The two main deposits types present on the Don Mario property are exemplified by the copper-dominated UMZ deposit that shows direct association with a large, hosting calcsilicate zone, and the gold-dominated LMZ deposit that occurs beneath the UMZ and shows direct association with shearing focused silicification, calc-silicate, potassic and iron oxide alteration. The LT and CF deposits are similar in style and association to the LMZ but no substantive additional examples of the UMZ style have been identified on the property to date.

Mining and exploration programs to date on the property have shown that the LMZ occurs within a well-developed northwest striking and steeply northeast dipping structural/lithologic corridor that constrains gold-copper-silver mineralization as well as distinctive alteration assemblages. Alteration associated with gold-copper-silver mineralization commonly takes the form of iron carbonate, white mica, biotite, quartz, albite, andalusite, staurolite, garnet, cordierite, gedrite and anthophylllite-cummingtonite that occur in highly strained, steeply dipping mineralized corridors. The current spatial disposition of the LMZ and UMZ deposits may be of structural derivation, with the calc-silicate dominated and synclinally folded UMZ host sequence representing a shearing-associated “flower structure” located structurally above the sheared LMZ (L. Isla Moreno, personal communication, 2015).

The LMZ, LT, and CF gold mineralization is spatially associated with shear zones. On a regional scale, these gold deposits occur in the central parts of regional faults, or shears. They are characterized by silicification of the host rocks and a calc silicate mineral assemblage. The LMZ and CF deposits are proximal to a granitic intrusion, but no such spatial relationship is noted at LT. Shear hosted gold deposits are generally found in greenstone terrains that have greenschist grade metamorphism. Despite the higher metamorphic grade characteristic of the host rocks in the Don Mario district, it is not unreasonable to classify the subject deposits as shear hosted gold deposits that are common in Archean greenstones belts throughout the world (Roberts, 1988).

The copper gold silver UMZ deposit occurs in the hangingwall of the shear zone that hosts the LMZ. It is characterized by a calc silicate mineral assemblage that includes tremolite, talc (serpentine) and magnetite, which, along with the occurrence of a dolomite unit in the rock package, suggests a metamorphosed carbonate replacement or skarn deposit with chalcopyrite and native gold as the economic minerals. The causative intrusive could be the amphibolite dykes

Original workers on the Don Mario property variously characterized mineralization at the Don Mario deposit as being structurally focused, shear zone related or to be of volcanogenic massive sulphide association. As noted above by Wright et al. (2009), alternative views on deposit genesis include skarn association, banded iron formation-hosted structural association, and deformed, syngenetic massive sulphide association,. The deposit was more recently classified by Arce Burgoa (2009) as being a deformed example of the Iron Ore Copper Gold (IOCG) association.

There are four principal mineral deposits on the Don Mario property that have contributed to commercial mining operations to date. The most significant of these are the UMZ and LMZ.

The UMZ forms a prominent, oval shaped, treeless hill that is oriented at approximately 315º, parallel to the regional shear fabric trend of the Cristal Schist Belt. The mineralized zone plunges northwest at approximately 15º.

The UMZ has been divided into 9 main rock types, the most prevalent of which are calcsilicates such as diopside tremolite rock and massive tremolite rock plus dolomite/ophicalcite and talc schist.

The main UMZ calc silicate bearing zone is approximately 500 m long and forms the Cerro Don Mario, which is a ridge approximately 120 m high. This rock package has a maximum horizontal width of approximately 150 m and ranges from 5 m to 100 m thick.

The predominant quartz-biotite rock is characterized by a dark gray, fine grained, moderately foliated siliceous character with a compact granular texture. Aligned biotite grains are disseminated throughout a fine grained quartz groundmass and have not been segregated into laminae. Because the rock lacks micaceous bands, cleavage is poor. Muscovite is present only in trace to locally accessory amounts. The absence of muscovite in the quartz-biotite rock, as well as its absence in other subdivisions of the LMZ, is the single most important feature of the LMZ. This is considered by Orvana to reflect a potassic alteration event in which all original muscovite was replaced by biotite. The contact between quartz-biotite rock and overlying quartz-muscovite-sillimanite schist is defined by a relatively abrupt change in muscovite content from >20% to trace amounts over a distance of 1-3 meters. When quartzbiotite rock is present along the basal portion of the LMZ, a similar gradational contact with the footwall schist is present. The LMZ has been divided into 4 main rock types dominated by quartz-biotite-garnet rock and massive magnetite rock.

Mineralization characterizing the CF and LT deposits has been investigated by substantial amounts of core drilling and lesser amounts of RC drilling. In addition, limited open pit mining programs have been carried out on each deposit, with production processed in the Don Mario mill from 2009 to 2011 for both CF and LT. Results of drilling and pit mapping programs have shown that in both of these cases, gold is the predominant metal of interest and that the style of mineralization present closely resembles that seen within the LMZ. This further underlines the unique nature of the UMZ deposit and demonstrates that economically important mineralization characterizes both the Cristal Belt and the Eastern Schist Belt.

The current mining methods used at Don Mario UMZ are conventional open pit mining. Ore and waste are loaded into 20 to 25 tonne nominal capacity trucks using a 10 tonne nominal capacity front end loader. The ore is hauled directly to the process plant ore stockpile area and waste is hauled directly to the waste dump facility. Any oxide or low grade material is hauled to various surface stockpiles located near the plant and mine.

The Don Mario operation currently consists of the exploitation of the UMZ and the LMZ) units by open pit that produces a nominal 2,500 tonnes per day of ore of two material types – transitional and sulphides. Future mining of the remaining LMZ resource and Cerro Felix (CF) resources are expected to utilize open pit mining methods.

Mining of ore and waste occurs on 5m benches. The overall mining sequence was generated by Cube Consulting Ltd. (Cube) and was reported previously by Zandonai (2013). The sequence consists of 4 main phases or pushbacks. All the design parameters associated with the pit design were provided by EMIPA. Standard haul road design width for a double lane system is 10 m. This complies with that specified by EMIPA and it includes the drainage ditch and the safety berm.

The Don Mario mine is an operating open pit mine. Access to the existing workings areas is through one main ramp; located in Phase 3 providing good access to the plant to waste dumps and stockpiles. This ramp is used for transport of people, materials and equipment to the open pit workings as well as for hauling ore to the plant and stockpiles and waste. The final ramp located in Phase 2 is open for transportation and access to upper benches.

The current pit design assumes the mine is operated with small equipment (20-25 tonnes capacity) and all the design parameters have been provided by EMIPA. Standard haul-road design width for a double-lane system is 10 meters. This complies with that specified by EMIPA and it includes the drainage ditch and the safety berm.

The estimated overall pit slope angle for this configuration is equal to 32 degrees. The overall geometry of the pit is designed on 5-m benches with a batter angle of 65° and inter-ramp angles of 35°, berm width of 5 m and haul roads of 10 m. These assumptions should be confirmed by a geotechnical study regarding the rock properties of the Sulphide zone.

Don Mario processing plant consists of the following sequence of macro unit operations:
• Crushing and Screening
• Grinding and Cycloning
• Gravity Concentration
• Flotation Concentration
• Tailings Storage Facility (TSF).

Ore extracted from the UMZ pit is stockpiled and classified according to mineralogy, gold, copper, and/or deleterious element grades. When possible, a suitable ore blend is prepared to feed the mill. A front end loader collects the ore from the plant stockpile and delivers it to the crusher feed bin equipped with a 500 mm aperture slotted grizzly screen. The crusher feed bin has an apron feeder that feeds the primary single toggle jaw crusher and any apron feeder spillage is collected on a conveyor belt below. The jaw crusher set to 153 mm. The spillage and the crushed ore which is less than 90 mm in size are transferred to the next conveyor belt equipped with load cell type belt weightometer and this belt discharges into the 800 ton fine ore mill feed bin. A level indicator and controller in the mill feed bin controls the apron feeder feed rate to the jaw crusher to maintain the set level in the bin.

Dry crushed ore at P80 < 90 mm is fed to the SAG mill (5.5 m internal diameter by 2.7 m effective grinding length) by means of a conveyor belt equipped with a load cell type belt weightometer. The load signal controls the feed rate from the mill feed bin discharge conveyor onto the conveyor belt feeding the SAG mill. The pulp density in the mill is controlled by adding process water to the SAG mill inlet. Oversize material is removed from the mill discharge pulp with the discharge end trommel screen. The oversize fraction is delivered back to the SAG mill inlet, while the undersize fraction flows to the common pump box for both the SAG mill discharge and the ball mill discharge. The combined mill discharge is pumped to a cluster of three 380 mm diameter Krebs hydrocyclones for classification (there is one on standby). The cyclone overflow reports to the flotation section and the cyclone underflow is split, with part reporting to the gravity concentration section (approximately 100 tph) and the balance reporting to the ball mill feed. The ball mill has a 3.6 m internal diameter by 6 m effective grinding length. The cyclone overflow at 40% solids has a size of P80 < 106 µm.

Milling reduces the size of the ore to less than one mm and liberates metallic gold, copper and silver particles (in sizes between 100 µm to 500 µm) that are recovered by gravity concentration due to their density differences in comparison to the host rock. One product is obtained from this circuit:

The cyclone underflow that is split off to the gravity circuit passes over a vibrating screen with 1.5 mm metal panels. The screen oversize material returns to the ball mill discharge box. The screen undersize material is split between three Falcon SB750 (F-SB750) centrifugal concentrators. The F-SB750 concentrate is discharged to a concentrate tank, while part of the tails of the F-SB750 1 and 2 units feed two Falcon i350 (F-i350) units, respectively (working in series), the remaining tails flow returns to the ball mill discharge pump box.

The F-i350 concentrate is sent to a pre-concentrated gold tank which also receives the FSB750 concentrate. The final concentrate is pumped to the initial bagging station where it is filtered in the bag to reduce the moisture content to approximately 20%. The bagged gold concentrate is moved to a final “drying” area, where it is removed from the bags and allowed to dry out in an effort to reach a final moisture content of approximately 12% prior to repackaging in bags required for off-site delivery.

After grinding and gravity concentration, significant quantities of fine native gold and variable amounts of copper sulphide (mostly chalcopyrite) remain. The native metals and sulphides can be recovered in flotation.

Flotation process consists of a pre-flotation circuit, with a rougher stage, first and second cleaning, to remove contaminants, two copper rougher stages, two scavenger stages, two cleaner circuits and a final column cleaning stage. There are two additional columns to clean more copper concentrate if necessary.

The froths flotation of the pre-flotation circuit, go to tailings, while the non-float rougher stage goes to a conditioning tank where flotation reagents are added and the material is sampled. The slurry is conditioned by the addition of the following reagents:

1) Lime to modify pH, 2) Danafloat 245 promoter 3) Xantato Z-11 4) MIBC frothing agent

The conditioned slurry flows by gravity to the rougher cells for copper. The flotation tails are pumped to the tails thickener, while the rougher and scavenger concentrates are directed to two stages of cleaning and then a final column cleaning. The final concentrate moves to the concentrate thickener where it is sampled just before the thickener.

Cleaned copper concentrate flows to an eleven metre diameter concentrate thickener. The concentrate is sampled before being discharged to the thickener. The underflow from the thickener and clarifier is pumped to a transfer tank where the slurry is sampled and then to a pressure filter feed tank. The concentrate is then pumped from the pressure filter feed tanks to the recessed plate pressure filter. The filter feed is sampled. The filtered concentrate at approximately 10% moisture is discharged and drops to the floor or directly to bagging stations below the pressure filter. The copper concentrate is then loaded onto trucks and transported to the port warehouse in Arica where it is stored, sampled and loaded onto a ship for sale.

The CIL circuit was placed on care and maintenance in April 2011 when the Company commenced mining the metallurgically more complex UMZ.

The re-commissioning of the carbon-in-leach (CIL) circuit was completed in January 2017. March 2017 gold recoveries of 86% exceeded the targeted average gold recovery of 80%, up from an average gold recovery rate of 55% using the prior flotation process.