Yauricocha Mine

Yauricocha is our flagship operation with over 70 years of continuous production

As of December 31, 2020

Contribution
to Total Revenue
Revenue Mix
By Metal in 2020
Copper Equivalent Pounds
Produced in 2020 (000s)
75,079
All-in-Sustaining Cost
(per copper equivalent pound sold) in 2020
$2.11

Quick Facts

Location Peru
Ownership 82%
Type of Mine Underground
Mining Methodology Sub-level caving, cut and fill
Processing Method Crushing and grinding, floatation
Milling/Processing Capacity 3,150
Number of Employees & Contractors 759 (FT), 1,577 (Contract)
Copper Eq Production (000’s) Lbs - guidance for 2021 79,300 - 85,600
Cash Costs - guidance for 2021 $0.96 - $1.03
AISC - guidance for 2021 $1.89 - $1.98

Reserves & Resources

On November 18, 2019, the Company released details of an updated Resource Estimate for the Yauricocha Mine. An updated NI 43-101 Technical Report, completed by SRK Consulting Inc. of Vancouver, Canada, will be filed within 45 days.

Category Tonnes
(x1000)
Ag
(g/t)
Cu
(%)
Pb
(%)
Zn
(%)
Fe
(%)
Au
(g/t)
ZnEq
(%)
ZnEq
(M lb)
Resources
Measured 4,904 55.8 1.1 0.8 2.6 - 0.6 6.71 725.2
Indicated 11,020 38.4 1.2 0.5 2.1 - 0.50 5.77 1,403.0
Measured & Indicated 15,924 43.8 1.2 0.6 2.2 - 0.5 6.06 2,128.2
Inferred 11,633 27.5 1.40 0.31 0.95 - 0.45 4.75 1,219

Notes:

  • A PEA press release was filed on November 18, 2020. In accordance with NI 43 101 Rules the Yauricocha Mine Mineral Reserves are not valid after its issuance and have been removed. They will be reported as part of an NI 43-101 Mineral Reserve Report or Prefeasibility Study expected in early Q2 2021
  • The effective date of the mineral resource estimate is June 30, 2020.
  • Details of the estimate are provided in the Company’s November 18, 2019 press release and a NI 43-101 technical report filed on SEDAR in December 2020. Zinc equivalency is based on the following metal price assumptions: US$18.24/oz Ag, US$3.05/lb Cu, US$0.91/lb Pb, US$1.06 Zn and US$1,502/oz Au. Metallurgical recovery assumptions are variable between mineralization types, and are based on Yauricocha actual plant data for 2019. The average is (where recovered) 76% Ag, 75% Cu, 89% Pb, 89% Zn, 22% Au. The equivalency expression is designed to present an in-situ zinc equivalent, considering the recovered value of the other metals expressed in the value of zinc percent.
    The equation is: ZnEq = ((Ag*Ag$*Agrec)+(Cu*Cu$*Curec)+(Pb*Pb$*Pbrec)+(Zn*Zn$*Znrec)+(Au*Au$*Aurec)) / (Zn$*Znrec).
  • Measured and Indicated Resources include Proven and Probable Reserves.
  • Mineral resources that are not mineral reserves do not have demonstrated economic viability.

Through its wholly owned subsidiary, Dia Bras Peru S.A.C., Sierra Metals acquired 82% of Minera Corona, S.A. ("Corona") in May of 2011. Corona owns 100% of the Yauricocha Mine. Yauricocha, is an underground mine located in western central Peru in the Yauyos province, approximately 12 km west of the Continental Divide. The Yauricocha property covers 18,778 hectares that straddle a 20 km strike length of the prolific Yauricocha fault, a major ore controlling structure in this part of western central Peru. The mine is at an average altitude of 4,600 meters and has been producing for more than 68 years. Ore is processed at the on-site Chumpe plant using a combination of crushing, grinding and flotation and is permitted to produce at a rate of 3,150 tonnes per day, which is expected to increase to 3,600 tonnes per day during 2019 upon receipt of the ITS permit. A preliminary economic assessment released in June 2018, studies increasing production to 5,500 tonnes per day in 2021.

The ore is treated in two separate circuits and is extracted from three different types of deposits which include the following:

  • A polymetallic deposit, containing silver, lead, zinc, copper, and gold
  • A lead oxide deposit, containing lead, silver and gold
  • A copper oxide deposit, containing copper, silver, lead and gold

Exploration

Peru is one of the most prolific polymetallic producing regions of the world. Sierra Metals controls a large area of prospective claims, exceeding 50,000 hectares of mining claims within the country.

The exploration program has the following goals:

  • Brownfield programs within and close to existing mines to exploit near mine targets that can be converted into resources and reserves and brought into the existing mine plans within a shorter period of time
  • Developing a pipeline of open pit and underground opportunities through a district scale study that incorporates various geological data layers, historical drill hole and mine data