Overview
Stage | Production |
Mine Type | Open Pit / Underground |
Commodities |
- Silver
- Gold
- Copper
- Zinc
- Lead
- Lead-Silver
|
Mining Method |
- Truck & Shovel / Loader
- Sub-level stoping
|
Processing |
|
Source:
p. 60
The Colquijirca (also known as Tajo Norte) and Marcapunta Norte mines are wholly-owned by El Brocal. Compania de Minas Buenaventura S.A.A aggregate direct and indirect equity interest in El Brocal was 61.43% at December 31, 2018.
Summary:
The Colquijirca mine consists of three important polymetallic deposits: (1) Tajo NorteāSmelter, which contains zinc, silver and lead; (2) Marcapunta, which contains an auriferous mineralization in breccia oxides and an arsenic copper enargite mineralization as a continuation of the mineralized mantles of the Marcapunta Norte mine; and (3) San Gregorio massive zinc deposit, which contains zinc.
San Gregorio is located four kilometers south of the Colquijirca mine and consists of carbonate-hosted epithermal zinc-lead deposits.
The Colquijirca deposit (Tajo Norte) is structurally located within asymmetric synclines and anticlines, whose flanks are Principal-Mercedes-Chocayoc-La Llave-La Pampa; and stratigraphically located in the Calera Formation (Lower Tertiary-Eocene), middle and upper members. The base metal zone (Zn + Pb-Ag) is the outermost halo of mineralization (cordillera-type) and, by volume, the zone of greatest economic importance. Its mineralogy consists of sphalerite and galena as vein ores, which occur as fracture filling and cavities, disseminations, and massive replacements. The gangue consists of pyrite, specular hematite, magnetite, kaolin, barite, siderite, ankerite-dolomite, and fluorite, less commonly. All of them occur as fracture filling and cavities. Native silver as filigree in cavities, and in association with siderite, has been observed near the transition zone. It is also possible to observe the occurrence of chalcopyrite-galena-dickite as filling in fractures and replacement zones.
At Marcapunta Norte, mineralization is stratiform, in both the mineralized blankets emplaced in the limestone of the Calera Medio Formation, and in the mineralized breccia located in the unit below said formation. The vein of ore consists of a massive replacement of sulfides and the filling of open spaces, for which reason it has been classified as a cordillera deposit tied to the Marcapunta volcanic complex. Mineralization consists of a vein of arsenical copper (enargite) with Ag-Au values, with gangues of pyrite, quartz, and alunite.
Mining Methods
- Truck & Shovel / Loader
- Sub-level stoping
Summary:
The Colquijirca (also known as Tajo Norte) and Marcapunta Norte mines are wholly-owned by El Brocal.
Tajo Norte is an open pit operation that exploits zinc-lead-silver ores.
The drills make boreholes measuring 6.5 m deep and 6.74 m in diameter, in a 5 x 5 m grid. Once the terrain has been drilled, the explosives are placed, carrying out the blasting process to stir up the rock. An excavator allows for better selectivity of the ore to be transported to the concentrating plant, 8 km away, using dump trucks with a 35-MT payload. For loading, a power shovel with a bucket capacity of 10 m3 is used. The barren material is transported to the waste or waste ore deposit located 1.8 km away, using trucks with a 50-MT payload.
Marcapunta is an underground operation that exploits arsenical copper ore.
The Marcapunta mining method involves long drills, by sub-levels.
Source:
Summary:
The ore from Marcapunta is treated in Plant 1, which uses the selective flotation process to achieve the concentration of the economic Cu mineralization. The concentrating plant is located in the Community of Huaraucaca, and includes the crushing, sorting, milling, conditioning, flotation, and filtering processes, as well as the respective tailings storage yards. Given the equipment characteristics and layout, the plant has the ability to beneficiate the copper ore from the Marcapunta Norte Mine. It has direct access to a railway, which is used to transport the concentrates to the port of El Callao.
The ore from Tajo Norte is treated at Plant 2, which uses the selective flotation process to achieve the concentration of the economic mineralization. It includes the crushing, washing, sorting, milling, conditioning, flotation, and filtering processes, as well as the respective tailings storage yards. Given the equipment characteristics and layout, the plant has the ability to b ........

Recoveries & Grades:
Commodity | Parameter | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
Recovery Rate, %
| ......  | ......  | 49.9 | 58.9 | 50.9 |
Gold
|
Head Grade, g/t
| ......  | ......  | 0.56 | 0.53 | 0.31 |
Copper
|
Recovery Rate, %
| ......  | ......  | 93.6 | 90.4 | 85.2 |
Copper
|
Head Grade, %
| ......  | ......  | 1.91 | 2.07 | 1.92 |
Zinc
|
Recovery Rate, %
| ......  | ......  | 59.3 | 61.1 | 62 |
Zinc
|
Head Grade, %
| ......  | ......  | 2.74 | 2.67 | 2.77 |
Lead
|
Recovery Rate, %
| ......  | ......  | 56.7 | 47.6 | 58.7 |
Lead
|
Head Grade, g/t
| ......  | ......  | 1.13 | 0.77 | 1.03 |
Production:
Commodity | Product | Units | 2019 | 2018 | 2017 | 2016 | 2015 |
Silver
|
Metal in concentrate
|
oz
| ......  | 3,901,869 | 4,084,249 | 2,634,739 | 3,669,500 |
Gold
|
Metal in concentrate
|
oz
| ......  | ......  | ......  | ......  | ......  |
Copper
|
Metal in concentrate
|
t
| ......  | ......  | ......  | ......  | ......  |
Copper
|
Concentrate
|
kt
| ......  | ......  | | | |
Zinc
|
Metal in concentrate
|
t
| ......  | ......  | ......  | ......  | ......  |
Zinc
|
Concentrate
|
kt
| ......  | ......  | | | |
Lead
|
Metal in concentrate
|
t
| ......  | ......  | ......  | ......  | ......  |
Lead-Silver
|
Concentrate
|
kt
| ......  | ......  | | | |
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Operational Metrics:
Metrics | 2019 | 2018 | 2017 | 2016 | 2015 |
Ore tonnes mined
| ......  | ......  | 5,687,581 t | 6,111,885 t | 5,064,478 t |
Daily processing capacity
| ......  | ......  | 20,000 t | 18,000 t | |
Tonnes processed
| ......  | ......  | 5,687,581 t | 6,111,885 t | 5,064,478 t |
Daily processing rate
| ......  | ......  | | 16,700 t | |
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Reserves at December 31, 2019:
Category | Tonnage | Commodity | Grade | ContainedĀ Metal |
Proven & Probable
|
76,719 kt
|
Silver
|
34503 oz/t
|
805 koz
|
Proven & Probable
|
76,719 kt
|
Gold
|
1.11 oz/t
|
85,379 koz
|
Proven & Probable
|
61,963 kt
|
Copper
|
1.49 %
|
920 kt
|
Proven & Probable
|
14,756 kt
|
Zinc
|
2.52 %
|
371 kt
|
Proven & Probable
|
14,756 kt
|
Lead
|
1.17 %
|
173 kt
|
Total Resource
|
54,519 kt
|
Silver
|
0.028 oz/t
|
1,541 koz
|
Total Resource
|
145,002 kt
|
Gold
|
0.62 oz/t
|
89,950 koz
|
Total Resource
|
54,519 kt
|
Copper
|
1.26 %
|
685 kt
|
Total Resource
|
90,483 kt
|
Zinc
|
4.98 %
|
4,507 kt
|
Total Resource
|
90,483 kt
|
Lead
|
1.46 %
|
1,324 kt
|
Commodity Production Costs:
| Commodity | Units | 2019 | 2018 | 2017 | 2016 | 2015 |
Cash costs (sold)
|
Zinc
|
USD
|
......
|
1,569 / t
|
1,915 / t
|
1,808 / t
|
1,601 / t
|
Cash costs (sold)
|
Copper
|
USD
|
......
|
5,487 / t
|
5,119 / t
|
4,651 / t
|
5,322 / t
|
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Financials:
| Units | 2019 | 2018 | 2017 | 2016 | 2015 |
Capital expenditures
|
M USD
| ......  | 29.6 | 61.1 |
51.3
|
37.6
|
Revenue
|
M USD
| ......  | 333.56 | 322.65 |
230.61
|
171.29
|
Gross profit
|
M USD
| ......  | 37 | 68.3 |
-3.98
|
-33.26
|
Operating Income
|
M USD
| ......  | 36.5 | 25.8 |
-28.1
|
-66.52
|
Pre-tax Income
|
M USD
| ......  | 26.7 | 14.3 |
-40.67
|
-80.3
|
After-tax Income
|
M USD
| ......  | 7.57 | 10.4 |
-32.82
|
-76.19
|
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Corporate Filings & Presentations:
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