NEXA ANNOUNCES 2022 YEAR-END

MINERAL RESERVES AND MINERAL RESOURCES

Luxembourg, March 20, 2023 - Nexa Resources S.A. ("Nexa Resources" or "Nexa" or the "Company") (NYSE Symbol: "NEXA") announces its 2022 Year-End Mineral Reserves and Mineral Resources ("MRMR") relating to its operations and projects located in Peru and Brazil.

Commenting on the MRMR update, Ignacio Rosado, CEO of Nexa Resources, said "Our mineral exploration program in 2022 was focused on identifying new ore bodies in our operating mines including Aripuanã, where significant results from the Ambrex infill drilling program increased the mine life by three years.

As a major polymetallic and the 5th largest zinc producer worldwide, Nexa has a unique portfolio of operating mines with excellent exploration potential and a pipeline of greenfield exploration projects. In 2023, our mineral exploration program will remain focused on the replacement of Mineral Reserves and upgrading Mineral Resources through infill drilling campaigns."

2022 Year-End Mineral Reserves and Mineral Resources Highlights

Mineral Reserves

Note: "Addition" refers to new tonnages from brownfield and infill drilling and "Revision" refers to changes in Mineral Reserves due to changes in mine design, changes in economic parameters, leading to a model review and update. Reserve numbers refer to Zinc mines and projects.

  • As of December 31, 2022, Proven and Probable Mineral Reserves estimates amounted to 100.6 million tonnes containing 3,540kt of zinc compared with 97.1 million tonnes containing 3,359kt of zinc as of December 31, 2021. The increase was mainly driven by infill and brownfield drilling at Aripuanã, partially offset by mining production depletion. Nexa's 2022 Year-End Mineral Reserves estimate also reflects changes in continuous refining of its geological modelling.
  • The net revision of 120kt zinc was primarily due to the reduction of geotechnical restrictions at Cerro Lindo (65kt) and model updates at Vazante (41kt), and El Porvenir (14kt).
  • The Proven and Probable Mineral Reserves at Cerro Lindo were estimated to total 41.43Mt at 1.57% Zn, 0.22% Pb, 0.59% Cu and 22.5 g/t Ag as of December 31, 2022, a 6% decrease from 44.0Mt at 1.43% Zn, 0.20% Pb, 0.62% Cu and 22.3 g/t Ag as of December 31, 2021. The decrease was the result of mining production depletion during 2022, balanced by the reduction of operational

geotechnical restrictions. Mineral Reserve depletion during 2022 accounted for -4.89Mt containing 70.4kt of zinc.

  • The Proven and Probable Mineral Reserves at Vazante were estimated to total 13.50Mt at 9.64% Zn, 0.27% Pb, and 15.2 g/t Ag as of December 31, 2022, down 15% from 15.91Mt at 8.77% Zn, 0.22% Pb and 13.7 g/t Ag as of December 31, 2021. The decrease was the result of mining production depletion during 2022, which was partially replaced by drilling and updates in Extremo Norte, Sucuri Norte and Lumiadeira areas. Mineral Reserve depletion during 2022 accounted for - 1.41Mt containing 134kt of zinc. Another 1.0Mt decrease is due to a more selective mine plan with lower dilution that improved head grades and financial returns.
  • The Proven and Probable Mineral Reserves at El Porvenir were estimated to total 15.50Mt at 3.60% Zn, 1.07% Pb, 0.19% Cu and 66.0 g/t Ag as of December 31, 2022, a 3% decrease from 15.91Mt at 3.57% Zn, 1.04% Pb, 0.20% Cu and 69.5 g/t Ag as of December 31, 2021. The decrease is mainly the result of mining depletion, partially offset by the addition of 56kt of zinc from infill drilling at known orebodies extensions. Mineral Reserve depletion during 2022 accounted for -2.10Mt containing 59.6kt of zinc.
  • The Proven and Probable Mineral Reserves at the Aripuanã project were estimated to total 30.12Mt at 3.42% Zn, 1.25% Pb, 0.17% Cu, 32.1 g/t Ag and 0.23 g/t Au as of December 31, 2022, a 38% increase from 21.79Mt at 3.61% Zn, 1.36% Pb, 0.23% Cu, 33.5 g/t Ag and 0.30 g/t Au as of December 31, 2021. The increase of 254kt of zinc in the reserves was due to the Ambrex infill drilling program carried out during 2022. Mineral Reserve depletion during 2022 accounted for - 0.45Mt containing 10.5kt of zinc, resulting in a net increase of 243kt of contained zinc.

Mineral Resources

Note: "Addition" refers to new tonnages from brownfield and greenfield drilling and "Revision" refers to changes in Mineral Resources due to changes in reclassification, mine design, changes in economic parameters, leading to a model review and update. Mineral Resource numbers refer to Zinc mines and projects. After a careful assessment and prioritization of our exploration project portfolio, we have decided to not move forward with certain projects, including Caçapava do Sul, located in Brazil, as well as Pukaqaqa and Shalipayco, located in Peru. As a result, 2021 Mineral Resources was updated to maintain the same comparative basis as the 2022 data.

  • As of December 31, 2022, Nexa estimated Measured and Indicated Mineral Resources (exclusive of mineral Reserves) were 3,432kt of contained zinc compared with 3,840kt as of December 31, 2021.

2

The Addition and Revision accounted for a net decrease of -408kt of contained zinc mostly due to model reclassification revision.

  • The addition from brownfield drilling accounted for 53kt of contained zinc at Hilarión South, and the model revision at Hilarión reduced -412kt of contained zinc in Mineral Resource reclassification to the Inferred Mineral Resource category. At Vazante Aroeira tailings, a block model update resulted in reclassification from Inferred Mineral Resource to Indicated Mineral Resource category, accounting for an increase of 108kt of contained zinc in the Indicated Mineral Resources. At Atacocha underground a topographic revision accounted for a -72kt reduction in contained zinc.
  • As of December 31, 2022, Nexa estimated Inferred Mineral Resources of 6,626kt of contained zinc, compared with the total of 5,905kt at the end of 2021. The addition of 517kt of contained zinc was incorporated through exploration and infill drilling. The net revision increases of 204kt of contained zinc is mostly due to model revisions and reclassification.
  • Notable additions from exploration drilling to Inferred Mineral Resources included:
    • 408kt from Vazante brownfield, including 318kt from BDMG acquisition;
    • 446kt from Hilarión South;
    • -422ktfrom Aripuanã mostly due to conversion to Probable Mineral Reserves.

A total of 374kt of contained zinc was added to the Inferred Mineral Resource category at the Hilarión project as a result of Mineral Resource reclassification from Measured and Indicated Mineral Resources. There was a decrease in Inferred Mineral Resources of -102kt from reclassification at Vazante Aroeira due to a reclassification to Measured and Indicated Mineral Resources.

Exploration Outlook

Nexa's exploration strategy for 2023 will remain focused on Mineral Resource expansion through brownfield and infill drilling near operating mines and extension drilling on advanced projects.

A total of 78,185 meters of drilling is planned for 2023, including 45,000 meters in Peru (57%), 25,685 meters in Brazil (33%) and the remaining 7,500 meters in Namibia (10%).

At Cerro Lindo, we plan to drill a total of 32,000 meters including extension drilling at Pucasalla, Puca Punta, Mesa Rumi and Festejo targets, located in the northern side of the Cerro Lindo mine and Orebody 8B, located southeast of known mineralized bodies of the mine. At El Porvenir, we plan to drill 6,000 meters at the Integración target to extend the mineralized hydrothermal breccia to upper levels of the deposit. At Hilarión, we plan to drill 3,000 meters within two targets: El Padrino in the northwestern part of the Hilarión deposit and Chaupijanca to the southeast aiming to test a potential copper mineralization system and extend zinc mineralization in those areas. We will resume our drilling campaigns in Florida Canyon, with an expected 4,000 meters of drilling focused on expanding the Florida Canyon mineralization to the South on Florida Sur target.

At Aripuanã, the strategy is to drill 4,400 meters to extend the Babaçu body to the northwest and to test the mineralization gap between Link and Ambrex. An additional 11,200 meters of infill drilling is planned for Mineral Resources reclassification at Babaçu. At Vazante, we plan to carry out 10,085 meters of brownfield drilling at known orebody extensions.

In Namibia, we plan to drill 7,500 meters to continue investigating copper mineralization in Namibia North along the Deblin and Tsumeb trends.

3

We expect to continue advancing our drilling campaigns and developing our pipeline of projects, prioritizing belts for exploratory drilling and Mineral Resource expansion to consolidate our Zinc and Copper portfolio with optimized investments between them.

Mineral Reserves and Mineral Resources Tables

MINERAL RESERVES

The following table shows our estimates of Mineral Reserves prepared with an effective date of December 31, 2022 (except as indicated below).

Table 2. Nexa Year-End Mineral Reserves as of December 31, 2022 (except as indicated below) for Zinc operating mines.

NOTES TO MINERAL RESERVES TABLE

Mineral Reserves are expressed on a 100% basis. The Qualified Persons for the estimation of the Mineral Reserves for Cerro Lindo is Cristovao Teofilo dos Santos, B.Eng., a Nexa employee, El Porvenir and Vazante is Vitor Marcos Teixeira de Aguilar, B.Eng., a Nexa employee, and for Aripuanã is SLR Consulting (Canada) Ltd.

Mineral Reserves have an effective date of December 31, 2022, for Cerro Lindo, El Porvenir, Vazante and Aripuanã mines.

2014 CIM Definition Standards were followed for Mineral Reserves, which are consistent with definitions used under Subpart 1300 of Regulation S-K.

Mineral Reserves are reported within engineered stope outlines assuming the following underground mining methods: El Porvenir and Vazante - SLS and C&F; Cerro Lindo - SLS; and Aripuanã - longitudinal longhole retreat (bench stopping) and transverse longhole mining (VRM). Dilution and mining recovery are considered.

At Cerro Lindo, Mineral Reserves are estimated at an NSR break-evencut-off value of US$42.65/t processed. Some incremental material with values between US$35.14/t and US$38.84/t was included.

4

At El Porvenir Mineral Reserves are estimated at NSR break-evencut-off values ranging from US$57.99/t to US$62.37/t depending on the zone and mining method. At Vazante Mineral Reserves are estimated at NSR break-evencut-off value of US$60.61/t. At Aripuanã Mineral Reserves are estimated at an NSR break-evencut-off value of US$48.11/t processed. Some incremental material with values between US$38.05/t and US$47.91/t was included.

Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Forecast long-term metal prices used for the NSR calculation are Zn: US$2,826.35/t (US$1.28/lb); Pb: US$2,043.95/t (US$0.93/lb); Cu: US$7,398.47/t (US$3.36/lb); Ag: US$19.93/oz, and Au: US$1,474.88/oz for Aripuanã.

For Vazante and Aripuanã, a 4.0 m minimum mining width was applied. For Cerro Lindo and for El Porvenir a minimum mining width of 5.0 m was applied. Bulk density at Cerro Lindo and Aripuanã varies depending on mineralization domain. At Vazante the default density is 2.8 t/m³ and El Porvenir is 2.94 t/m³.

Numbers may not add due to rounding.

5

Attachments

  • Original Link
  • Original Document
  • Permalink

Disclaimer

Nexa Resources SA published this content on 20 March 2023 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 20 March 2023 20:50:12 UTC.