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 17, 2022, the publication of updated information relating to mineral reserves and resources as of December 31, 2021. 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 | 24.30 | 1.61 | 0.65 | 21.8 | 0.21 | – | 392.2 | 158.3 | 17,030 | 50.6 | – |
| Probable | 19.74 | 1.21 | 0.59 | 22.9 | 0.20 | – | 238.0 | 116.2 | 14,519 | 39.1 | – | ||
| Subtotal | 44.04 | 1.43 | 0.62 | 22.3 | 0.20 | – | 630.3 | 274.4 | 31,549 | 89.7 | – | ||
|
El Porvenir Mine (3) |
83.48% |
Proven | 3.32 | 3.70 | 0.24 | 68.6 | 1.08 | – | 122.8 | 8.1 | 7.329 | 35.7 | – |
| Probable | 12.00 | 3.54 | 0.19 | 69.8 | 1.03 | – | 424.8 | 23.3 | 26,912 | 124.1 | – | ||
| Subtotal | 15.32 | 3.57 | 0.20 | 69.5 | 1.04 | – | 547.5 | 31.3 | 34,242 | 159.8 | – | ||
|
Vazante Mine (4) |
100% |
Proven | 7.39 | 8.90 | – | 17.2 | 0.25 | – | 657.6 | – | 4,097 | 18.8 | – |
| Probable | 8.52 | 8.66 | – | 10.6 | 0.19 | – | 737.6 | – | 2,896 | 16.4 | – | ||
| Subtotal | 15.91 | 8.77 | – | 13.7 | 0.22 | – | 1,395.2 | – | 6,992 | 35.3 | – | ||
|
Aripuanã Project (5) |
100% |
Proven | 8.97 | 3.80 | 0.28 | 35.7 | 1.43 | 0.26 | 340.7 | 25.4 | 10,279 | 128.1 | 75.2 |
| Probable | 12.82 | 3.47 | 0.19 | 32.1 | 1.31 | 0.32 | 445.0 | 24.6 | 13,216 | 167.4 | 132.8 | ||
| 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 | 43.98 | 3.44 | 0.44 | 27.4 | 0.53 | 0.05 | 1,513.3 | 191.7 | 38,736 | 233.3 | 75.2 | |
| Probable | 53.08 | 3.48 | 0.31 | 33.7 | 0.65 | 0.08 | 1,845.4 | 164.0 | 57,543 | 347.0 | 132.8 | ||
| Total | 97.06 | 3.46 | 0.37 | 30.9 | 0.60 | 0.07 | 3,358.6 | 355.7 | 96,279 | 580.2 | 208.0 | ||
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 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 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
Qualified Person for the Mineral Reserves estimate is Jason J. Cox, P.Eng., a SLR Consulting Ltd. employee.
Mineral Reserves are estimated at an NSR break-even cut-off value of US$38.73/t processed. Some incremental material with values between US$29.13/t and US$38.84/t was included.
Mineral Reserves are estimated using average long-term metal prices of Zn: US2,722.20/t (US$1.23/lb), Pb: US$1,997.21/t (US$0.91/lb); Cu: US$7,288.26/t (US$3.31/lb); Au: US$1,454.12/oz; and Ag: US$19.68/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 88.1% for Zn, 68.9% for Pb, 86.6% for Cu, and 68.8% for Ag.
Dilution and extraction factors are applied based on stope type and location.
A minimum mining width of 5.0m was used.
Bulk density varies depending on mineralization domain.
(3) El Porvenir Mine
Qualified Person for the Mineral Reserves estimate isJason J. Cox, P.Eng., a SLR Consulting Ltd. employee.
Mineral Reserves are estimated at NSR cut-off values ranging from US$57.63/t to US$62.19/t depending on the zone and mining method.
Mineral Reserves are estimated using average long-term prices of Zn: US$2,722.20/t (US$ 1.23/lb); Pb: US$1,997.21/t (US$0.91/lb); Cu: US$7,288.26/t (US$3.31/lb); and Ag: US$19.68/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 89.59% for Zn,77.74% for Pb, 14.29% for Cu, and 63% for Ag.
A minimum mining width of 5.0m was used.
Density is 3.12 t/m3.
(4) Vazante Mine
Qualified Person for the Mineral Reserves estimate is Jason J. Cox, P.Eng., a SLR Consulting Ltd. employee.
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$19.68/oz Ag.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the LOM average head grades are 84.7% for Zn, 22.1% for Pb, and 42.0% for Ag. An average long-term Brazilian Real (R$)/US$ exchange rate of 4.98 was used.
A minimum mining width of 4.0 m was used.
Bulk density is 3.1 t/m³.
(5) Aripuanã Project
The Qualified Person for the Mineral Reserves estimate is Jason J. Cox, P.Eng., a SLR Consulting Ltd. employee.
Mineral Reserves are estimated at an NSR break-even cut-off value of US$47.91/t processed. Some incremental material with values between US$39.79/t and US$47.91/t was included.
Mineral Reserves are estimated using an average long-term zinc price of Zn: US2,722.20/t (US$1.23/lb), Pb: US$1997.21/t (US$0.91/lb); Cu: US$7,288.26/t (US$3.31/lb); Au: US$1,454.12/oz; and Ag: US$19.68/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 89.4% for Zn, 83.3% for Pb, 59.3% for Cu, 76.0% for Ag, and 70.0% for Au. Recoveries at the LOM average head grades for stringer material are 87.8% for Cu, 50.0% for Ag, and 63.0% for Au.
A minimum mining width of 4.0m was used.
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 | 3.88 | 1.93 | 0.61 | 21.6 | 0.23 | – | 74.9 | 23.7 | 2,694 | 8.9 | – |
| Indicated | 3.56 | 1.04 | 0.48 | 28.1 | 0.26 | – | 37.0 | 17.1 | 3,216 | 9.3 | – | ||
| Subtotal | 7.44 | 1.50 | 0.55 | 24.7 | 0.24 | – | 111.9 | 40.8 | 5,910 | 18.2 | – | ||
| Inferred | 8.23 | 1.40 | 0.29 | 39.2 | 0.46 | – | 115.2 | 23.9 | 10,372 | 37.9 | – | ||
|
El Porvenir Mine (3) |
83.48% |
Measured | 0.65 | 2.66 | 0.20 | 60.7 | 0.85 | – | 17.3 | 1.3 | 1,269 | 5.5 | – |
| Indicated | 3.03 | 2.96 | 0.20 | 48.2 | 0.76 | – | 89.7 | 6.1 | 4,695 | 23.0 | – | ||
| Subtotal | 3.68 | 2.91 | 0.20 | 50.4 | 0.78 | – | 107.0 | 7.4 | 5,964 | 28.5 | – | ||
| Inferred | 10.42 | 3.85 | – | 69.2 | 0.95 | – | 401.2 | 21.9 | 23,183 | 99.0 | – | ||
|
Vazante Mine (4) |
100% |
Measured | 2.34 | 3.63 | – | 6.2 | 0.12 | – | 84.9 | – | 466 | 2.8 | – |
| Indicated | 2.94 | 5.53 | – | 5.6 | 0.07 | – | 162.7 | – | 311 | 2.1 | – | ||
| Subtotal | 5.28 | 4.69 | – | 4.6 | 0.09 | – | 247.6 | – | 777 | 4.9 | – | ||
| Inferred | 15.44 | 7.52 | – | 11.2 | 0.19 | – | 1,192.1 | – | 5,395 | 30.0 | – | ||
|
Atacocha Mine |
75.96% |
Measured | 3.79 | 4.87 | – | 101.1 | 1.98 | – | 184.6 | – | 12,319 | 75.0 | – |
| Indicated | 4.38 | 4.14 | – | 75.6 | 1.41 | – | 181.3 | – | 10,643 | 61.8 | – | ||
| Subtotal | 8.17 | 4.48 | – | 87.4 | 1.67 | – | 365.9 | – | 22,962 | 136.8 | – | ||
| Inferred | 8.15 | 4.43 | – | 81.8 | 1.25 | – | 361.0 | – | 21,434 | 101.9 | – | ||
|
Atacocha Mine |
75.96% |
Measured | 3.28 | 1.10 | – | 28.9 | 0.81 | 0.21 | 36.1 | – | 3,048 | 26.6 | 22.1 |
| Indicated | 8.16 | 1.07 | – | 30.8 | 0.94 | 0.18 | 87.3 | – | 8,080 | 76.7 | 47.2 | ||
| Subtotal | 11.44 | 1.08 | – | 30.3 | 0.90 | 0.19 | 123.4 | – | 11,128 | 103.3 | 69.3 | ||
| Inferred | 2.00 | 0.93 | – | 32.0 | 0.92 | 0.26 | 18.6 | – | 2,058 | 18.4 | 16.7 | ||
|
Morro Agudo Mine (7) |
100% |
Measured | – | – | – | – | – | – | – | – | – | – | – |
| Indicated | 13.92 | 3.39 | – | – | 0.59 | – | 472.1 | – | – | 82.4 | – | ||
| Subtotal | 13.92 | 3.39 | – | – | 0.59 | – | 472.1 | – | – | 82.4 | – | ||
| Inferred | 4.40 | 3.26 | – | – | 0.47 | – | 143.6 | – | – | 20.8 | – | ||
|
Total Mines |
Measured | 13.94 | 2.85 | 0.18 | 44.2 | 0.85 | 0.05 | 397.8 | 25.0 | 19,796 | 118.8 | 22.1 | |
| Indicated | 35.99 | 2.86 | 0.06 | 23.3 | 0.71 | 0.04 | 1,030.1 | 23.2 | 26,945 | 255.3 | 47.2 | ||
| Total | 49.93 | 2.86 | 0.10 | 29.1 | 0.75 | 0.04 | 1,427.9 | 48.2 | 46,741 | 374.1 | 69.3 | ||
| Inferred | 48.64 | 4.59 | 0.09 | 39.9 | 0.63 | 0.01 | 2,231.7 | 45.8 | 62,442 | 308.0 | 16.7 | ||
| 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) | |||
|
Aripuanã Project (8) |
100% |
Measured | 0.44 | 1.79 | 0.34 | 17.5 | 0.59 | 0.35 | 7.9 | 1.5 | 248 | 2.6 | 5.0 |
| Indicated | 2.80 | 2.18 | 0.30 | 19.9 | 0.74 | 0.48 | 61.0 | 8.4 | 1,791 | 20.7 | 43.2 | ||
| Subtotal | 3.24 | 2.13 | 0.31 | 19.6 | 0.72 | 0.46 | 68.9 | 9.9 | 2,039 | 23.3 | 48.2 | ||
| Inferred | 38.48 | 3.51 | 0.33 | 35.5 | 1.29 | 0.55 | 1,350.6 | 127.0 | 43,919 | 496.4 | 680.4 | ||
| Shalipayco Project (9) | 62.61% | Measured | 3.78 | 4.18 | – | 28.9 | 0.46 | – | 158.0 | – | 3,512 | 17.4 | – |
| Indicated | 5.69 | 4.61 | – | 32.6 | 0.50 | – | 262.3 | – | 5,964 | 28.5 | – | ||
| Subtotal | 9.47 | 4.44 | – | 31.1 | 0.48 | – | 420.3 | – | 9,476 | 45.9 | – | ||
| Inferred | 32.38 | 4.13 | – | 31.1 | 0.47 | – | 1,337.3 | – | 32,376 | 152.2 | – | ||
|
Hilarión Project (10) |
83.48% |
Measured | 24.73 | 3.43 | – | 32.8 | 0.72 | – | 848.2 | – | 26,079 | 178.1 | – |
| Indicated | 34.23 | 3.61 | – | 25.7 | 0.58 | – | 1,235.7 | – | 28,283 | 198.5 | – | ||
| Subtotal | 58.96 | 3.53 | – | 28.7 | 0.64 | – | 2,083.9 | – | 54,362 | 376.6 | – | ||
| Inferred | 25.34 | 3.52 | – | 28.4 | 0.69 | – | 892.0 | – | 23,137 | 174.8 | – | ||
|
Florida Canyon Project (11) |
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 | – | ||
|
Caçapava do Sul Project (12) |
56.00% |
Measured | 4.90 | 1.52 | – | 10.0 | 2.11 | – | 74.5 | – | 1,575 | 103.4 | – |
| Indicated | 8.11 | 1.08 | 0.08 | 27.0 | 1.89 | – | 87.6 | 6.5 | 7,040 | 153.3 | – | ||
| Subtotal | 13.01 | 1.25 | 0.05 | 20.6 | 1.97 | – | 162.1 | 6.5 | 8,615 | 256.7 | – | ||
| Inferred | 13.25 | 0.86 | 0.12 | 21.0 | 1.94 | – | 114.0 | 15.9 | 8,946 | 257.1 | – | ||
|
Total Zinc Projects |
Measured | 34.66 | 3.41 | – | 28.6 | 0.90 | – | 1,180.3 | 1.5 | 31,815 | 312.8 | 5.0 | |
| Indicated | 52.46 | 3.46 | 0.03 | 26.0 | 0.81 | 0.03 | 1,814.2 | 14.9 | 43,859 | 422.4 | 43.2 | ||
| Subtotal | 87.12 | 3.44 | 0.02 | 27.0 | 0.84 | 0.02 | 2,994.5 | 16.4 | 75,674 | 735.2 | 48.2 | ||
| Inferred | 124.31 | 4.12 | 0.11 | 28.5 | 1.02 | 0.17 | 5,124.9 | 142.9 | 113,777 | 1,267.7 | 680.4 | ||
|
Total (Mines and Projects) |
Measured | 48.60 | 3.25 | 0.05 | 33.0 | 0.89 | 0.02 | 1,578.1 | 26.5 | 51,611 | 431.6 | 27.1 | |
| Indicated | 88.45 | 3.22 | 0.04 | 24.9 | 0.77 | 0.03 | 2,844.3 | 38.1 | 70,804 | 677.7 | 90.4 | ||
| Subtotal | 137.05 | 3.23 | 0.05 | 27.8 | 0.81 | 0.03 | 4,422.4 | 64.6 | 122,415 | 1,109.3 | 117.5 | ||
| Inferred | 172.95 | 4.25 | 0.11 | 31.7 | 0.91 | 0.13 | 7,356.6 | 188.7 | 176,219 | 1,575.7 | 697.1 | ||
| 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 (13) |
83.48% |
Measured | 98.69 | – | 0.52 | 2.8 | – | – | 0.05 | – | 513.2 | 8,884 | – | – | 49.3 |
| Indicated | 90.68 | – | 0.43 | 2.8 | – | – | 0.04 | – | 389.9 | 8,163 | – | – | 36.3 | ||
| Subtotal | 189.37 | – | 0.48 | 2.8 | – | – | 0.05 | – | 903.1 | 17,047 | – | – | 85.6 | ||
| Inferred | 11.06 | – | 0.38 | 3.1 | – | – | 0.05 | – | 42.0 | 1,103 | – | – | 5.5 | ||
|
Pukaqaqa Project (14) |
83.48% |
Measured | 107.30 | – | 0.43 | – | – | – | – | – | 461.4 | – | – | – | – |
| Indicated | 201.70 | – | 0.39 | – | – | – | – | – | 786.6 | – | – | – | – | ||
| Subtotal | 309.00 | – | 0.40 | – | – | – | – | – | 1,248.0 | – | – | – | – | ||
| Inferred | 40.10 | – | 0.34 | – | – | – | – | – | 136.3 | – | – | – | – | ||
|
Total Copper Projects |
Measured | 205.99 | – | 0.47 | 1.3 | – | – | 0.02 | – | 974.6 | 8,884 | – | – | 49.3 | |
| Indicated | 292.38 | – | 0.40 | 0.9 | – | – | 0.01 | – | 1,176.6 | 8,163 | – | – | 36.3 | ||
| Total | 498.37 | – | 0.43 | 1.1 | – | – | 0.02 | – | 2,151.1 | 17,047 | – | – | 85.6 | ||
| Inferred | 51.16 | – | 0.35 | 0.7 | – | – | 0.01 | – | 178.4 | 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 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 Resources 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 Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are estimated at an NSR cut-off value of US$ 38.84/t.
Mineral Resources are estimated using average long-term metal prices of Zn: US$3,130.52/t (US$1.42/lb), Pb: US$2,296.79/t (US$1.04/lb); Cu: US$8,381.5/t (US$3.80/lb); and Ag: US$22.63/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 88.1% for Zn, 68.9% for Pb, are 86.6% for Cu, and 68.8% for Ag.
Dilution and extraction factors are applied based on stope type and location.
A minimum mining width of 4.0 m was used.
Bulk density varies depending on mineralization domain.
(3) El Porvenir Mine
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are estimated at NSR cut-off values ranging from of US$57.45/t to US$60.39/t for SLS areas and US$ 59.24/t to US$62.18 for C&F areas depending on the zone.
Mineral Resources are estimated using average long-term metal prices of Zn: US$3,130.52/t (US$1.42/lb), Pb: US$2,296.79/t (US$1.04/lb); Cu: US$8,381.50/t (US$3.80/lb) and Ag: US$22.63/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 89.59% for Zn, 77.74% for Pb, 14.29% for Cu, and 63% for Ag.
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
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are reported on a 100% Nexa attributable ownership basis.
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$22.63/oz.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the LOM average hypogene head grades are 84.7% for Zn, 22.1% for Pb, and 42.0% for Ag.
An average long-term R$/US$ exchange rate of 4.98 was used.
Mineral Resources are reported within underground mining shapes with minimum mining width of 3.0m for the willemite mineralization.
Density was assigned based on rock type.
(5) Atacocha Mine (Underground)
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are estimated at a NSR cut-off value of US$ 63.68/t for C&F resources shapes.
Mineral Resources are estimated using average long-term metal prices of Zn: US$3,130.52/t (US$1.42/lb), Pb: US$2,296.79/t (US$1.04/lb); Cu: US$8,381.50/t (US$3.80/lb) and Ag: US$22.63/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 85.44% for Zn, 84.92% for Pb, and 76% for Ag
A minimum mining width of 4.0m was used.
Bulk density was assigned based on rock type.
(6) Atacocha Mine (Open Pit)
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are estimated at a NSR cut-off value of US$18.17/t. Some marginal material with cut-off value of US$15.66/t was included.
Mineral Resources are estimated using average long-term metal prices of Zn: US$3,130.52/t (US$1.42/lb), Pb: US$2,296.79/t (US$1.04/lb); Cu: US$8,381.50/t (US$3.80/lb); Au: US$1,672.24/oz; and Ag: US$22.63/oz.
Metallurgical recoveries are accounted for in the NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at the LOM average head grades are 76.05% for Zn, 80.0% for Pb, 76% for Ag, and 53% for Au.
Bulk density was assigned based on rock type.
Mineral Resources are reported within optimized pitshell.
Mineral Resources are stated as in situ with no consideration for planned or unplanned mining dilution.
(7) Morro Agudo Mine
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are reported within underground mining shapes.
The NSR cut-offs are calculated based on the LOM costs for each mine – Morro Agudo: US$ 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.
Recoveries at the LOM average head grades are 89.84% for Zn and 75.52% for Pb.
A minimum thickness of 3.0m was applied for Bonsucesso and 4.5m for Morro Agudo underground.
Density was assigned based on rock type.
(8) Aripuanã Project
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are reported using a cut-of value of US$47.91/t.
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); Cu: US$8,381.50/t (US$3.80/lb); Au: US$1,672.24/oz; and Ag: US$22.63/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 mineralization type. Recoveries at the LOM average head grades for stratabound material are 89.4% for Zn, 83.3% for Pb, 59.3% for Cu, 76.0% for Ag, and 70.0% for Au.
Recoveries at the LOM average head grades for stringer material are 87.8% for Cu, 50.0% for Ag, and 63.0% for Au.Bulk density varies depending on mineralization domain.
(9) Shalipayco Project
Mineral Resources have an effective date as December 31, 2018.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are reported above a NSR cut-off value of US$45/t and metallurgical recoveries are based on metallurgical test work: 88.0% for Zn and 77.5% for Pb.
Forecast long-term metal prices used for the NSR calculation are: Zn: US$3,034.28/t; Pb: US$2,529.54/t; and Ag: US$21.58/oz.
A minimum mining width of 2.0m was applied.
Density was assigned based on rock type.
Mineral Resources are stated as in situ with no consideration for planned or unplanned mining dilution.
(10) Hilarion Project
Mineral Resources have an effective date as of December 31, 2019.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are estimated at a NSR cut-off value of US$35.00/t for SLS resource shapes for Hilarión deposit, and an NSR cut-off value of US$45.00/t for SLS resource shapes and US$50.00/t for Room and Pillar (R&P) resource shapes for El Padrino deposit.
Mineral Resources are estimated at average long-term metal prices of Zn: US$2,956.65/t (US$1.34/lb); Pb: US$2,303.14/t (US$1.04/lb); Cu: US$7,523.30/t.
(US$3.41/lb); and Ag: US$19.61/oz.
A minimum mining width of 3.0m was used for Hilarión and El Padrino.
Bulk density varies depending on mineralization domain.
(11) Florida Canyon Projec
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 (CP) Geo, a Nexa Resources employee.
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$2,816t (US$1.27/lb); Pb: US$ 2,196.5/t (US$1.00/lb) and Ag: US$19.40/oz.
Minimum thickness are 3.0m for SLS and C&F, and 4.0 m for R&P.
Mineral Resources are constrained by preliminary pit shells.
Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability.
(12) Caçapava do Sul Project
Mineral Resources have an effective date as of March 17, 2017.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are reported within an optimized pit shell.
Density was assigned based on rock type.
Mineral Resources are reported above a NSR cut-off value of US$13.25/t.
Forecast long-term metal prices used for the NSR calculation are: Zn US$2,778/t; Pb US$2,227/t; Cu US$6,790/t; and Ag US$21.78/oz.
Mineral Resources are stated as in situ with no consideration for planned or unplanned mining dilution.
(13) Magistral Project
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are constrained within a Whittle optimized pit shell.
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;
Mineral Resources are estimated using an average long-term metal prices of US$7,193.45/t Cu, US$21.34/oz Ag, and US$9.90/lb of Mo.
A minimum mining width of 10m was used.
Bulk densities for range between 2.59 t/m3 and 3.30 t/m3 depending on the rock type.
(14) Pukaqaqa Project
Mineral Resources have an effective date as of July 31, 2017.
The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM (CP) Geo, a Nexa Resources employee.
Mineral Resources are constrained within an optimized pit shell.
Mineral Resources are estimated using a copper price of US$5,710/t (US$2.59/lb) and an exchange rate of US$0.80 to C$1.00.
Mineral Resources are reported above a 0.2% Cu cut-off grade.
Mineral Resources are stated as in situ with no consideration for planned or unplanned mining dilution.
Density was assigned based on rock type.
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