Quebrada Blanca has a complex magmatic and hydrothermal history that includes a polyphase intrusive complex, multiple cross-cutting breccia facies, and at least three separate hydrothermal stages.

The initial intrusive phase consisted of Paleozoic quartz monzonite to granodiorite and diorite. These rocks were in turn intruded by pre- to syn-mineral feldspar porphyries and syn-mineral hydrothermal breccias that were emplaced along northeast–north–northeast- trending faults. The hydrothermal breccia is interpreted to be a single event, with textural and hydrothermal facies representing different energy conditions and hydrothermal zonation.

The deposit is divided into four domains or blocks, with the south and east blocks containing most of the mineralization. The blocks have different oxidation, alteration, and lithology characteristics. The western block, limited by a major northwest fault, the DDH-49 fault, is characterised by alteration features indicative of deeper parts of a porphyry system, and has been well drilled out. The eastern block has alteration facies consistent with the upper levels of a porphyry system, and is not as well drilled out. The northeastern-most block shows intermediate- level alteration features and has the least drill information.

Mineralization consists of supergene (chalcocite and, to a lesser degree, copper oxides such as atacamite, cuprite, and locally brochantite) and hypogene (chalcopyrite, bornite, molybdenite) mineralization.

Supergene Zone.
Secondary mineralization appears to be preferentially concentrated close to structures and more permeable rocks. The leach cap varies from about 7–200 m in thickness, whereas the thickness of the secondary copper zone ranges from 10–200 m. Continuous supergene copper mineralization has been traced over a 2.5 x 1.5 km area. The lower portions of the secondary enrichment zone transition into primary copper mineralization, resulting in a mixed low-grade ore type that was processed through runof-mine (ROM) dump leaching.

Hypogene Zone.
In the hypogene environment, mineralization occurs mainly as disseminated, veinlet-like and breccia cement mineralization following an east–northeast-trending area of about 2 x 5 km that is hosted within the Paleozoic quartz- monzonite to granodiorite, feldspar porphyry intrusions, and breccias. Drill holes have intersected mineralization over 1,000 m vertical depth in the hypogene zone.

The porphyry-style mineralization at Quebrada Blanca is considered to be typical of an Andean porphyry copper–molybdenum deposit. Common features of this subset of porphyry-style deposits include:

- Large zones (>10 km2) of hydrothermally altered rocks that commonly grade from a central potassic core to peripheral phyllic-, argillic-, and propylitic-altered zones;

- Mineralization is generally low grade and consists of disseminated, fracture, veinlet, and quartz stock-work controlled sulphide mineralization. Deposit boundaries are determined by economic factors that outline ore zones within larger areas of lowgrade, concentrically-zoned mineralization;

- Mineralization is commonly zoned with a chalcopyrite–bornite–molybdenite core and peripheral chalcopyrite–pyrite and pyrite zones;

- The effects of surface oxidation commonly modify porphyry deposits in weathered environments. Low pH meteoric waters generated by the oxidation of iron sulphides will leach copper from hypogene copper sulphides and form oxide copper minerals such as malachite, chrysocolla, and brochantite, and redeposit copper as secondary chalcocite and covellite immediately below the water table in flat tabular zones of supergene enrichment.

The initial open pit mine at Quebrada Blanca (the Quebrada Blanca Phase 1 operation or QB1) commenced operation in 1994, exploiting supergene copper mineralization. To date, operations at the mine have used a heap leach and dump leach and solvent extraction/electrowinning (SX/EW) process. The supergene ore is now depleted and mining operations ceased in October 2018; however, the SX/EW plant will continue to produce cathodes throughout 2019 and 2020 from existing supergene leaching pads.


The Quebrada Blanca Phase 2 project (QB2) is planned to exploit hypogene mineralization below the supergene mineralization mined in QB1. The environmental impact assessment (EIA) for QB2 was prepared in 2016, and approved by the Chilean environmental authorities in August 2018. The Teck board has approved the QB2 project for full construction, with first production targeted for the second half of 2021.

Mining operations will continue to use open pit methods, and conventional truck-andshovel operations. From an operational standpoint, QB2 represents a continuation of the existing supergene mine activities; however, there are significant differences between the two operations, such as the significant increase in the ultimate pit depth and width, the change in rock type from enriched supergene to hypogene, and increases in the mining extraction rate.

Teck prepared two mine plans for the Project: -- Base Case that includes only Measured and Indicated (MI) Mineral Resources and support reporting of Mineral Reserves. This plan schedules a total of 1.4 Bt of mill feed and 0.56 Bt of waste rock over a mine life of about 28 years at a 0.41:1 strip ratio.

- Sanction Case that includes Measured, Indicated, and Inferred (MII) Mineral Resources. The Sanction Case optimization, mine planning and financial analysis considered realistic mining conditions and the likely continuity of the ore body. The plan, used for Project evaluation purposes, generates a total mill feed of 1.4 Bt and 0.909 Bt of waste rock over a 28-year mine life at a 0.65:1 strip ratio.

The conventional open pit supergene mining operation was completed in October 2018. The existing QB1 mining fleet will be used in pre- production and early works activities related to QB2, including the mass excavation required for the concentrator site, and mass earthworks associated with construction of the starter dam for the TMF.

To generate the required slope designs, the pit was subdivided into five geotechnical zones, each with different design inter-ramp slope angles.

The pit design criteria for each of the Base Case and Sanction Case are summarized:
- Ramp width 40 m - with a design grade of 10%;
- Minimum bench operational width - 70 m;
- Bench face angle - 65°;
- Inter-ramp angle - Varies from 30° to 44° depending on geotechnical zone;
- Bench height - 15 m;
- Berm width - typically 8 m, but adjusted for inter-ramp angle where necessary;
- Inter-ramp slope height - 150 m;
- Geotechnical berm width 30 m (haulage ramps can replace geotechnical berms).

Mining Equipment.
Equipment requirements are identical for the Base Case and the Sanction Case. The mine design and costing for the Base Case and Sanction Case currently assume the use of 291 t haulage trucks; however, actual equipment selection will be made based on pricing and performance considerations following commercial discussions with several equipment suppliers.

Loading.
The primary loading units would be 58.1 m³ ultra-class electric rope shovels, which are well-matched (three-pass loading) to 291 t haulage trucks. The existing 27 m³ hydraulic shovel fleet (Komatsu PC5500) would continue to remain in service, given the units’ availability and remaining available service lives. The existing 18 m³ front-end loader fleet (Komatsu WA1200-6) would continue to serve the mine and would be replaced as necessary to ensure two units are available at all times to serve the mine.

Haulage.
Eleven Komatsu 730E haul trucks and six Komatsu 830E haul trucks would remain from the supergene operations and would be used by the QB2 operations until reaching their expected service lifespan. As mine production rates will surpass the existing fleet capacity, 291 t capacity haul trucks (Komatsu 930E-4SE) will be purchased as necessary.

At the peak, the haulage fleet would require 34 haul trucks.

Support Equipment.
At peak of operations, this will see equipment requirements will be four tracked dozers, four wheeled dozers, seven graders, five water trucks, one tracked excavator, three cable reelers and two mobile generators.

The primary crushing facility would contain a single gyratory crusher with a double-sided dump pocket for the mine haulage trucks. The crusher would be serviced by a mobile maintenance crane and the crusher station would be open on the discharge side with a mechanically stabilized earth (MSE) type retaining wall. The area would contain the following major equipment and structures:
- One 1,000 kW, 1,600 by 3,000 mm (63 by 118 inch) gyratory type crusher;
- One 3,150 mm wide by 12 m long variable speed apron feeder with hydraulic drive and two 185 kW motors;
- One hydraulic rock breaker;
- One dust suppression system.

The coarse ore conveyor system would consist of two overland conveyors to transport the crushed ore from the primary crusher to the coarse ore stockpile. The area would contain the following major equipment and structures:
- One 260 m long by 1,830 mm wide steel cord, 10,000 t/h capacity coarse ore conveyor no. 1;
- One 1,216 m long by 1,830 mm wide steel cord, 10,000 t/h capacity coarse ore conveyor no. 2.

The concentrator facility would contain grinding mills, cyclone feed pumps, and cyclone clusters. The grinding equipment would be housed in a steel building. The area would contain the following major equipment and structures:

- Two 12.2 m diameter by 6.7 m effective grinding length (EGL), 24 MW SAG mills, driven by gearless type drives, each with a discharge trommel screen (6.2 m in diameter by 5.2 m long);
- Four 7.9 m diameter by 12.8 m flange-to- flange length, 16.4 MW ball mills, driven by gearless type drives;
- Four cyclone feed slurry pumps, rated at 8,817 m3/h and 2,000 kW, with adjustable frequency drives;
- Four cyclone clusters with eleven operating and three standby 838 mm diameter cyclones in each cluster;
- A 102 m wide by 114 m long by 47 m high steel grinding building.

Pebble crushing facility would consist of the pebble transfer conveyors, storage bins, feeders, and crushers. The crushers would be housed in an open steel building. The area would contain the following major equipment and structures:

- One 1,067 mm wide, 169 m long pebble collecting conveyor with 185 kW motor and AFD;
- One 914 mm wide, 87 m long pebble transfer conveyor with 150 kW motor;
- One 914 mm wide, 140 m long crushed pebble collecting conveyor with 100 kW motor;
- One 914 mm wide, 44 m long crushed pebble conveyor with 45 kW motor and AFD;
- Two 750 kW cone crushers.

Flotation and Regrind area would contain the following major equipment and structures:
- Fourteen 600 m3 bulk rougher flotation tank cells (two rows of seven cells);
- Two bulk rougher regrind cyclone clusters;
- Two 3,500 kW high-intensity grinding (HIG) regrind mills;
- Eight bulk first cleaner staged flotation reactor (SFR) “SFR-2200” cells (two rows of four cells);
- Ten bulk cleaner/scavenger SFR “SFR-2200” cells (two rows of five cells);
- Five bulk second cleaner SFR “SFR-1300” cells.

Concentrate thickening facility would consist of the bulk concentrate and copper concentrate thickeners. The area would contain the following major equipment and structures:
- One 43 m diameter bulk conventional concentrate thickener with rakes and underflow pumps;
- One 43 m diameter copper conventional concentrate thickener with rakes and underflow pumps.

Molybdenum plant facility would consist of the molybdenum rougher, first cleaner, second cleaner, and third cleaner flotation and regrind equipment, as well as the molybdenum concentrate thickener, filter, dryer and packaging equipment. The area would contain the following major equipment and structures:

• Seven 42.5 m3 molybdenum rougher cells (one row of seven);
- One 300 kW vertical molybdenum regrind mill; - Six 14.2 m3 molybdenum first cleaners (one row of six cells);
- One 3 m diameter second cleaner column cell; - Two 1.5 m diameter third cleaner column cells;
- One molybdenum flotation cell exhaust gas scrubber with fan;
- One 15 m diameter molybdenum concentrate thickener with rakes and underflow pumps;
- One automated pressure filter, one heated-oil screw dryer, a 42 t capacity dry molybdenum storage bin, and a bulk bag molybdenum packaging system;
- One molybdenum concentrate dryer exhaust gas scrubber with fan.

The reagent facility would consist of equipment and systems for mixing, storing, and distributing the various reagents to their points of use.

Two tailings thickeners and their associated equipment would comprise the tailings thickening area.

Power for the process plant will be sourced from the Chilean grid. Process make-up water will be from desalinated water with reclaim water from the TMF.