Cañariaco Norte Deposit, Peru

According to the PEA, the Cañariaco Norte project carries an initial capital cost estimate of $1.04bn.

It is expected to produce 173 million pounds (Mlb) (78,543 tonnes) of copper, 31,395 ounces (oz) of gold, and 703,588oz of silver over an initial mine life of 28 years.

The results of an optimised PEA are expected to be published in the fourth quarter of 2023.

Cañariaco Location and Site Details

The Cañariaco Project is located approximately 700km northwest of Lima within the Province of Ferreñafe, in the Region/Department of Lambayeque.

The location is approximately 120km northeast of the city of Chiclayo.

The Cañariaco Project consists of 15 concessions covering a total area of 10,190 hectares (ha). The project area region has an elevation ranging between 2,200 and 3,600 metres above sea level (masl).

The project can be accessed by a road from Lima via Chiclayo through the Pan-American Highway (700km) or via commercial flights.

According to the PEA, the project has adequate land available for tailings disposal, mine waste disposal, and other related infrastructure.

Ownership and Exploration History

Copper was discovered at the deposit during a regional stream sediment sampling programme conducted from 1967 to 1970 by INGEMMET and the British Geological Survey team.

In 1994, the area was optioned by Placer Dome Exploration from the Peruvian Government, but it was reverted to the Peruvian Government as the option was not exercised.

Billiton Exploration and Mining Perú took an option in 1999 from the Peruvian Government. The following work programme included geological mapping, soil and rock chip sampling, IP/resistivity and ground magnetic geophysical surveys among others.

The option was dropped in 2000 and the Peruvian Government received the property again.

Subsequently, the property was put to auction in which Exploraciones Milenio (later CCPSA), a Peruvian subsidiary of Candente Copper, acquired 100% ownership in February 2002.

The project’s mineral resource estimate was prepared for Candente in 2004. It was updated in 2006, 2008, 2010, and in 2022.

Candente rebranded itself as Alta Copper in May 2023.

Cañariaco Norte Geology and Mineralisation

A multiphase intrusive-breccia complex of approximately 1.1km wide and 1.7km in strike extent hosts the Cañariaco Norte deposit.

The deposit was drill tested up to 770m and it is open at depth.

The northwest-to-southeast and northeast-to-southwest trending faults control the shape and position of intrusive, breccia, and dyke units.

The main minerals present in the deposit are chalcopyrite, covellite, chalcocite, and enargite. The deposit also has bornite, digenite, tennantite, and trace tetrahedrite in minor quantities. Copper sulphide minerals are associated with other sulphide gangue minerals and pyrite.

The biotite-feldspar porphyry and polymictic breccia units host the highest copper grades greater than 0.5%. The intermediate copper grades, 0.35% to 0.5%, are present in hydrothermal breccia and coarse quartz porphyry; and the lowest grades, 0.2% to 0.35%, are found in tourmaline breccias, volcanic host rocks, and crowded quartz-feldspar porphyry.

Mineral Resource Estimate for Cañariaco Norte Deposit

According to the 2022 PEA, the total mineral resources (measured + indicated) for Cañariaco Norte, at a 0.15% Cu Cut-off Grade, are 1,094.2Mt at a grading of 0.42% copper equivalent, containing 9.29Blb copper at a grading of 0.39%, 2.14Moz gold at a grading of 0.06g/t, and 59.43Moz silver at a grading of 1.7g/t.

Inferred mineral resources stand at 410.6Mt at a grading of 0.32% copper equivalent, containing 2.66Blb copper at a grading of 0.29%, 0.55Moz gold at a grading of 0.04g/t, and 18.09Moz silver at a grading of 1.4g/t.

Mining Method and Ore Processing

Conventional open-pit mining methods and equipment will be used to mine ore from the copper-gold-silver project.

The mill feed and waste from the mine will undergo drilling, blasting, and then will be loaded with the help of hydraulic face shovels and front-end loaders. The haul trucks will deliver above haul cut-off mineralised material to the material crusher and waste will be disposed to the planned dry-stack waste rock and tailings storage facility (WSF) or a waste crusher during production.

The crushed waste will be transferred to the plant site and it will be combined with dewatered tails and then stacked at the waste storage facility. The mining capacity will be 54.6Mt/annum at peak.

The processing plant, a conventional copper concentrator, will be developed in two phases- Phase I with 14.6Mt/annum nominal throughput (first six production years) and Phase II when the production will be doubled.

The Run of Mine (ROM) mill feed and waste rock will undergo primary crushing and then it will be transferred to tripper conveyor and separate stockpiles.

Mill feed material grinding will feature SAG mill, pebble recycle crusher, and ball mill in a closed circuit with hydrocyclones.

The project will use three-stage cleaner flotation of regrind concentrate to produce final concentrate grade and cleaner–scavenger flotation to maximise copper recovery.

Power Supply

The site will receive electricity via a 220kV overhead transmission line connected to a local Carhuaquero utility substation, which is located 55km from the mine site.

The voltage of the transmission line will be stepped down to 25kV from 220kV at the main site substation.

For Phase I, the total load is anticipated as 119MW. The power requirement will increase to 171MW in Phase II.

The diesel-generating sets will supply electricity to the water treatment plant.

Contractors Involved

Ausenco Engineering Canada, a global consulting and mining solutions provider, prepared a technical report based on the 2022 PEA results. Hemmera Environchem, DKT Geosolutions and AGP Mining Consultants also supported the preparation of the PEA.

Ausenco also completed Desk Top Conceptual Study on the project in June 2021.

Yaku Consultores was engaged to conduct and continue previous baseline studies at the Cañariaco Project in March 2021, while Australian mining consultant firm Whittle Consulting was responsible for Enterprise Optimization (EO) of the project.

Candente Copper hired AMEC Americas and global consulting firm Knight Piesold for certain aspects of a more detailed mining study from April 2011 to June 2013.