In 2017, we designed a detailed process for the preparation of technical reports required for the declaration of our mineral reserves and mineral resources in all of our mines and greenfield projects, which were in accordance with the standards set forth in Canada’s National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) and the U.S. Securities and Exchange Commission (“SEC”) Industry Guide 7.
In October 2018, the Securities and Exchange Commission (“SEC”) adopted amendments to its current disclosure rules to modernize the mineral property disclosure requirements for mining registrants. The amendments include the adoption of a new subpart 1300 of regulation S-K (“S-K 1300”), which will govern disclosure for mining registrants (the “SEC Mining Modernization Rules”). The SEC Mining Modernization Rules replace the historical property disclosure requirements for mining registrants that were included in the SEC’s Industry Guide 7 and better align disclosure with international industry and regulatory practices, including the NI 43-101.
Nexa notes that it has voluntarily adopted the SEC’s new disclosure requirements for mining reserves and resources under S-K 1300 for the financial year ended December 31, 2020, which are required to be adopted by registrants in annual reports for the fiscal year beginning on or after January 1, 2021.
We are always working on the updated of our mineral reserves and mineral resources, as presented below. The technical reports, mining reports and press releases related to mineral reserves and mineral resources are available on www.sedar.com and www.sec.gov.
Mineral Reserves and Mineral Resources
Nexa Resources announced on March 20, 2023, the publication of updated information relating to mineral reserves and resources as of December 31, 2022. All Mineral Reserve and Mineral Resource estimates of the Company disclosed or referenced in this news release have been prepared in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definition Standards on Mineral Reserves and Mineral Resources dated May 10, 2014 (“2014 CIM Definition Standards”), whose definitions are incorporated by reference in NI 43-101, for the metals indicated per mine and project. Accordingly, such information may not be comparable to the information that is presented in our annual report on Form 20-F prepared in accordance with S-K 1300.
| Mineral Reserves – NI 43-101 | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grade | Contained Metal | ||||||||||||
|
Interest (1)
|
Ownership (%) |
Class
|
Tonnage | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |||
|
Cerro Lindo Mine (2) |
83.48% |
Proven | 26.40 | 1.75 | 0.64 | 21.0 | 0.21 | – | 462.2 | 169.9 | 17,843 | 56.0 | – |
| Probable | 15.03 | 1.26 | 0.50 | 25.1 | 0.23 | – | 188.7 | 74.7 | 12,144 | 35.0 | – | ||
| Subtotal | 41.43 | 1.57 | 0.59 | 22.5 | 0.22 | – | 650.9 | 244.76 | 29,987 | 91.0 | – | ||
|
El Porvenir Mine (3) |
83.48% |
Proven | 2.54 | 3.70 | 0.21 | 67.7 | 1.12 | – | 94.9 | 5.4 | 5,532 | 28.3 | – |
| Probable | 12.96 | 3.58 | 0.19 | 65.7 | 1.06 | – | 464.6 | 25.0 | 27,362 | 137.3 | – | ||
| Subtotal | 15.50 | 3.60 | 0.19 | 66.0 | 1.07 | – | 558.6 | 30.4 | 32,894 | 165.6 | – | ||
|
Vazante Mine (4) |
100% |
Proven | 6.82 | 9.98 | – | 18.0 | 0.30 | – | 680.6 | – | 3,949 | 20.5 | – |
| Probable | 6.68 | 9.30 | – | 12.4 | 0.23 | – | 621.2 | – | 2,670 | 15.4 | – | ||
| Subtotal | 13.50 | 9.64 | – | 15.2 | 0.27 | – | 1,301.8 | – | 6,619 | 35.9 | – | ||
|
Aripuanã Mine (5) |
100% |
Proven | 8.41 | 3.25 | 0.29 | 29.1 | 1.18 | 0.24 | 273.4 | 24.0 | 7,863 | 99.1 | 64.0 |
| Probable | 21.71 | 3.48 | 0.12 | 33.2 | 1.28 | 0.22 | 755.9 | 26.4 | 23,163 | 278.6 | 156.0 | ||
| Subtotal | 21.79 | 3.61 | 0.23 | 33.5 | 1.36 | 0.30 | 785.6 | 50.0 | 23,496 | 295.5 | 208.0 | ||
|
Total |
Proven | 44.17 | 3.42 | 0.45 | 24.8 | 0.46 | 0.05 | 1,510.2 | 199.3 | 35,187 | 203.9 | 64.0 | |
| Probable | 56.38 | 3.60 | 0.22 | 36.0 | 0.83 | 0.09 | 2,030.4 | 126.1 | 65,339 | 466.3 | 156.0 | ||
| Total | 100.55 | 3.52 | 0.32 | 31.1 | 0.67 | 0.07 | 3,540.6 | 325.4 | 100,526 | 670.2 | 220.0 | ||
Notes: The estimation of Mineral Reserves involves assumptions as to future commodity prices and as to technical mining matters. Numbers and totals may not sum due to rounding. The qualified person responsible for the Mineral Reserve estimates are not aware of any mining, metallurgical, infrastructure, permitting, or other relevant factors that could materially affect the Mineral Reserve estimate.
(1) The tonnage and content amounts presented in this table have not been adjusted to reflect our ownership interest. The information presented in this table includes 100% of the Mineral Reserves estimates of our consolidated subsidiaries and of our joint ventures, certain of which are not wholly owned, as set out in this ownership interests’ column.
(2) Cerro Lindo Mine
The Qualified Person for the Mineral Reserves estimate is Cristovao Teofilo dos Santos, B.Eng., FAusIMM, a Nexa Resources employee. Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. Mineral Reserves are estimated at an NSR break-even cut-off value of US$42.65/t processed. Some incremental material with values between US$35.14/t and US$42.65/t was included. Mineral Reserves are estimated using average long-term metal prices of 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); and Ag: US$19.93/oz. Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grades 88.72% for Zn, 66.75% for Pb, are 85.92% for Cu, and 68.8% for Ag. A minimum mining width of 5.0 m was used. Dilution and extraction factors are applied based on stope type and location. Bulk density varies depending on mineralization domain.
(3) El Porvenir Mine
The Qualified Person for the Mineral Reserves estimate is Vitor Marcos Teixeira de Aguilar, B.Eng., FAusIMM, a Nexa Resources employee. Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. The Mineral Reserves were estimated at a NSR cut-off values ranging from US$57.99/t to US$60.71/t for SLS areas and US$59.65/t to US$62.37 for C&F areas depending on the zone Mineral Reserves are estimated using average long-term metal prices of 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); and Ag: US$19.93/oz. Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the LOM average head grades are 88.85% for Zn, 79.73% for Pb, 11.81% for Cu, and 63.00% for Ag. A minimum mining width of 5.0 m was applied. Average Bulk density of 2.94 t/m3.
(4) Vazante Mine
The Qualified Person for the Mineral Reserves estimate is Vitor Marcos Teixeira de Aguilar, B.Eng., FAusIMM, a Nexa Resources employee. Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. Mineral Reserves are estimated at a NSR cut-off value of US$ 60.61/t processed. Mineral Reserves are estimated using average metal prices of Zn: US$2,826.35/t (US$1.28/lb); Pb: US$2,043.95/t (US$0.93/lb); and Ag: US$19.93/oz (using an average long term U.S. dollar to Brazilian real exchange rate of 4.96). Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the LOM average head grades are 87.20% for Zn, 40.74% for Pb, and 42.0% for Ag. A minimum mining width of 4.0 m was applied. Average Bulk density of 2.8 t/m3.
(5) Aripuanã Mine
The Qualified Person for the Mineral Reserves estimate is Jason J. Cox, P.Eng., a SLR Consulting (Canada) Ltd. employee. Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. Mineral Reserves are estimated at a NSR break-even cut-off value of US$48.11/t processed. Some incremental material with values between US$38.05/t and US$48.11/t was included. Mineral Reserves are estimated using average long-term metal prices of Zn: US$2,826.35/t (US$1.28/lb), Pb: US$2,043.95/t (US$0.90/lb); Cu: US$7,398.47/t (US$3.36/lb); Au: US$1,474.88/oz; and Ag: US$19.93/oz. Metallurgical recoveries are accounted for in the NSR calculations based on metallurgical test work and are variable as a function of head grade. Recoveries at the LOM average head grades for stratabound material are 89.42% for Zn, 81.06% for Pb, 60.00% for Cu, 75.10% for Ag, and 67.8% for Au. Recoveries at the LOM average head grades for stringer material are 88.68% for Cu, 50.00% for Ag, and 63.00% for Au. A minimum mining width of 4.0 m was applied. Bulk density varies depending on mineralization domain.
| Mineral Resources – NI 43-101 (Mines) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grade | Contained Metal | ||||||||||||
|
Interest (1)
|
Ownership (%) |
Class
|
Tonnage | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |||
|
Cerro Lindo Mine (2) |
83.48% |
Measured | 5.38 | 1.84 | 0.62 | 22.2 | 0.23 | – | 99.0 | 33.4 | 3,840 | 12.4 | – |
| Indicated | 3.22 | 1.15 | 0.49 | 25.6 | 0.24 | – | 37.0 | 15.8 | 2,650 | 7.7 | – | ||
| Subtotal | 8.60 | 1.58 | 0.57 | 23.5 | 0.23 | – | 136.0 | 49.2 | 6,490 | 20.1 | – | ||
| Inferred | 8.49 | 1.65 | 0.24 | 37.1 | 0.45 | – | 140.1 | 20.4 | 10,127 | 38.2 | – | ||
|
El Porvenir Mine (3) |
83.48% |
Measured | 0.35 | 3.31 | 0.21 | 70.5 | 1.10 | – | 11.6 | 0.7 | 793 | 3.9 | – |
| Indicated | 3.04 | 3.04 | 0.20 | 57.1 | 0.92 | – | 92.4 | 6.1 | 5,581 | 28.0 | – | ||
| Subtotal | 3.39 | 3.07 | 0.20 | 58.5 | 0.94 | – | 104.0 | 6.8 | 6,374 | 31.9 | – | ||
| Inferred | 10.68 | 3.83 | 0.19 | 72.9 | 1.05 | – | 409.0 | 20.3 | 25,032 | 112.1 | – | ||
|
Vazante Mine (4) |
100% |
Measured | 0.63 | 8.32 | – | 14.8 | 0.24 | – | 52.4 | – | 300 | 1.5 | – |
| Indicated | 3.90 | 5.97 | – | 6.8 | 0.19 | – | 233.0 | – | 858 | 7.6 | – | ||
| Subtotal | 4.53 | 6.30 | – | 8.0 | 0.20 | – | 285.4 | – | 1,158 | 9.1 | – | ||
| Inferred | 15.15 | 9.53 | – | 12.7 | 0.19 | – | 1,443.1 | – | 6,184 | 29.2 | – | ||
|
Aripuanã Mine (5) |
100% |
Measured | 0.40 | 1.87 | 0.41 | 23.4 | 0.70 | 0.40 | 7.5 | 1.6 | 301 | 2.8 | 5.1 |
| Indicated | 2.55 | 2.26 | 0.19 | 21.2 | 0.82 | 0.31 | 57.6 | 4.8 | 1,738 | 20.9 | 25.4 | ||
| Subtotal | 2.95 | 2.21 | 0.22 | 21.5 | 0.80 | 0.32 | 65.1 | 6.4 | 2,039 | 23.7 | 30.5 | ||
| Inferred | 38.55 | 2.41 | 0.30 | 29.5 | 1.02 | 0.46 | 929.1 | 115.7 | 36,563 | 393.2 | 570.1 | ||
|
Atacocha Mine |
75.96% |
Measured | 2.76 | 4.18 | – | 78.9 | 1.52 | – | 115.3 | – | 7,004 | 42.0 | – |
| Indicated | 4.31 | 4.15 | – | 76.0 | 1.43 | – | 178.9 | – | 10,535 | 61.6 | – | ||
| Subtotal | 7.07 | 4.16 | – | 77.2 | 1.47 | – | 294.2 | – | 17,539 | 103.6 | – | ||
| Inferred | 8.11 | 4.45 | – | 82.0 | 1.26 | – | 360.9 | – | 21,389 | 102.2 | – | ||
|
Atacocha Mine |
75.96% |
Measured | 3.19 | 1.04 | – | 36.8 | 1.02 | 0.25 | 33.2 | – | 3,774 | 32.5 | 25.6 |
| Indicated | 6.87 | 1.09 | – | 30.0 | 0.94 | 0.19 | 74.9 | – | 6.626 | 64.6 | 42.0 | ||
| Subtotal | 10.06 | 1.07 | – | 32.2 | 0.97 | 0.21 | 108.1 | – | 10,400 | 97.1 | 67.6 | ||
| Inferred | 3.84 | 1.13 | – | 31.7 | 1.01 | 0.20 | 43.4 | – | 3,914 | 38.8 | 24.7 | ||
|
Morro Agudo Mine (8) |
100% |
Measured | – | – | – | – | – | – | – | – | – | – | – |
| Indicated | 12.80 | 3.52 | – | – | 0.58 | – | 450.6 | – | – | 74.5 | – | ||
| Subtotal | 12.80 | 3.52 | – | – | 0.58 | – | 450.6 | – | – | 74.5 | – | ||
| Inferred | 4.07 | 3.90 | – | – | 0.57 | – | 158.7 | – | – | 23.1 | – | ||
|
Total Mines |
Measured | 12.71 | 2.51 | 0.28 | 39.2 | 0.75 | 0.08 | 319.0 | 35.7 | 16,019 | 95.1 | 30.7 | |
| Indicated | 36.66 | 3.08 | 0.07 | 23.7 | 0.73 | 0.06 | 1,128.9 | 26.7 | 27,984 | 267.0 | 67.4 | ||
| Total | 49.37 | 2.93 | 0.13 | 27.7 | 0.73 | 0.06 | 1,447.9 | 62.4 | 44,003 | 362.1 | 98.1 | ||
| Inferred | 88.82 | 3.92 | 0.18 | 36.1 | 0.83 | 0.21 | 3,482.7 | 156.4 | 103,201 | 736.6 | 594.8 | ||
| Mineral Resources – NI 43-101 (Zinc Projects) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grade | Contained Metal | ||||||||||||
|
Interest (1)
|
Ownership (%) |
Class
|
Tonnage | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |||
|
Hilarión & El Padrino (9) |
83.48% |
Measured | 14.54 | 3.39 | – | 30.9 | 0.69 | – | 492.9 | – | 14,445 | 100.3 | – |
| Indicated | 34.03 | 3.62 | – | 27.0 | 0.54 | – | 1,231.9 | – | 29,540 | 183.8 | – | ||
| Subtotal | 48.57 | 3.55 | – | 28.2 | 0.58 | – | 1,724.8 | – | 43,985 | 284.1 | – | ||
| Inferred | 42.17 | 4.06 | – | 25.0 | 0.41 | – | 1,712.1 | – | 33,895 | 172.9 | – | ||
|
Florida Canyon Zinc (10) |
50.93% |
Measured | 0.81 | 11.32 | – | 15.4 | 1.40 | – | 91.7 | – | 401 | 11.3 | – |
| Indicated | 1.63 | 10.28 | – | 14.9 | 1.31 | – | 167.6 | – | 781 | 21.4 | – | ||
| Subtotal | 2.44 | 10.63 | – | 15.1 | 1.34 | – | 259.3 | – | 1,182 | 32.7 | – | ||
| Inferred | 14.86 | 9.63 | – | 11.3 | 1.26 | – | 1,431.0 | – | 5,399 | 187.2 | – | ||
|
Total Zinc Projects |
Measured | 15.35 | 3.81 | – | 30.1 | 0.73 | – | 584.6 | – | 14,846 | 111.6 | – | |
| Indicated | 35.66 | 3.91 | – | 26.4 | 0.58 | – | 1,399.5 | – | 30,321 | 205.2 | – | ||
| Total | 51.01 | 3.89 | – | 27.5 | 0.62 | – | 1,984.1 | – | 45,167 | 316.8 | – | ||
| Inferred | 57.03 | 5.51 | – | 21.4 | 0.63 | – | 3,143.1 | – | 39,294 | 361.1 | – | ||
|
Total (Mines and Projects) |
Measured | 28.06 | 3.22 | 0.13 | 34.2 | 0.74 | 0.03 | 903.6 | 35.7 | 30,865 | 206.7 | 30.7 | |
| Indicated | 72.32 | 3.50 | 0.04 | 25.1 | 0.65 | 0.03 | 2,258.4 | 26.7 | 58,305 | 472.2 | 67.4 | ||
| Total | 100.38 | 3.42 | 0.06 | 27.6 | 0.68 | 0.03 | 3,432.0 | 62.4 | 89,170 | 678.9 | 98.3 | ||
| Inferred | 145.85 | 4.54 | 0.11 | 30.4 | 0.75 | 0.13 | 6,625.8 | 156.4 | 142,495 | 1,096.7 | 594.8 | ||
| Mineral Resources – NI 43-101 (Copper Projects) | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grade | Contained Metal | ||||||||||||||
|
Interest (1)
|
Ownership (%) |
Class
|
Tonnage | Zinc | Copper | Silver | Lead | Gold | Moly | Zinc | Copper | Silver | Lead | Gold | Moly |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (%) | (kt) | (kt) | (koz) | (kt) | (koz) | (kt) | |||
|
Magistral Project (11) |
83.48% |
Measured | 98.69 | – | 0.52 | 2.8 | – | – | 0.050 | – | 513.2 | 8,884 | – | – | 49.3 |
| Indicated | 90.68 | – | 0.43 | 2.8 | – | – | 0.040 | – | 389.9 | 8,163 | – | – | 36.3 | ||
| Total | 189.37 | – | 0.48 | 2.8 | – | – | 0.045 | – | 903.1 | 17,047 | – | – | 85.6 | ||
| Inferred | 11.06 | – | 0.38 | 3.1 | – | – | 0.050 | – | 42.0 | 1,103 | – | – | 5.5 | ||
Notes: The estimation of Mineral Reserves involves assumptions as to future commodity prices and as to technical mining matters. Numbers and totals may not sum due to rounding. The Qualified Person responsible for the Mineral Reserves estimates are not aware of any mining, metallurgical, infrastructure, permitting, or other relevant factors that could materially affect the Mineral Reserve estimate.
(1) The estimation of Mineral Resources involves assumptions as to future commodity prices and as to technical mining matters. Numbers and totals may not sum due to rounding. Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability.
(2) Cerro Lindo Mine
Mineral Resources are effective date as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (Geo), a Nexa Resources employee.
Mineral Resources are reported on an 100% ownership basis. Nexa owns 83.48%.
Mineral Resources are estimated at an NSR cut-off value of US$ 42.65/t.
Mineral Resources are estimated using average long term metal prices of Zn: US$3,250.31/t (US$1.47/lb), Pb: US$2,350.54/t (US$1.07/lb); Cu: US$8,508.24/t (US$3.86/lb); and Ag: US$22.92/oz.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at average head grades are 88.72% for Zn, 66.75% for Pb, 85.92% for Cu, and 68.8% for Ag.
Mineral Resources are reported within underground mining shapes.
Dilution and extraction factors are applied based on stope type and location.
A minimum mining width of 4.0m was used.
Bulk density varies depending on mineralization domain.
(3) El Porvenir Mine
Mineral Resources are effective date as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM, a Nexa Resources employee.
Mineral Resources are reported on an 100% ownership basis. Nexa owns 83.48%.
Mineral Resources are estimated at NSR cut-off grade values ranging from US$57.99/t to US$60.71/t for SLS areas and US$ 59.65/t to US$62.37 for C&F areas depending on the zone.
Mineral Resources are estimated using average long term metal prices of Zn: US$3,250.31/t (US$1.47/lb), Pb: US$2,350.54/t (US$1.07/lb); Cu: US$8,508.24/t (US$3.86/lb); and Ag: US$22.92/oz.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the average head grades are 88.85% for Zn, 79.73% for Pb, 11.81% for Cu, and 63.0% for Ag.
Mineral Resources are reported within underground mining shapes.
A minimum mining width of 4.0m and 3.0m was used for C&F and SLS resource stopes shapes respectively.
Bulk density varies depending on mineralization domain.
(4) Vazante Mine
Mineral Resources are effective date as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM , a Nexa Resources employee.
Mineral Resources are reported on a 100% Nexa ownership basis. Nexa owns 100%.
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$23.13/t for soil and US$28.38/t for fresh rock and transition material. For Aroeira Tailings the resources are estimated at a NSR cut-off value of US$29.40/t and for Hypogene Mineralization (Willeminte) a cut-off value of US$60.61/t for all resources shapes.
Forecast long term metal prices used for the NSR calculation are: Zn: US$3,250.31/t (US$1.47/lb), Pb: US$2,350.54/t (US$1.07/lb); and Ag: US$22.92/oz. An average long-term R$/US$ exchange rate of 4.96 was used.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the average hypogene head grades are 87.20% for Zn, 40.74% for Pb, and 42.0% for Ag, supergene (calamine) is 55.00% for Zn, and tailings are 68.11% for Zn, 38.46% for Pb, and 42.00% for Ag.
Mineral Resources are reported within underground mining shapes with minimum mining width of 3.0m for the willemite mineralization, open pit shell for Calamine and above original topography for tailings.
Bulk density varies depending on mineralization domain
Density was assigned based on rock type.
(5) Aripuanã Mine
Mineral Resources are effective as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is Renan Lopes, M.Sc. MAusIMM CP (Geo), a SLR Consulting employee.
The Mineral Resources estimate is reported on a 100% ownership basis. Mineral Resources are reported using a cut-of value of US$48.11/t. Forecast long term metal prices used for the NSR calculation are: Zn: US$3,250.31/t (US$1.47/lb), Pb: US$2,350.54/t (US$1.07/lb); Cu: US$8,508.24/t (US$3.86/lb); Au: US$1,696.11/oz; and Ag: US$22.92/oz. Metallurgical recoveries are accounted for in the NSR calculations based on metallurgical test work and are variable as a function of head grade and ore type. Recoveries at the LOM average head grades for stratabound material are 89.42% for Zn, 81.06% for Pb, 60.0% for Cu, 75.10% for Ag, and 67.80% for Au. Recoveries at the LOM average head grades for stringer material are 88.68% for Cu, 50.0% for Ag, and 63.0% for Au. Bulk density varies depending on mineralization domain.
(6) Atacocha Mine (Underground)
Mineral Resources have effective date as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM, a Nexa Resources employee.
Mineral Resources are reported on an 100% ownership basis. Nexa owns 75.96%.
Mineral Resources are estimated at a NSR cut-off value of US$62.81/t for resources shapes.
The NSR cut-offs are calculated based on the LOM costs using average long-term metal prices of Zn: US$ 3,250.3/t (US$ 1.47/lb), Pb: US$ 2,350.5/t (US$ 1.07/lb), Ag: US$ 22.92/oz.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the LOM average head grades are 85.35% for Zn, 84.65% for Pb, and 76.19% for Ag.
Mineral Resources are reported within underground mining shapes.
A minimum mining width of 4.0 m was used.
Bulk density varies depending on mineralization domain.
(7) Atacocha Mine (Open Pit)
Mineral Resources have effective date as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (Geo), a Nexa Resources employee.
The Mineral Resources is reported on an 100% ownership basis. Nexa owns 75.96%.
Mineral Resources are estimated at a NSR cut-off value of US$23.81/t. Some marginal material with cut-off value of US$21.69/t was included.
The NSR cut-offs are calculated based on an average long-term metal price of Zn: US$ 3,250.3/t (US$1.47/lb), Pb US$ 2,350.5/t (US$1.07/lb), Au US$ 1,696.11/oz and Ag US$ 22.92/oz.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the LOM average head grades are 70.44% for Zn, 83.64% for Pb, 75.76% for Ag, and 65.46% for Au.
Mineral Resources are reported within optimized pit shell.
Mineral Resources are stated considering dilution into the regularized block.
Bulk density varies depending on mineralization domain.
(8) Morro Agudo Mine
Mineral Resources are effective date as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., MAusIMM (Geo), a Nexa Resources employee.
The Mineral Resources estimate is reported on a 100% ownership basis. Nexa owns 100%.
Mineral Resources are reported using a NSR cut-of value of based on the LOM costs for Morro Agudo: US$ 52.43/t and Bonsucesso: US$ 55.85/t.
The NSR cut-offs are calculated based on an average long-term metal price of Zn: US$ 3,250.3/t (US$ 1.47/lb) and Pb: US$ 2,350.5/t (US$ 1.07/lb); and metallurgical recoveries are based on historical processing data: for Morro Agudo are 92.50% for Zn and 61.10% for Pb, and for Bonsucesso are 92.00% for Zn and 72.00% for Pb.
Mineral Resources are reported within underground mining shapes.
A minimum thickness of 3.0 m was applied for Bonsucesso and 4.5 m for Morro Agudo.
Bulk density varies depending on mineralization domain.
(9) Hilarión
Mineral Resources have effective date as of December 31, 2022.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (Geo), a Nexa Resources employee.
Mineral Resources are reported on a 100% ownership basis. Nexa owns 83.48%.
Mineral resources are estimated at a NSR cut-off value of US$45.00/t for SLS resource shapes for the Hilarión deposit, and US$50.00/t for Room & Pillar (R&P) resource shapes for the El Padrino deposit.
Mineral Resources are estimated at average long-term metal prices of Zn: US$ 3,245.91/t (US$1.47/lb); Pb: US$2,332.46/t (US$1.06/lb) and Ag: US$ 22.66/oz.
Mineral Resources are reported within underground mining shapes.
A minimum mining width of 3.0 m was used for Hilarión and El Padrino.
Bulk density varies depending on mineralization domain
(10) Florida Canyon Zinc
Mineral Resources have an effective date as of October 30, 2020.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (Geo), a Nexa Resources employee.
Mineral Resources are reported on a 100% ownership basis. Nexa owns 50.93%.
Mineral Resources are reported using a cut-off values of US$41.40/t NSR for SLS, US$42.93/t for C&F and US$40.61/t for Room & Pillar mine areas.
Forecast long term metal prices used for the NSR calculation are Zn: US$ 2,816.35t (US$ 1.28/lb); Pb: US$ 2,196.50/t (US$ 1.00/lb) and Ag: US$ 19.38/oz.
Average metallurgical recoveries for the resource are Zinc (80%), Lead (74%) and Silver (52%).
Mineral Resources are reported within underground mining shapes.
Minimum thickness is 3.0 m for SLS and C&F, and 4.0 m for Room & Pillar.
Bulk density varies depending on mineralization domain.
(11) Magistral
Mineral Resources have effective date as of April 15th, 2021
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (Geo), a Nexa Resources employee.
Mineral Resources are reported on a 100% ownership basis. Nexa owns 83.48%.
Mineral Resources are estimated at NSR cut-off values of US$5.99/t for porphyry, US$5.51/t for mixed, and US$5.48/t for skarn rock types.
Metallurgical recoveries are accounted for in the NSR calculations based on metallurgical data and vary from 79.3% in skarn to 92.5% in San Ernesto porphyry for Cu, 51.3% in skarn and 79.2% in San Ernesto porphyry for Mo, and 70% for Ag.
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