The mineralization of copper is found in the form of oxides species (Atacamite, Malachite, Chrysocolla, etc.) and to a lesser extent, sulphides (Chalcocite). The Franke - Altamira “manto-type” copper deposit presents a Cu-Ag association. The flow breccias are of sub-aerial origin and they are found in most of the deeper drilling under the Franke deposit.

The uppermost unit of the Aeropuerto Formation is dominantly equigranular andesite, in contrast with the porphyritic flows of the middle portion and has little exposure on the surface of the district.

The middle portion of the Aeropuerto Formation that hosts most of the copper mineralization in the Altamira district is about 100 – 200 m thick at the Franke deposit and is dominated by distinctively discontinuous lava flows of porphyritic phases interbedded, in the upper part, with sedimentary rocks that are highly lenticular, indicating a fluvial or lacustrine terrestrial origin.

Most of the copper mineralization is hosted in porphyritic amygdaloidal andesites and ocoitas, but an important amount is hosted in equigranular andesites and in a lesser amount in volcaniclastic and calcareous sediments. Basal andesitic flow breccias and upper chocolate – brown andesites are generally barren units.

The high grade portion of the Franke deposit is formed by a large number of stratabound pods of different sizes, each one connected to one or more faults striking NW, WNW or N. These faults are now sealed by hydrothermal material and were used by the hydrothermal fluids to pervade into the favourable horizons (i.e. vesicular flows, contacts, micro fractures and stockworks). The horizontal size of these pods varies from a few metres to tens of metres from the feeders and the fading of the mineralization pinches within a very short distance, even if the favourable horizon persists.

The oxidation profile at Franke is rather complex, lacking clear definitive surfaces defining the top of the sulphides and the bottom of the oxides. The upper 20 m of the stratabound mineralization is largely, but not completely oxidized. Between 20 and 60 m depth, the mixed ores with subordinated sulphides are the most common assemblages while at deeper levels the sulphides start to predominate. Inversions of this sequence are very common and oxidized horizons may reappear under sulphide ore zones.

The selected mining method will be open pit mining, where haul trucks will be used to deliver mineralized material to a primary crusher for crushing and placement onto heap leach pads. The crusher is located west of the final pit, while the single waste disposal area is planned to be north of the final pit. It is scheduled to be completed in three horizontal platforms, with heights between 30 and 35 metres.

The haul road width of 16 m is approximately four times the width of these haul trucks which allows for two-way traffic and a safety berm on the outside edge of the road.

The run-of-mine ore will be fed through the open circuit crushing circuit which has a final product size P80 of ½ inch. The final crushing product is fed to two agglomerators at a total feed rate of 580 t/h. The agglomerators discharge onto the feed conveyor for the heap stacking system, which will build the 12 leach heaps of 300 x 86 x 4.25 m, which constitute the on/off leaching area. Depending on the leaching characteristics of the block of ore, it will be irrigated with leach solution for between 60 and 180 days. Sufficient pad area has been provided to accommodate the required copper production with the anticipated leach cycle requirements. The agglomerated ore will be leached to a life-of-mine average recovery of 86.9% with a specific net acid consumption of 11.6 kilograms of acid per kilogram of copper cathode produced.

In the leaching area there are solution ponds for Pregnant Leach Solutions (PLS), Intermediate Leach Solutions (ILS), and raffinate. The PLS will be collected in a 17,000 m 3 pond, then transported by gravity to the solvent extraction plant, while the leached residues will be transported to the mine waste dump by truck.

The solvent extraction electro-winning plant will be a proprietary design supplied by Outotec. The pregnant leach solution will be fed to the series-parallel solvent extraction circuit where the copper will be transferred to an organic extraction reagent. After washing the organic to remove impurities, it will be sent to the stripping stage where the rich electrolyte, with an average copper concentration of 50 g/L, will be generated and sent to the electrowinning tankhouse. Here, high purity copper metal cathodes will be produced by electrolysis.