Name: Constancia mine.

Location: The mine is located in the south-eastern Andes of Peru, in the province of Chumbivilcas.

Mine Owner/s: Hudbay Minerals.

Brief History: Hudbay acquired the Constancia project in 2011 and completed construction of the mine in the fourth quarter of 2014, reaching commercial production in the second quarter of 2015. The mine reached full and steady-state production in the second half of 2015. Hudbay has since been focused on optimising the operation.

Brief Description: Constancia is an openpit mine comprising the Constancia and Pampacancha deposits.

Primary metals: Copper.

Secondary metals: Molybdenum, silver.

Geology/Mineralisation: The Constancia deposit is a porphyry copper/molybdenum/silver system, which includes copper-bearing skarn mineralisation. This type of mineralisation is common in the Yauri-Andahuaylas metallogenic belt, where several porphyry copper/molybdenum/gold prospects have been described but not exploited.

The main porphyry deposits in the belt include Antapaccay and Quechua. Several other porphyry prospects are also being explored in the district.

The Pampacancha deposit is a copper/molybdenum/silver porphyry related skarn system, with copper-bearing skarn mineralisation. This type of mineralisation is common in the Yauri-Andahuaylas metallogenic belt.

Reserves: Total proven and probable reserves as at January 1, 2018, were estimated at 568.6-million tonnes grading 0.32% copper, 99 g/t molybdenum, 0.058 g/t gold and 3.07 g/t silver.

Resources: Total measured and indicated resources as at January 1, 2018, were estimated at 373.3-million tonnes grading 0.21% copper, 56 g/t molybdenum, gold 0.041 g/t gold and 2.28 g/t silver. Inferred resources were estimated at 64.1-million grading 0.22% copper, 59 g/t molybdenum, 0.052 g/t gold and 2.05 g/t silver.
 

Mining Method: The Constancia mine is a traditional openpit operation using conventional truck-and-shovel mining.

Major Infrastructure and Equipment: Hudbay’s processing plant at Constancia has a nominal throughput capacity of 90 000 t/d. The primary crusher, belt conveyors, thickeners, tanks, flotation cells, mills and various other types of equipment are designed and built to be open to the environment. The tailings are pumped to the tailings management facility for storage, and water is returned through parallel piping to the process plant for reuse.

The facility has been designed to store 600-million tonnes of tailings, with a final design elevation of 4 186 m above sea level.

The potentially acid- and non-acid-generating waste rock facilities (WRF) are located in the Cunahuiri valley, east of the Constancia pit, and provide storage for 581-million tonnes. The facilities receive mine waste material from the operation of the Constancia and Pampacancha pits. The facilities include WRF retention and containment ponds.

Prospects: Hudbay completed a twin-hole drill programme in the fourth quarter of 2017 that confirmed the extent of the positive grade bias that has existed since the start of production at Constancia. Hudbay also constructed a new resource model that formed the basis for a new mine plan and technical report for Constancia.

The new technical report assumes that the mining of the high-grade Pampacancha satellite deposit will start in 2019. Hudbay plans to install new equipment in support of efforts to optimise recoveries at the mine.

Contact Details:
Hudbay Minerals
Tel +1 416 362 8181
Fax +1 416 362 7844
Email info@hudbayminerals.com
https://www.hudbayminerals.com