Reserves and Resources

Note: totals may not add up correctly due to rounding.

¹ Mineral resources are exclusive of mineral reserves and do not have demonstrated economic viability.
² Mineral reserves and resources calculated using metal prices of $1.17 per pound zinc (includes premium), $1,375 per ounce gold, $3.10 per pound copper, $17.00 per ounce of silver.
³ Mineral reserves are estimated at an NSR cut-off of $101 per tonne for waste filled mining areas and a minimum of $113 per tonne for paste filled mining areas.
⁴ Mineral resources are estimated at a minimum NSR cut-off of $101 per tonne.

Note: totals may not add up correctly due to rounding.

¹ WIM mineral reserves are estimated at a minimum net smelter return (“NSR”) cut-off of C$150 per tonne, assuming processing recoveries of 98% for copper, 88% for gold and 70% for silver, and using long-term prices of $3.10 per pound copper, $1,375 per ounce gold and $17.00 per ounce silver. 3 Zone mineral reserves are estimated at a minimum NSR cut-off of C$150 per tonne, assuming processing recoveries of 85% for gold, and using a long-term price of $1,375 per ounce gold.
² Mineral resources are exclusive of mineral reserves and do not have demonstrated economic viability. New Britannia mineral resource estimates have been reported at a minimum true width of 1.5 metres and with a cut-off grade varying from 2 grams per tonne (at the lower part of New Britannia) to 3.5 grams per tonne (at the upper part of New Britannia).

Note: totals may not add up correctly due to rounding.

¹ Mineral resources are exclusive of mineral reserves and do not have demonstrated economic viability. 1901 mineral resources are estimated at a minimum NSR cut-off of $170 per tonne, assuming processing recoveries of 73% for copper, 94% for zinc, 48% for gold and 47% for silver, and using long-term prices of $3.10 per pound copper, $1,260 per ounce gold, $1.10 per pound zinc and $18.00 per ounce silver. Watts mineral resources are estimated at a minimum NSR cut-off of $150 per tonne, assuming processing recoveries of 87% for copper, 80% for zinc, 65% for gold and 64% for silver, and using long-term prices of $3.10 per pound copper, $1,375 per ounce gold, $1.10 per pound zinc and $17.00 per ounce silver. Pen II mineral resources are estimated at a minimum NSR cut-off of $75 per tonne and assume that the Pen II mineral resources would be amenable to processing at the Stall mill.

Qualified Person

The technical and scientific information contained on this website related to the Constancia mine and Rosemont project has been approved by Cashel Meagher, P. Geo, Hudbay’s Senior Vice President and Chief Operating Officer. The technical and scientific information related to the company’s other material mineral projects contained on this website has been approved by Olivier Tavchandjian, P. Geo, Hudbay’s Vice-President Exploration and Geology. Messrs. Meagher and Tavchandjian are qualified persons pursuant to NI 43 101. For a description of the key assumptions, parameters and methods used to estimate mineral reserves and resources at Hudbay’s material properties, as well as data verification procedures and a general discussion of the extent to which the estimates of scientific and technical information may be affected by any known environmental, permitting, legal title, taxation, sociopolitical, marketing or other relevant factors, please see the technical reports for the company’s material properties as filed by Hudbay on SEDAR at www.sedar.com.