Yaurichocha Mine

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

As of December 31, 2018

Contribution
to Total Revenue
Revenue Mix
By Metal in 2018
Zinc Equivalent Pounds
Produced in 2018 (000s)
157,151
All-in-Sustaining Cost
(per zinc equivalent pound sold)
$0.86

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)
Zinc Eq Production (000’s) - guidance for 2020 208,328 - 231,476 pounds
Cash Costs - guidance for 2020 $0.46/pound sold
AISC - guidance for 2020 $0.77/pound sold

Reserves & Resources

On December 19, 2019, the Company released an updated NI 43-101 compliant reserve and resource estimate for the Yauricocha Mine, completed by SRK Consulting Inc. of Vancouver, Canada. The updated Reserve and Resource Estimate will be filed in January, 2020.

Category Tonnes
(x1000)
Ag
(g/t)
Cu
(%)
Pb
(%)
Zn
(%)
Au
(g/t)
ZnEq
(%)
ZnEq
(M lb)
Reserves
Proven 2,665 52.57 1.26 0.95 3.23 0.58 7.65 450
Probable 5,775 43.69 1.07 0.70 3.00 0.47 6.66 847
Proven & Probable 8,439 46.49 1.13 0.78 3.07 0.50 6.97 1,297
Resources
Measured 3,662 65.8 1.3 1.2 3.5 0.7 8.48 685
Indicated 8,989 45.6 1.3 0.7 2.8 0.6 6.97 1,382
Measured & Indicated 12,651 51.5 1.3 0.9 3.0 0.6 7.41 2,067
Inferred 6,501 39.1 1.5 0.6 1.7 0.5 6.11 876

Notes:

  • The effective date of the mineral reserve and resource estimate is October 31, 2019.
  • Details of the estimate are provided in the Company’s December 19, 2019 press release and within a NI 43-101 compliant technical report filed on SEDAR on February 3, 2020. Zinc equivalency is based on the following metal price assumptions: US$15.95/oz Ag, US$2.94/lb Cu, US$0.95/lb Pb, US$1.24 Zn and US$1,303/oz Au. Metallurgical recovery assumptions are variable between mineralization types, and are based on Yauricocha actual plant data for 2019. The average is (where recovered) 76.4% Ag, 80.4% Cu, 88.6% Pb, 89.2% Zn, 17.2% Au. The equivalency expression is designed to present an in-situ zinc equivalent, considering the recovered value of the other metals expressed in the value of zinc percent.
    The equation is: ZnEq = ((Ag*Ag$*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