Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Production Start | ...  |
Mine Life | 2025 |
At San Bartolomé, Andean produces silver primarily through contracts with the state-owned mining company, Corporación Minera de Bolivia (“COMIBOL”).
Andean also maintains various agreements to purchase oxidized, precious metal-bearing material from local miners based on market rates for processing at the San Bartolomé plant.
Material processing takes place at the Company’s San Bartolomé plant, which is the only largescale commercial oxide plant in Bolivia. The San Bartolomé plant produces silver doré bars. |
Source:
p. 10
The Company owns a 100% interest in, through direct and indirect interests, Empresa Minera Manquiri S.A. ("Manquiri") which is the operator of the San Bartolomé mine and processing facility, near Potosì, Bolivia. The Company is engaged in the exploration, exploitation, treatment, refining and commercialization of doré containing silver and gold, which it extracts from its own mining rights and though purchased third-party material.
Andean extracts material in partnership with the state-owned mining company, COMIBOL. Pursuant to a production agreement, the Company currently pays production royalties to COMIBOL in return for the rights to mine, transport and process mineralized pallacos from the Santa Rita, Huacajchi and Antuco sectors.
Contractors
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Deposit Type
- Tailings
- Vein / narrow vein
- Breccia pipe / Stockwork
- Alluvial / Placer
Summary:
The mineral deposits at San Bartolomé are alluvial and colluvial, surficial accumulations of silver- and tinbearing unconsolidated material, which were derived from erosion of Cerro Rico, a prominent +4,700 meter elevation mountain, and accumulated down-slope filling depressions, gullies and low-gradient areas. Locally they are called “pallacos” which also includes reworked Sn-bearing gravel deposits called “sucus” and “troceras”. Mineral deposits at Tatasi-Portugalete are man-made, dumps adjacent to underground mine portals of ancient and current mines.
San Bartolomé
The mineral deposits at Cerro Rico are the source of the San Bartolomé pallacos and are high sulfidation epithermal in character, composed of veins, stockworks, hydrothermal breccias and irregular bodies, hosted in a very altered resurgent dome of dacitic- to rhyodacitic-composition porphyritic intrusion emplaced in Middle Miocene time (approx. 14 mya). The pallacos were derived from the erosion of the Cerro Rico hydrothermal ore deposit and were emplaced around the mountain crest by recent geologic processes. These deposits consist of an unsorted mixture of cobbles and boulders in a sandy clay matrix, accumulated down slope by colluvial and alluvial processes, filling depressions, gullies and low-gradient areas. They cover an area of over 5 km2 in size. Geologically, the true thicknesses of the pallacos range from <1 m to nearly 75 m. The deposits have been grouped into three areas named Antuco ........

Summary:
Ore is mined from the Company’s permitted mineral reserve areas:
- The San Bartolomé mine (“pallacos”).
- Dump areas at Tatasi-Portugalete and El Asiento.
The project utilizes conventional surface mining methods to extract colluvial, and alluvial materials mine dumps, oxide and sulfide tailings and other materials named pallacos and sucus and troceras (collectively, the “pallacos”), which have been identified in the Huacajchi, Santa Rita, Diablo (Norte and Sureste areas – now referred to as Antuco) - Pallacos Areas.
An exclusive mineral purchase contract is in place between Manquiri and RALP Compañía Minera, S.R.L., a private, Bolivian mining company (“RALP”). The contractual rights held by Manquiri are for processing of 108,000 tonnes of silver- and gold-bearing material being mined by RALP.
The current mine plan is designed with 5 m benches and 2 m berms. Additional 5 m wide safety berms were included in the design when the slope height exceeds 25 m.
Dump areas at Tatasi-Portugalete and El Asiento will be fully reclaimed in 2 m slices in a top-down sequence. If internal operational slopes are required, the angle of repose of 37° will be considered.
The mining strategy adopted by Manquiri is a mixed between an owner operation and contracted:
• In the pallacos areas Manquiri operates the loading with owned excavators of 2.4 / 2.6 m3 and auxiliary operations (bulldozers and motor graders) and the hauling o ........

Source:

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Flow Sheet:
Summary:

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Reserves at December 31, 2022:
Pallacos mineral resources are reported using the following Ag cut-off Grades: Antuco: 62.9 g/t Ag, Huacajchi: 58.1 g/t Ag and Santa Rita: 61.5 g/t Ag.
A nominal cut-off of US$25/t has been used for reporting the Tailings mineral resource.
A nominal cut-off of US$25.00 per tonne has been used for reporting the mineral resources at the Stockpiles.
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Measured & Indicated
|
|
2.319 Mt
|
Silver
|
91 g/t
|
6.77 M oz
|
Measured & Indicated
|
Stockpiles
|
10.148 Mt
|
Silver
|
50 g/t
|
16.2 M oz
|
Measured & Indicated
|
Stockpiles
|
10.148 Mt
|
Tin
|
0.12 %
|
11.93 kt
|
Inferred
|
|
0.347 Mt
|
Silver
|
97 g/t
|
1.09 M oz
|
Inferred
|
Stockpiles
|
1.505 Mt
|
Silver
|
48 g/t
|
2.3 M oz
|
Inferred
|
Tailings
|
18.11 Mt
|
Silver
|
43 g/t
|
25.09 M oz
|
Inferred
|
Stockpiles
|
1.505 Mt
|
Tin
|
0.09 %
|
1.33 kt
|
Inferred
|
Tailings
|
18.11 Mt
|
Tin
|
0.16 %
|
28.9 kt
|
Source:

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Corporate Filings & Presentations:
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