Overview
Stage | Production |
Mine Type | Underground |
Commodities |
- Silver
- Zinc
- Lead
- Silver Equivalent
|
Mining Method |
- Longhole stoping
- Shrinkage stoping
- Cut & Fill
- Undefined backfill
|
Production Start | ... |
Porco Mine Complex consists of: an underground mine, 1,400 tonnes per day process plant, a water treatment plant, a tailings storage facility, camp and support buildings, and produces zinc and lead concentrates. The Porco Mine has been active for nearly 500 years.
The focus for 2023 at Porco is to send higher-grade feed to the plant by using more selective mining techniques to minimize dilution. |
Source:
p. 3,4
On March 18, 2022, Santacruz Silver Mining Ltd. acquired 100% ownership of Sociedad Minera Illapa S.A. (“Illapa”) from Glencore plc. The producing Porco mine held under an association agreement with Corporación Minera de Bolivia (“COMIBOL”) a Bolivian state-owned (Illapa holds a 45% interest, and COMIBOL – 55%).
Santacruz Silver Mining Ltd. is the operator of the Illapa Business.
Contractors
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Deposit Type
- Epithermal
- Vein / narrow vein
Summary:
The Porco silver-zinc-tin deposit is located 35 km southwest of the Cerro Rico de Potosí deposit on the southeastern edge of the Los Frailes volcanic field. It was the first silver deposit discovered in Bolivia, with exploitation dating to pre-colonial times. The geology has been described by Sugaki et al. (1983), Cunningham et al. (1993, 1994a, b) and Jiménez et al. (1998).
The deposit is hosted by a north-south-elongated caldera that is 5.0 km x 3.0 km and formed at 12.0 ± 0.4 Ma with the eruption of the crystal-rich dacitic Porco Tuff. Well defined topographic walls of the caldera cut Ordovician phyllites and Cretaceous sandstones. The 12.1 ± 0.4 Ma Apo Porco stock (4,886 masl) occurs on the southern margin of the caldera. Mineralization is associated with the younger 8.6 ± 0.3 Ma Huayna Porco stock (4,528 masl) in the center of the caldera. Radial dykes, alteration and metals are zoned around the stock. To the north, the Porco Tuff is overlain by the ignimbrites of the Los Frailes Formation dated at 6 to 9 Ma.
Mineralization occurs in NNE to NE-trending veins that cut the Porco Tuff about 1 km east of the Huayna Porco stock. The deposit is zoned around the stock with cassiterite proximal to the stock and base metals, mainly sphalerite and galena, further away. The upper parts of the veins are silver-rich with pyrargyrite, acanthite and stephanite. The main structure is the San Antonio vein which strikes N10º - 30ºE and dips between 70º and 85º to the ........
Mining Methods
- Longhole stoping
- Shrinkage stoping
- Cut & Fill
- Undefined backfill
Summary:
The Porco deposit consists of multiple, relatively thin high-grade veins. The mining methods used vary according to the continuity, dip, and width of these veins. Mining methods employed include sublevel longhole stoping with backfill, shrinkage stoping, and some cut and fill.
In 2022, the mine produces about 15,000 tonnes of mineralized material, and 700 meters of total development per month. The mine is comprised of two production areas. Hundumiento uses long hole mechanized mining methods to exploit the deeper extension of the primary vein complex, and the Central zone which is conventionally mined with more selective shrinkage stoping.
The mine is separated into two main areas: Hundimiento and Central zones:
- “Hundimiento” is the more modern section of the mine and is developed mostly with trackless methods using an access ramp to move men and materials between levels. The mineralized zones are predominantly wider and steeper dipping thus, stoping is 85% AVOCA mining and 15% shrinkage. This area is completely isolated from the Central zone and trucks its mineralized material to surface via an access ramp; sublevels are driven on nominal 15 m spacing with sill drifts in vein driven 3.0 m x 3.0 m, an average of 7 stopes produces about 300 t/d of mineralized material. All waste rock stays in the mine as backfill; and
- “Central” is 100% conventional shrinkage mining. Mineralized material is hauled via rail on each active level to ........
Source:
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Flow Sheet:
Summary:
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Source:
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Reserves at December 31, 2021:
The resources have been reported at a Zinc Equivalent (ZnEq) cut-off grade 2%.
Mineral Resources are reported inclusive of Mineral Reserves.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven & Probable
|
0.3 Mt
|
Silver
|
85 g/t
|
0.8 M oz
|
Proven & Probable
|
0.3 Mt
|
Zinc
|
8.4 %
|
|
Proven & Probable
|
0.3 Mt
|
Lead
|
0.4 %
|
|
Proven & Probable
|
0.3 Mt
|
Silver Equivalent
|
378 g/t
|
3.6 M oz
|
Measured & Indicated
|
1.1 Mt
|
Silver
|
93 g/t
|
3.3 M oz
|
Measured & Indicated
|
1.1 Mt
|
Zinc
|
10.8 %
|
|
Measured & Indicated
|
1.1 Mt
|
Lead
|
0.7 %
|
|
Measured & Indicated
|
1.1 Mt
|
Silver Equivalent
|
475 g/t
|
16.8 M oz
|
Inferred
|
2.2 Mt
|
Silver
|
98 g/t
|
6.9 M oz
|
Inferred
|
2.2 Mt
|
Zinc
|
11.8 %
|
|
Inferred
|
2.2 Mt
|
Lead
|
0.8 %
|
|
Inferred
|
2.2 Mt
|
Silver Equivalent
|
516 g/t
|
36.5 M oz
|
Financials:
| Units | 2022 |
Capital expenditures
|
M USD
| ...... |
Revenue
|
M USD
| ...... |
Gross profit
|
M USD
| ...... |
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Mine Management:
Job Title | Name | Phone | Ref. Date |
.......................
|
.......................
|
...........
|
Aug 10, 2023
|
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