NI 43-101 Mineral Resources

Notes:

1. The Mineral Resource estimate was prepared by Dr. Adrian Martínez Vargas, P.Geo., Senior Resource Geologist, and employee of CSA Global Consultants Canada Limited, an ERM Group company, and an independent Qualified Person for the purposes of NI 43-101.
2. Numbers have been rounded to reflect the precision of a Mineral Resource estimate, therefore numbers may not total.
3. The reporting cut-off is calculated as the marginal NSR that equals total estimated mining (1 US$/t for stockpiles), processing (8 US$/t), and administration costs (2 US$/t), assumed metallurgical extraction by multiple stage flotation, and metal prices of Zn 2,650 US$/t, Pb 2,125 US$/t, and Ag 16 US$/oz. Metallurgical processing recoveries were modelled using test work and production data provided to CDPR by Volcan from its current operations at Cerro de Pasco which are processing similar material to that within the Excelsior Stockpile.
4. A bulk density of 1.98 t/m³ is used.
5. Block model grade interpolation was undertaken using ordinary kriging.
6. The average grade estimates reflect resources in-situ and do not include modifying factors such as external dilution, mining losses and process recovery losses. However, resources were reported based on a regularized model that included dilution with low-grade material.
7. The Mineral Resource estimate for the surface stockpile is constrained by the vertical lateral limits of the El Metalurgista concession boundaries and the physical limits of the stockpile surfaces within the concession.
8. Mineral Resources are estimated and classified in accordance with CIM Definition Standards for Mineral Resources and Mineral Reserves, adopted by the CIM Council on May 10, 2014 using the Estimation of Mineral Resource and Mineral Reserves Best Practice Guidelines, adopted by the CIM Council on November 29, 2019.
9. Mineral Resources are not Reserves and, as such, do not have demonstrated economic viability.
10. One troy ounce (oz) equals 31.10348 g