Taca Taca has porphyry copper-gold-molybdenum mineralisation located in the southern half of a 50 km long Ordovician batholith, which forms the Sierra de Taca Taca mountain range. The Taca Taca mineralisation is hosted by plutonic rocks of granitic composition together with lesser dacite, dolerite, and rhyolite intrusions. The porphyry is characterised by kilometre-scale zones of hydrothermally altered rocks that grade from a central potassic core to outer phyllic and argillic zones. Phyllic alteration is most pervasive across the deposit and is closely associated with mineralisation.

Mineralisation is comprised of supergene (chalcocite) and hypogene (chalcopyrite) zones. A sub-surface leached horizon of varying thickness overlies the supergene and hypogene mineralisation. Mineralisation is disseminated and in fractures, veinlets, and quartz vein stockworks.

The leached horizon is largely depleted of copper mineralisation except for a zone of chalcocite-rich ore perched within the leached material to the east of the deposit. In addition, a zone of supergene gold mineralisation, close to surface, is present above the thickest portion of leached material.

Hypogene copper sulphides are mostly chalcopyrite with lesser bornite, chalcocite, covellite, and digenite. The mineralisation is broadly zoned with a chalcopyrite-bornite-molybdenite core yielding to a stronger pyritic halo around the outer edges. Supergene zones are mostly secondary sulphides formed by enrichment within a discontinuous blanket underneath the leached cap.

Supergene mineralisation is often variably mixed with hypogene mineralisation and is often due to deep-seated alteration along structures and host rocks. Fine-grained black chalcocite and lesser covellite are the main secondary copper sulphides.

Mineralisation remains open at depth and around several peripheral areas of the deposit.

The Taca Taca deposit grades, geometry, and depth make it suitable for conventional, large-scale, bulk open pit mining methods involving blasthole drills, diesel hydraulic excavators, electric shovels and off-highway haul trucks.

Open pit mining would proceed in phases from an initial starter pit, supplying pre-strip development waste for site infrastructure and construction, and ore onto stockpile for process plant commissioning. The average and maximum material movements over this three year timeframe are 32.9 Mbcm and 43.3 Mbcm, respectively. There is a pronounced peak in material movements over the next ten years as the first three pit phases are completed and mining proceeds into the fourth phase. The average and maximum material movements over this period are 91.9 Mbcm and 95.7 Mbcm, respectively. Thereafter, the average and maximum material movements reduce to 42.3 Mbcm and 65.2 Mbcm, respectively.

Loading and hauling
A fleet of Company owned and operated primary mining equipment would be used for loading and hauling of plant feed to a ROM pad crusher at the processing plant , and for waste to external dumps, and ore to interim stockpiles. It is expected that on-highway trucks would be used to haul material to the TSF starter embankment as required.

The primary loading and hauling equipment is expected to be electric powered shovels with approximately 90 t bucket capacity, matched with 360 t capacity haul trucks. A large excavator (800 t mass) would supplement the shovel fleet in smaller working areas to maintain efficient production. Front end loaders would be used for clean-up and stockpile rehandle as required.

A diesel powered excavator (350 t mass) and small haul trucks (85 t capacity) would be used to perform pioneering work, develop haul ramps for the shovels and other development activities as required.

Depending on excavation conditions and horizons, bench heights and mining lateral dimensions may vary in different areas of the open pit.

Trolley-assisted haulage
An improved haulage efficiency measure can be adopted, where applicable, using trolley assisted trucks for ore and waste haulage.

In-pit ore crushing and conveying
Also subject to further work during the engineering phase, there is the possibility that in-pit crushing and conveying (IPCC) of ore could be adopted.

With the completion of the detailed ultimate and phased pit designs, detailed life of mine (LOM) production scheduling was completed using MineSched software. Scheduling assumptions included:
• minimum mining block size for phase 1,2,3 = 30 m x 30 m x 15 m (X, Y, Z); for phase 4 and ultimate pit = 45 m x 45 m x 15 m (X, Y, Z);
• mining flitch height = 15 m;
• sinking rate generally a maximum of six benches (90 m) per year, with minor increases when mining small areas (e.g. at the top of the deposit).

Features of the mining and production schedule are as follows:
• Mining commences in Year -3 starting with the pre-strip period, whilst processing commences in Year 1. The Project life (processing years) is 32 years.
• 240.1 Mt of waste is mined in the three year pre-strip period, during which time 17.4 Mt of ore is mined onto a stockpile for subsequent active and longer-term reclaim.
• The total material mined over the life of operations amounts to 4,543.0 Mt (1,737.0 Mbcm) of which:
- 1,758.5 Mt is ore with average grades of 0.44% Cu, 0.012% Mo and 0.09g/t Au, and
- 2,784.5 Mt is waste.
• The overall life of mine strip ratio (waste tonnes: ore tonnes) is 1.6 : 1.
• The direct feed ore to the plant is 1,390.4 Mt at an average grade of 0.50% Cu, whilst 57.1 Mt at an average grade of 0.43% Cu is ore reclaimed from active stockpiles, and 311.0 Mt at an average grade of 0.15% Cu is ore (marginal ore) reclaimed from longer term stockpiles (mostly in Years 27 to 32).
• The total ore mined includes 39.0 Mt of ore grading 0.46% Cu from the near-surface “leached cap”, of which over 15 Mt is mined to stockpile during the pre-strip years. Most of this ore is then processed over the following three years.
• There is a small area in the north west of the ultimate pit design that crosses over into a joint venture concession. The encroachment occurs between Years 5 and 15 and involves 1.7 Mt of ore and 47.5 Mt of waste.
• The Inferred Mineral Resource that is mined as waste amounts to 69 Mt at an average grade of 0.31% Cu (i.e., about 2.5% of the total waste mined). This material is encountered in the mining schedule after Year 6, and following completion of mining phases 1 and 2.
• The crusher feed ramps up from Year 1 at 30 Mt, to 40 Mt in Year 2, at which level it remains until Year 6. The feed rate then rises to 50 Mt in Year 7, and thereafter to 60 Mtpa until Year 32.
• In terms of total plant feed (after mining dilution/recovery):
- the average copper grade is 0.72% Cu for the first six years when processing at up to 40 Mtpa;
- then 0.45% Cu to Year 27 when processing at up to 60 Mtpa;
- and finally 0.15% Cu for the remaining five years of Project life when reclaiming from longer term stockpiles.
• Before the final five years of marginal ore reclaim, the total plant feed is 1,476.3 Mt at an average grade of 0.50% Cu.

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The Taca Taca processing feed would be both supergene (plus mixed) and hypogene (sulphide) primary ores. Primary ores are defined as those containing more than 50% of the copper present as chalcopyrite. Consequently, when treating primary ores, significant amounts of secondary sulphides will be present in the feed, and there may also be some tarnished minerals.

The preferred process route follows that of conventional porphyry copper-molybdenum concentrators common throughout South America, but including a sulphidising flotation circuit, using sodium hydrosulphide (NaHS) for sulphidising oxide and tarnished minerals. When treating primary ores with low acid soluble copper, the same circuit will be used, but the NaHS addition would be switched off.

A gold recovery circuit would not be constructed to treat the auriferous oxide cap during the pre-strip phase of mine development. However, this material would be stockpiled separately from waste material and subject to ........