt)
MEASURED 5.87 88 1.30 3.11 16,542 76 183
INDICATED 5.62 80 1.05 2.57 14,507 59 144
MEASURED AND INDICATED 11.49 84 1.18 2.85 31,049 136 327
INFERRED 9.57 85 1.23 2.44 26,194 117 234

Notes:

  • Mineral Resource Statement as of June 30, 2024.
  • The cut-off grade estimates are based on the forecast prices 25 USD/oz silver, 2,600 USD/t lead, and 3,300 USD/t zinc.
  • AgEq = Ag+44.83*Pb+40.02*Zn.
  • Mineral Resource are reported at a cut-off grade of 120 g/t AgEq.
  • The veins within the depth less than 5m below surface are not included in the Mineral Resource.
  • The totals may not compute exactly due to rounding.
  • The Mineral Resource estimates for the GC Mine were carried out by Silvercorp and reviewed and approved by independent Qualified Person, Mark Wanless, Sci,Nat, FGSSA of SRK Consulting (South Africa) Ltd., who takes responsibility for these estimates.

Mineral Reserves:

The estimated Mineral Reserves and metal content for the property as of June 30, 2024 are detailed in the table below.

Gaocheng Property - Proven and Probable Mineral Reserves

RESERVE CLASSIFICATION Tonnes (Mt) Ag (g/t) Pb (%) Zn (%) CONTAINED METAL
Ag (koz) Pb (kt) Zn (kt)
PROVEN 2.73 81 1.26 2.95 7,142 34 81
PROBABLE 2.23 81 1.15 2.71 5,791 26 61
PROVEN + PROBABLE 4.97 81 1.21 2.84 12,933 60 141

Notes:

  • Mineral Resource Statement as of June 30, 2024.
  • The cut-off grade estimates are based on the forecast prices 22 USD/oz silver, 2,050 USD/t lead, and 2,650 USD/t zinc.
  • AgEq = Ag+44.83*Pb+40.02*Zn.
  • 150 g/t AgEq and 200 g/t AgEq COG was applied to shrinkage and resuing type stopes, respectively.
  • The Mineral Reserves are reported on a metric dry tonne basis.
  • The Mineral Reserves are reported at the reference point of ROM stockpile before crushing or directly crushing.
  • The totals may not compute exactly due to rounding.
  • The Mineral Reserve estimates for the GC Mine were carried out by Silvercorp and reviewed and approved by independent Qualified Person, Falong Hu, FAusIMM of SRK Consulting (China) Ltd., who takes responsibility for these estimates.

Geological Background

The GC property is located on the east margin of the Luoding basin, within the north portion of the Yunkai uplift of the South China Orogenic Belt, at the intersection between the Wuchuan-Sihui Deep Fault zone and Daganshan Arc-ring structural zone. Basement rocks within the project area consist of sedimentary clastics and carbonates belonging to the Sinian Daganshan Formation, the Triassic Xiaoyunwushan Formation, and the Cretaceous Luoding Formation. These rocks are intruded by Palaeozoic medium-grained biotite granite and Mesozoic fine- to medium-grained adamellite, brownish, fine-grained, biotite mylonite, granite porphyry, quartz porphyry, diabase, and aplite. The Mesozoic units intruded along the south and southwest contacts of the Palaeozoic granites. The majority of silver-zinc-lead mineralization is hosted by the Mesozoic granite, which dips south and strikes approximately WNW, parallel to many of the mineralized veins on the property.

 

GC is a mesothermal vein deposit hosted within a WNW-ENE trending, 4.8 km long by 2 km wide fault zone. The zone contains numerous variably oriented veins, including:

  • The more common WNW veins with 90-150° strike and 55° to sub-vertical drip. The average vein thickness is 0.76 m.
  • East-west veins with 50-130° strike and 65° to sub-vertical drip. The average vein thickness is 0.77 m.
  • Veins sub-parallel to the major NE striking faults F25 and F27, with 10-80° strike and 60-75° dip. The average vein thickness is 0.76 m.

 

Primary silver-zinc-lead mineralization represents 95% of GC’s current Mineral Resources. Pyrite is the dominant sulphide species, typically comprising up to 13% of the vein. Other metallic constituents include:

  • A few percent of sphalerite, galena, pyrrhotite, arsenopyrite and magnetite.
  • Less than one percent of chalcopyrite and cassiterite.
  • Trace amount of argentite, native silver, bornite, wolframite, scheelite and antimonite.

 

Metallic minerals occur in narrow massive bands, veinlets and as disseminations in gangues.

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