The Cerro Maricunga deposit type being explored for is a porphyry gold deposit developed in, and associated with, Miocene domal intrusives. These characteristics can include mineralization/alteration types which appear to be intimately associated with, or occur below, high level, high sulfidation epithermal mineralizing systems developed in variably eroded and collapsed Oligocene-Upper Miocene stratovolcanoes and within recurrent intrusive dacitic domes. Hydrothermal and phreatic breccias are frequently developed flanking and transecting (and below the steam heated zones) the domal intrusives and most commonly at fault intersections and/or zones of dilation.

Microscopy studies indicate that gold mineralization at Cerro Maricunga primarily occurs within black and grey banded veinlets (BBV and GBV) in porphyry and breccia, and secondarily within early chloritemagnetite-quartz veinlets.

Gold mineralization may be encountered in phreatomagmatic breccia, surrounding hydrothermal breccia, in dacite porphyry and also surrounding andesitic dikes and plugs.

Mineralogical data presented herein was prepared by AMTEL.

Gold deportment studies were carried out in three composites of the Phoenix zone with results indicating that gold occurs in two forms: native gold and submicroscopic gold in FeOx.

Native gold is observed as free particles; attached to FeOx, to rock or both; and enclosed (in rock and/or FeOx).

Free particles of gold within the composites are very small with 75-95% smaller than 10 µm. Gold composition is of high purity (on average >99% Au).

Submicroscopic gold (noted as “refractory”) is carried mainly by goethite followed by hematite (referred collectively as FeOx).

The Mineral Reserve is that part of the Mineral Resource which can be economically mined by open pit mining methods.

Slope angles used for pit optimisation were a result from an analysis performed on the pit design developed for the PEA study. Several measurements were made in different directions, getting values between 40° and 41° for the overall angles, taking into account ramps and geotechnical catch berms.

The total area of the pit was divided into three zones: North, Central and South, assigning overall angles for pit optimisation of 40°, 41° and 40°, respectively.

The road width of 38 m will accommodate the selected 290 t trucks. NCL used a 10% road gradient which is common in the industry for this type of trucks. The current mine plan is designed with 10 m benches stacked to 20 m (i.e. double benching). Mining costs for this report are based on blasting 10 m benches for the waste zones and for the ore.

Run of mine ore will be crushed in a primary, secondary and tertiary crushing circuit and then treated by a heap cyanidation process, in order to recover gold.

The processing plant has been designed for an annual working rate of 360 days for the crushing plant, and 365 days for the leaching and ADR plant, therefore the crushing plant considers a nominal throughput of 81,150 tpd, while the leaching and ADR plant 80,000 tpd. The average head grade considered for plant design is of 0.5 g/t of Au and 0.25 g/t of Ag. The resources available for the project are estimated to be 294 Mt, establishing the project life at 13 years.

Run of mine (ROM) material is transported by trucks to the primary crushing facility at a rate of 81,150 tpd, where it is discharged directly into the dump pocket of the primary gyratory crusher, operating with an open side setting of 165 mm (6’’) to achieve a product size P80 of 116 mm.

Primary crusher discharge is then transported by an overland conveyor system to a coarse material stockpile with a live capacity of 34,500 t, equivalent to 10 hours of operation.

Material from the coarse stockpile is conveyed to the secondary and tertiary crushing stage. The material is firstly classified with two conventional screens of 10 ft x 24 ft each and slot opening of 38 mm. The undersize material is conveyed directly to the fine stockpile, while the oversize material is fed to two cone crushers operating with a closed side setting (“CSS”) of 35 mm. The product of the secondary crushing stage has a P80 of 44 mm.

Crushed material is conveyed from the fine stockpile to the leaching heap initially by a tripper conveyor located at one side of the heap and then loaded onto the heap using a grasshopper and radial stacker system.

Gold and silver are recovered through the use of a weak cyanide solution which irrigates the stacked material using drippers over a 160 day cycle. In this cycle the material is irrigated in two stages to maximize initial gold value in the pregnant solution. Fresh material is leached with intermediate leach solution (ILS) which contains a medium gold tenor, and pregnant leach solution (PLS) is obtained, which is sent directly to the ADR plant. The material that has been irrigated for more than half the cycle (80 days) is then leached with barren solution to obtain an ILS. The ILS solution irrigates and drains through the leach heap, reports to the PLS pond and from there is pumped to the ADR plant where gold is adsorbed onto activated carbon. Gold stripped solution exiting the ADR plant is pumped to the barren solution pond. This circuit minimizes solution flow volumes downstream of the heap leach and also increases gold tenor in solution reporting to the ADR plant.

The irrigation system designed will evenly apply cyanide solution directly on the heap leach surface, to ensure leaching throughout the heap. For design purposes, an irrigation rate of 10 l/hr/m2 and 160 days irrigation cycle, 80 days with barren solution and 80 with intermediate solution, were considered.

The process to recover gold and silver from PLS, ADR plant, involves three stages: adsorption, desorption and regeneration.

In the adsorption stage, gold and silver contained in the PLS solution are loaded onto activated carbon. The process considers three trains operating in parallel with five adsorption tanks each, where the pregnant solution passes in counter current by the activated carbon.

The carbon is loaded into the elution column by a carbon transfer pump from the first stage of the adsorption circuit. The carbon falls directly into the column and unnecessary moisture is allowed to drain to the floor, where it will be picked up by a vertical spindle spillage pump and discharged to the overflow launder at the last adsorption tank.

Loaded carbon is then pumped into the elution columns, were a modified Anglo American Research Laboratories (AARL) process is carried out. The carbon is pre-soaked with a caustic cyanide solution and eluted with cold water for copper removal, then acid washed to remove the contaminants in the carbon, and then water washed and pretreated with a caustic/cyanide solution, to be then eluted for gold and silver using hot water al 110° C.

Eluted carbon is hydraulically transferred from the elution column, dewatered and regenerated at 600-700° C every four cycles. A horizontal regeneration kiln is installed to regenerate the carbon after elution. Regenerated carbon passes through a carbon sizing circuit to remove fine carbon before returning it to the adsorption trains.

Pregnant solution produced from elution process is stored in the electrolyte tank and circulated through electrowinning cells, where gold and silver are transferred onto cathodes. Facilities are designed to recirculate electrolyte back to the electrolyte tank and through the cells until solution tenor drops below a desired level of gold concentration, considering it spent solution. Spent electrolyte solution is then pumped to the barren pond, to be reused in heap leach.

Gold loaded cathodes are removed from the cells, calcined and smelted into doré bars, which are the final products of the process, and stored in a vault from their commercialization.