Minera Tres Valles mining complex (MTV) is a Cu-Ag stratabound, manto-type deposit.

The MTV Project consists of two main deposit areas about 5km apart. The Don Gabriel area hosts the Don Gabriel Manto and Don Gabriel Vein deposits. The Papomono (“PPM”) area consists of seven known deposits: Massivo, Cumbre, Mantos Connection, PPM South, Mantos North, PPM North, and Epithermal.

Papomono
The dominant sulphides in the deposit are in decreasing order: chalcocite-covelite (~85%), bornite (~6%), enargite (~5%) and chalcopyrite (~4%). It is important to mention that the bulk of the chalcocite at MTV is hypogene. Very few parts were observed with supergene chalcocite. In places where intense fracturing and faulting occurs, the action of oxidizing agents generates oxide copper minerals: chrysocolla, malachite, brochantite and atacamite. For this reason, the traditional vertical zonation of oxides on top and sulphides in deeper parts are not identified in Papomono and the main oxide zones are related to more fractured zones, sometimes deeper than preserved sulphides.

The most common deposit geometry is the manto-type (stratiform). The individual “mantos” have a thickness that ranges from 2 to 50m, up to 500m strike extension and length along dip reaching 600m. Examples of this type of deposit geometry are the PPM South, Mantos Connection, and the Mantos North deposit. The other common geometry is vein-type, with a thickness between 2 and 15m, strike length from 100 to 420m and 100 to 250m deep. Dip angle is generally steep, between 80° and 90° to the west. There are also sets of tens of cm-thick N-S veins dipping 55° to the east. These sets of veins occur in clusters of 10 to 30 narrow, around 50m long, massive chalcocite veins.

One specific and important geometry is observed in only one deposit, PPM Massivo. It is a complex geometry which resulted from the intersection of at least three different mineralization controls in the same area: the Papomono Fault system, the favorable strata (mantos) and the N-S set of small veins dipping east. The resulting geometry is roughly an inverse triangle or a truncated rhomb shape, which has 440m strike, up to 190m wide and 190m high.

Finally, there is a cylinder-shape geometry related to the intrusive plug of Cumbre. This deposit is vertical, with at least 400m deep (310m from the bottom of exploited Cumbre pit) and an average diameter of 180m. A near surface oxide mineralized zone was hosted in the upper part of intrusive as well in the contact zones with volcanic to volcanoclastic rocks of the Quebrada Marquesa Formation and was already exploited by open pit. Deeper zones in Cumbre present disseminated chalcocite and bornite mineralization.

Don Gabriel
The mineral deposit of Don Gabriel is formed of two main zones:
- An upper deposit of “manto” type, medium copper grade, with a set of stratabound disseminated, fine chalcocite, mineralization approximately 100m thick, dipping 30° SSW.
- A lower deposit, vein-shaped (straight-tabular), sub-vertically oriented N45°W, with intense strong to spotty mineralization or veinlets type (stockwork or sheeted veinlets), high copper grade, with chalcocite, digenite and some bornite.

Whereas the first type is hosted mainly in andesite amygdaloidal levels, the second type has medium to coarse porphyritic andesite and/or dioritic to microdioritic dikes as host rock, which underlies the level of coarse sandstone. The layers of sandstone serve as a guide-level separating the two main units. It is used as a sharp limit between the two geological models, Don Gabriel Mantos and Don Gabriel Veins.

The vertical-tabular mineralization seems to be intimately linked to the presence of dioritic dikes, which, in turn, are related to an intrusive stock to the W and SW, and outcrops at the bottom of the ravine near the mineral deposit. Such stock was also intercepted by several drill holes a little further to the east. Those dikes found in such drill holes may also be observed in the mine’s roads cut, as a 2 to 10m-thick dike swarm, which follows the same N45-50°W direction of the mineralization.

Considering the clear relationship between the vein shape mineralization and such dikes, it is possible to speculate the presence of a metasomatic component in its genesis, despite no distinctive skarn mineral being observed, only epidote and chlorite. Another possibility is that the dioritic magma emplaced areas of structural weakness, also employed by the mineralizing fluids immediately after the igneous siting (tardi- magmatic event). In some areas, mineralization zones are also observed, with similar characteristics to the “mantos”, chalcocite disseminated mineralization with pervasive albite, which makes it possible to glimpse the potential presence of stratabound deposits, but not stratiforms, as a set of parallel veins restricted to favorable stratigraphic levels (e.g. mineral deposits El Soldado or El Espino). Another aspect worth mentioning is the common presence of veins or disseminated hematite surrounding the best mineral grade sectors.

Tres Valles complex comprises two main deposits: Papomono (underground) and Don Gabriel (open pit). The mine is currently operating and producing high-grade copper cathode.

Don Gabriel Manto
Don Gabriel Manto commenced the exploitation in 2012 using open pit method and, after a period of suspension from 2014 to 2016, it is currently in the ramp-up phase reaching its maximum production capacity (about 2.4 kt/d) at the beginning of 2019. The base case mine plan is based on Mineral Reserves of 5.168 million tonnes at 0.81% total copper (TCu) and is expected to produce approximately 14 million pounds of copper per year over a six-year reserve life.

Papomono Masivo
A sector of Papomono Masivo is under exploitation using front caving method (FC) and is planned to continue until before the start-up of the inclined block caving operation. The mine plan considers reserves of 3.07 million tonnes at 1.5% TCu and during its useful life of about 5 years will produce the order of 12.5 million pounds of copper per year.

The construction and development of Papomono Masivo is expected to be completed in the fourth quarter of 2021 with initial ore production beginning during the third quarter of 2021.

Papomono Masivo uses a combination of front caving and inclined block caving mining methods, based on financial considerations, deposit geometry and geotechnical characteristics.

Three dominant fault systems are present:
• Manquehua fault: This structure strikes N20°W and dips to the east (60° to 85°).
• Papomono fault system: N40°W striking structure (320°), with a variable dip from 60° to 90° to the west.
• East-west faults: Approximately 1 m wide east-west to northeast-striking structures, with subvertical dips.

A work plan was derived, based on an investment limit concept: Project initial infrastructure (civil and mining) whose costs should not exceed US$ 10 million as the initial capital cost, excluding mobile equipment and attain a production capacity of 2,000 t/d.

The base of the Papomono Masivo inclined block caving layout was a 10 x 10 x 10 m operational grid with 130 draw points and five levels.

The ventilation strategy for the inclined block cave maintains the existing fresh air intake from the North and South portals. Vitiated air will be exhausted through a new adit that will be located at the “Narbona” tunnel.

The material handling system assumes mining by means of 3.5 yd3 load-haul-dump (LHD) equipment, conveying ore from the mining points to ore passes that will be located in the main haulage tunnel.

2018 PEA Mine Plan
The company has developed a PEA mine plan for the exploitation of mining zones within the Mineral Resources on the property, which includes Measured, Indicated and Inferred Mineral Resources.

The alternative mine development option in the 2018 PEA Mine Plan considers a conceptual mine plan with significantly more zones being developed and mined using different mining methods from the base case. The PEA includes a conceptual mine plan for the Don Gabriel Mantos using open pit methods, and a conceptual mine plan for the PPM Masivo deposit. The following additional zones for the two deposits are included in the 2018 PEA Mine Plan, with the mining method identified for each:
• Don Gabriel Deposit: Don Gabriel Vetas (Sub Level Stoping)
• Papomono Deposit: PPM Norte (Open Pit), Manto Norte (Front Cave), Epitermal (Sub Level Stoping), PPM Cumbre (Open pit), PPM Mantos Conexión (Front Caving), PPM Sur (Sub Level Caving).

These additional mining zones will require additional drilling and engineering work to increase the confidence level. The PEA Case illustrates the property-wide production potential for MTV.

Minera Tres Valles’ process starts by receiving ore from both of the company’s own mines as well as third parties at the main Ore Stockyard. The different batches are loaded into a primary jaw crusher that reduces the rock to fragments smaller than < 90 mm. From this stage, the ore is sent to a standard cone type secondary crusher, which produces fragments no bigger than < 25 mm (1”).

This material is sent to the tertiary crusher, where the grain size is < 14 mm. Finally, the ore is sent to the quaternary crusher, which reduces the size of the stacking ore to < 6 mm (or ¼”).

In the fourth quarter of 2019, the configuration of the crusher was modified to a three-stage configuration where either the tertiary or quaternary crusher is utilized in the circuit depending on the type of ore being put through the SX-EW plant in order to optimize grind size. This application is expected to continue going forward producing efficiencies to the operation.

The mine is currently operating and producing high-grade copper cathode. MTV has a crushing and processing plant with nameplate capacity of 7,000 and 6,000 tonnes per day, respectively. The plant is designed to produce up to 18,500 tonnes per annum of LME Grade 99.999% copper cathodes.

MTV extracts mineralized material from the Papomono (underground) and Don Gabriel (open pit) mines together with other ancillary deposits and receives mineralized material from third parties at the run-of-mine stockpile. Mineralized material is crushed into fragments of which 80% are smaller than 6mm. The crushed material is agglomerated with a sulfuric acid solution to start the leaching process. Beginning in June 2019, sodium chloride ("Salt Leach") was introduced at the agglomerator stage as detailed in the NI 43-101 compliant independent technical report released in March 2018. Since June 2019, increasing doses of sodium chloride have been added at the agglomerator stage. Prior to the impl ........