Overview
| Stage | Production |
| Mine Type | Underground |
| Commodities |
|
| Mining Method |
|
| Production Start | ...  |
| Mine Life | 2028 |
Source:
p. 51, 208
Nexa Recursos Minerais S.A. (previously known as Votorantim Metais Zinco S.A.), which is wholly owned by Nexa Resources S.A., owns 100.0% of the Morro Agudo project.
Contractors
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Deposit Type
- Mississippi Valley Type
- Carbonate hosted
Summary:
The mineralization at Morro Agudo and the Ambrosia Trend are considered to be examples of Irish-type Zn-Pb deposits hosted by carbonate rocks which are a subclass of Mississippi Valley Type deposits.
MORRO AGUDO MINE
The Morro Agudo zinc and lead deposit comprises a number of concordant stratabound sulphide bodies, non-concordant remobilized sulphide bodies, and intraformational dolarenites and breccias of the Morro do Calcário Formation.
Mineralization
The combined length of the known mineralized bodies is approximately 1,700 m, the width is about 1,200 m, and the bodies have a variable thickness with a maximum of about 10 m. Mineralization is bounded to the northwest by the Main Fault. The western limit has not yet been defined, but drilling has shown continuity of mineralization at depth. Drilling deeper than 1,000 m has shown continuity of mineralization at depth, but with thinner intercepts (1 to 5 m) and lower grades.
The mineralized bodies are separated from each other by waste intervals of stratified dolarenites at upper and intermediate levels, and by waste breccias at lower levels. Sulphide levels occur as concordant stratabound lenses in dolarenite, and subordinately in dolomitic and dolarenitic breccias, in addition to occurring as late tectonic structure fill (faults/fractures). These sulphide lenses are typically less than 4 m thick, and separated by barren intervals that range from a few centimetres to several metre ........
Summary:
The LOM is based on mill feed material including Inferred Mineral Resources to be sourced from the operating underground Morro Agudo Mine and Bonsucesso deposits that are assumed to be mined using underground mining methods.
The open pit Ambrosia Sul mine in Morro Agudo reached the end of its life of mine during the fourth quarter of 2020 and operations were suspended due to the uncertainties associated with the geological model of the area, safety considerations and a greater movement of ore compared to the original plan. Due to the mine closure, Nexa reviewed Ambrosia’s portfolio of assets and analyzed the possibility of using these assets in other operations, such as the Bonsucesso mine, which is currently in the feasibility study phase.
Morro Agudo Mine
The primary extraction method at the Morro Agudo Mine is inclined room-and-pillar. The mineralized zones are accessed via a ramp system. Backfill is in limited use at the Morro Agudo Mine and is specified on an operational basis depending upon the deposit geometry.
The Morro Agudo Mine is a mature operation, and staff has a well-developed understanding of the hydrogeology, geology, and mining methods required to safely extract the mineralization. Development and access profiles take advantage of the known hanging wall structural characteristics to minimize ground support requirements. Water inflows into the Morro Agudo Mine are not a major source of water volume to the mine.
Source:
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Flow Sheet:
Summary:
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Production:
| Commodity | Product | Units | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
|
Zinc
|
Metal in concentrate
|
t
| ...... ^ | ...... | ...... | ...... | 26,408 | 20,969 | 22,688 |
|
Lead
|
Metal in concentrate
|
t
| ...... ^ | ...... | ...... | ...... | ...... | ...... | ...... |
|
Silver
|
Metal in concentrate
|
oz
| | ...... | ...... | ...... | ...... | | |
|
Zinc Equivalent
|
Metal in concentrate
|
t
| | ...... | ...... | ...... | ...... | ...... | ...... |
|
Zinc
|
Concentrate
|
kt
| | | | | 65 | 53 | 58 |
|
Lead
|
Concentrate
|
kt
| | | | | ...... | ...... | ...... |
^ Guidance / Forecast.
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Operational Metrics:
| Metrics | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
|
Ore tonnes mined
| ...... | ...... | 1,046 kt | 1,009 kt | 1,059 kt | 1,020 kt |
|
Tonnes processed
| ...... | ...... | 1,168,396 t | 1,060,930 t | 1,054,692 t | 1,018,969 t |
|
Daily processing capacity
| ...... | ...... | 3,400 t | 3,400 t | 3,400 t | |
|
Waste
| ...... | ...... | 1,477 kt | 2,827 kt | 2,148 kt | 356.59 kt |
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Reserves at December 31, 2021:
The NSR cut-offs are calculated based on the LOM costs for each mine - Morro Agudo: US$ 39.20/t and Bonsucesso: US$ 47.10/t. Mineral resources are estimated using average long-term metal prices of Zn: US$3,130.52/t (US$1.42/lb) and Pb: US$2,296.79/t (US$1.04/lb); Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Indicated
|
13.92 Mt
|
Zinc
|
3.39 %
|
472.1 kt
|
|
Indicated
|
13.92 Mt
|
Lead
|
0.59 %
|
82.4 kt
|
|
Measured & Indicated
|
13.92 Mt
|
Zinc
|
3.39 %
|
472.1 kt
|
|
Measured & Indicated
|
13.92 Mt
|
Lead
|
0.59 %
|
82.4 kt
|
|
Inferred
|
4.4 Mt
|
Zinc
|
3.26 %
|
143.6 kt
|
|
Inferred
|
4.4 Mt
|
Lead
|
0.47 %
|
20.8 kt
|
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