Mexico Reserves (2020)
Securities and Exchange Commission (SEC) Proven and Probable (P&P) Industry Guide 7 Reserve Estimates
As of December 31, 2020, our estimate of Proven and Probable (P&P) reserves was:
|Au oz||Ag oz||AuEq oz||Cu
|Don David Gold Mine|
|Arista Mine Total||2,266,200||2.16||121||3.58||156,300||8,825,800||260,800||0.4||1.6||4.4|
|Mirador Mine Total||62,300||0.77||357||5.00||1,600||715,900||10,000|
|Don David Gold Mine Total||2,328,500||2.11||127||3.62||157,900||9,541,700||270,800|
Notes to the 2020 P&P reserves:
- Metal prices used for P&P reserves were $1,477 per ounce of gold, $17.47 per ounce of silver, $2.83 per pound of copper, $0.92 per pound of lead and $1.17 per pound of zinc. These prices reflect the three-year trailing average prices for gold, silver, copper, lead and zinc.
- Precious metal AuEq is 84.54:1 using gold and silver only to calculate gold equivalencies.
- A breakeven Net Smelter Return (“NSR”) cutoff grade of $77 per tonne was used for estimations of P&P reserves at the Arista Mine. The term “cutoff grade” means the lowest NSR value considered economic to process.
- No appreciable amounts of base metals are present in the veins identified to-date at the Mirador Mine at the Alta Gracia project. A breakeven cutoff grade of 2.33 g/t AuEq was used for proven and probable reserves at the Mirador Mine using gold and silver only to calculate gold equivalencies.
- Mining, processing, energy, administrative and smelting/refining costs were based on 2020 actual costs for the Don David Gold Mine.
- Arista Mine metallurgical recovery assumptions used were 76% for gold, 92% for silver, 80% for copper, 79% for lead and 80% for zinc. Mirador Mine metallurgical recovery assumptions used were 85% for gold and 72% for silver. These recoveries reflect 2020 actual average recoveries for the Aguila and Alta Gracia projects.
- P&P reserves are diluted and factored for expected mining recovery.
- Minimum mining width for P&P reserves is 1.5 meters for the Arista and Mirador underground mines.
- Figures in tables are rounded to reflect estimate precision and small differences generated by rounding are not material to estimates.