Overview
| Stage | Production |
| Mine Type | Underground |
| Commodities |
|
| Mining Method |
- Sub-level open stoping (SLOS)
- Longhole stoping
- Vertical Crater Retreat
- Dry waste backfill
|
| Production Start | ...  |
| Mine Life | 2032 |
The Vazante Operation consists of two mechanized underground mines, the Vazante Mine and Extremo Norte Mine. There are former open pits along portions of the strike of the Vazante deposit. |
Source:
p. 40, 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 Vazante project.
Contractors
- Subscription is required.
Deposit Type
- Hydrothermal
- Carbonate hosted
- Vein / narrow vein
Summary:
The geology of the Vazante Operation area consists of a sequence of pelitic carbonate rocks belonging to the Serra de Garrote and Serra do Poço Verde formations of the Vazante Group. The currently known mineralization has been traced along a strike length of approximately 10.5 km, extending from the southern end of the Vazante Mine to the northern limits of the Extremo Norte Mine.
MINERALIZATION
The zinc-lead-silver mineralization at the Vazante Operation is hosted by the Vazante Shear Zone which has been traced by drilling and sampling along a strike length of approximately 12 km. The Vazante Shear Zone has a general strike of azimuth 50° and dips approximately 60° to the northwest at surface. The hanging wall lithologies of the Vazante Shear Zone are comprised of dolostone and sericitic phyllite, slates and marl units of the Serra do Poço Verde Formation while the footwall lithologies to the Vazante Shear Zone are dominated by dark grey dolostones of the Upper Morro do Pinheiro Member. Drilling information indicates that the dip of the zinc mineralized zone gradually decreases with depth in the southern portions of the structure.
The zinc mineralization at the Vazante and Extremo Norte mines is composed largely of hypogene zones that are composed mainly of willemite (Zn2SiO4) veins, veinlets, and stockworks that are hosted by sphalerite-rich carbonate. The mineralization typically contains willemite (50% to 70%), dolomite (10% to 30%), siderite ........
Mining Methods
- Sub-level open stoping (SLOS)
- Longhole stoping
- Vertical Crater Retreat
- Dry waste backfill
Summary:
MINE DESIGN
The Vazante Operation consists of two mechanized underground mines, the Vazante Mine and Extremo Norte Mine, currently operating at a rate of approximately 1.5 Mtpa. The mineralized zones dip between 45° and 70° and the mine extends over a strike length of five kilometres. With the addition of the North Extension, this will increase to approximately 10 km. The Vazante Mine currently extends over a vertical depth of 300 m from surface to the 326 level. The Vazante Mine is being deepened by 186 m to the planned 140 level. There are former open pits along portions of the strike of the Vazante deposit.
There are two access ramps to the Vazante Mine and one to the Extremo Norte Mine. Mine headings range from 5.0 m high by 4.5 m wide ore drives to 6.0 m high by 5.0 m wide main ramps.
The Vazante Operation is designed based upon mechanized longitudinal longhole stoping for areas with a dip greater than 45°. Longhole stopes are developed with footwall access drives parallel to the orebody. Crosscuts are driven from the footwall drive and then the ore is developed along strike. Sublevels are typically 30 m apart though the distance varies depending on the orebody. Long holes are often a combination of downholes or vertical retreat mining (VRM) and uppers or sublevel longhole open stopes (SLOS). Both longhole methods employ a retreat sequence along strike. The SLOS stopes are not backfilled whereas the VRM stopes are backfilled.
Backf ........
Source:
- subscription is required.
Flow Sheet:
Summary:
- subscription is required.
Production:
| Commodity | Product | Units | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
|
Zinc
|
Metal in concentrate
|
t
| ...... ^ | ...... | ...... | ...... | 140,842 | 135,379 | 135,509 |
|
Lead
|
Metal in concentrate
|
t
| ...... ^ | ...... | ...... | ...... | ...... | ...... | ...... |
|
Silver
|
Metal in lead concentrate
|
oz
| ...... ^ | ...... | ...... | ...... | ...... | ...... | ...... |
|
Zinc Equivalent
|
Metal in concentrate
|
t
| | ...... | ...... | ...... | ...... | ...... | ...... |
|
Zinc
|
Concentrate
|
kt
| | | | | 357 | 349 | 344 |
|
Lead
|
Concentrate
|
kt
| | | | | ...... | ...... | ...... |
^ Guidance / Forecast.
- Subscription is required.
Operational Metrics:
| Metrics | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
|
Tonnes processed
| ...... | ...... | 1,407,199 t | 1,374,380 t | 1,321,240 t | 1,381,301 t |
|
Daily processing capacity
| ...... | ...... | 4,100 t | 4,100 t | 4,100 t | |
|
Annual processing capacity
| ...... | ...... | | | | |
- Subscription is required.
Reserves at December 31, 2021:
Mineral Reserves are estimated at a cut-off grade of 4% Zn. Mineral Reserves are estimated using average LOM metal prices of Zn: US2,722.20/t (US$1.23/lb), Pb: US$1,997.21/t (US$0.91/lb) and US$19.68/oz Ag.
Mineral Resources are estimated at various NSR cut-off values appropriate to the mineralization style and mining method. For Supergene Mineralization (Calamine) the resources are estimated at a NSR cut-off value of US$20.33/t for soil and US$22.18/t for fresh rock and transition material. For Aroeira Tailings the resources are estimated ate a NSR cut-off value of US$20.62/t and for Hypogene Mineralization (Willeminte) a cut-off value of US$ 52.95/t for all resources shapes. Forecast long-term metal prices used for the NSR calculation are: Zn: US$3,130.52/t (US$1.42/lb), Pb: US$2,296.79/t (US$1.04/lb); and Ag: US$22.63/oz.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Proven & Probable
|
15.91 Mt
|
Zinc
|
8.77 %
|
1,395 kt
|
|
Proven & Probable
|
15.91 Mt
|
Lead
|
0.22 %
|
35.3 kt
|
|
Proven & Probable
|
15.91 Mt
|
Silver
|
13.7 g/t
|
6,992 koz
|
|
Measured & Indicated
|
5.28 Mt
|
Zinc
|
4.69 %
|
247.6 kt
|
|
Measured & Indicated
|
5.28 Mt
|
Lead
|
0.09 %
|
4.9 kt
|
|
Measured & Indicated
|
5.28 Mt
|
Silver
|
4.7 g/t
|
777 koz
|
|
Inferred
|
15.44 Mt
|
Zinc
|
7.72 %
|
1,192 kt
|
|
Inferred
|
15.44 Mt
|
Lead
|
0.19 %
|
30 kt
|
|
Inferred
|
15.44 Mt
|
Silver
|
11.2 g/t
|
5,395 koz
|
- Subscription is required.