The Touro deposit is hosted in a continuous, highly deformed and metamorphosed horizon of metabasite and paragneiss of the Arinteiro Unit (Ordenes Complex). This horizon outcrops along the flanks and hinge zone of a broad north plunging antiformal structure for at least 8km along strike and up to 2km across strike. It extends beyond the project area and is open to depth.

The Arinteiro Unit is composed mainly by metabasites with minor lenses of ultramafic rocks and paragneisses (Gomez Barreiro, 2007). The mineralogy, grain size, and homogeneity of the metabasites are variable, most of the rock types are hornblende-plagioclase rocks with or without garnet (almandine), clinopyroxene (salite), and quartz. The rocks have undergone varying degrees of cataclasis commonly associated with retrogressive greenschist facies assemblages. The metabasites are strongly deformed showing tectonic banding, intrafoliar folds and oriented nematoblastic texture. Very locally, relict igneous textures have been described supporting the theory of a gabbroic protolith (Castineiras et al., 2002; Gomez Barreiro, 2007).

The metasediments of the O Pino Unit lie above and below the metabasites that have been interpreted as representing a flysh sequence (Gomez Barreiro, 2007). This unit is composed mainly of paragneisses with predominant greywacke composition. Minor pelitic metasediments, biotitic shists (sometimes rich in graphite), and amphibolite gneisses are also described in this unit.

According to Atalaya Mining, there is a main horizon of paragneiss in the project area with an estimated thickness of around 400m that hosts metabasites that are represented mainly by amphibolites interbedded within the metasediments. The metabasites appear to represent a single level event of volcanic or subvolcanic origin. The thickness of the amphibolite horizon based on the drilling data of Atalaya Mining, varies from a few meters to up to 90 m.

Rock weathering is limited to a few meters below the surface.

Mineralization.
The ore zone consists of one or two mineralized horizons of disseminated mineralization closely associated with coarse grained garnet amphibolite that is poor in calcium. Garnet content is up the 90% of the volume of the rock (garnetite). The garnet amphibolite grades into non-mineralized normal amphibolite with decreasing garnet content.

The whole amphibolite horizon is surrounded by metasediments, mainly paragneisses that are normally barren or weakly mineralized although mineralized paragneiss has been described in Arca and Monte das Minas in the lower paragneiss.

In general, the ore bodies are tabular, shallow dipping, very consistent and continuous in terms of geometry but with variable thickness. The mineralization hosting amphibolitic metabasites are composed by gedrite, almandine and minor staurolite, and albite-oligoclase.

The mineralization is represented in order of abundance by pyrrhotite, chalcopyrite and minor pyrite and sphalerite. Williams (1983) described evidences of pre- and syn-deformation in garnets and sulphides (pyrrhotite and chalcopyrite).

The sulphides in the amphibolite are mainly disseminated and aligned with foliation planes, are either interstitial to amphibole crystals, infill the cracks of garnet porphyroblasts together with quartz, concentrated in pressure/strain shadows, or form veinlets parallel to the rock schistosity, with quartz, chlorite, and carbonates.

The semi-massive sulphide horizon is represented by rounded fragments of the host rocks within a pyrrhotite matrix with lesser amounts of chalcopyrite and minor pyrite and sphalerite. Massive sulphide orebodies in shear zones are also described in Fornas and Manoca, further west of Touro. The zinc contents increase significantly in this type of mineralization compared with the disseminated ore type.

Seven open pits will be developed around the arc of mineralization at Touro: Arca, Arinteiro-Vieiro, Bama, Brandelos, and three separate pits in the Monte de las Minas area.

The mineralization at Arinteiro is hosted in a single ore zone of garnet amphibolite of roughly N-S to N20E orientation and dipping around 25° to the East. The mineralized garnet amphibolite is flanked by paragneiss in both hanging wall and footwall.

Average thickness of the ore zone ranges from 20 meters up to a maximum of 56 meters (mineralized intersection in drill hole IAR11) and it appears to end at depth towards the east. Average grade is 0.62% Cu. Sulfide mineral assemblage is represented by pyrrhotite, chalcopyrite and minor pyrite (Figure 7.6).

The Arinterio deposit is aligned with and extends to the Vieiro deposit to the north along a N170 trend.

Vieiro is located immediately north of Arinteiro deposit. The mineralization is also hosted in garnet amphibolite that occurs as interdigitated lenses within the paragneisses (Figure 7.7), therefore making the geometry of the orebody more complex than Arinteiro. This complexity is responsible for significant variations in thickness of the ore zone. The general dip of the ore zone is 25° to the east, but on the northern side of the deposit the structure plunges around 15° to the north.

Maximum ore zone thickness intercepted by Atalaya Mining drilling is 56 meters at 0.60% Cu with the best grade intersection of 16 meters at 1.46% Cu.

Bama is located on the hinge zone and western limb of the anticline. Mineralization is also hosted in garnet-rich amphibolite and flanked by paragneisses. It consists of disseminated pyrrhotite and chalcopyrite. Thickness of the mineralized ore zone varies from 15 meters up to 60 meters.

In Atalaya's opinion, the main Bama ore zone has a "graben-like" geometry that is thought to be associated to synsedimentary faults. The shape of the orebody is gently adapted from the margin of the deposit to the center, where the orebody has a greater thickness.

Brandelos is located in the western limb of the anticline and dips gently to the west about 10° to 20°. The ore zone is hosted in garnet amphibolite and flanked above and below by paragneisses. The ore zone forms a tabular lens with thickness varying between 15 to 50 meters and average grade of 0.40% Cu. Brandelos is the western extension of the Bama ore zone and remains open to depth down-dip to the west.

Area is located in the west-central part of the Project area and connects with Monte das Minas to the north.

Drilling has identified the occurrence of several mineralized lenses, of which the biggest one is located on the western part of Arca. The ore zones are sub-horizontal in the central area, and dip 20°-30° to west in the western side. Most of the lenses are garnet amphibolite with thickness varying from 10 meters up to 100 meters with an average grade of 0.42% Cu (Figure 7.8). The thickest drill hole intersection of Atalaya Mining drilling is 112 meters at 0.46% Cu. The lower mineralized horizon is represented by breccia textured semi-massive sulphides hosted in paragneiss.

Monte das Minas is located in the northern zone of the project area, mostly in the hinge zone of the antiform, this deposit is the extension of the Arca ore zone.

The deposit consists of up to 5 lenses of disseminated sulfides, the upper ones hosted in garnet amphibolite and the lower one in paragneiss (Figure 7.9). The lenses are sub-horizontal and occur at shallow depths, ranging in width between 10 meters and 60 meters. Average grade is 0.45% Cu, although there are some high-grade zones with up to 1% Cu.

Open pit copper mining operations have been conducted within the Touro project site during the 1970s and 1980s before being shut down in 1986 due to low metal prices. Old pit walls are presently standing well and vehicular access exists into the pit areas. Some pit dewatering will be required prior to new development work, particularly in the Vieiro pit.

Redevelopment of copper mining operations will use conventional, open pit methods, mining from benches on 10-m vertical intervals. Contractors' small-to medium-scale mining equipment will be used, including: rock drills capable of drilling 102- to 127-mm-diameter blastholes, hydraulic excavators and/or front-end loaders with bucket capacities of approximately 6-13 m3, off-highway trucks with 55- to 91-t payload capacities, and suitably sized support equipment.

Mining Pits/Phases.
Seven pits were developed using Lerchs-Grossmann (LG) pit shells based on a copper price of $2.60/lb, the final pushbacks for which are: Arinteiro-Vieiro, Arca 2, Bama 2, Brandelos 2, Monte 3, Monte 4, and Monte 5. Arinteiro-Vieiro has high Cu grades along with a high stripping ratio, and is the primary development target in the early years of operation. Five initial phases were designed to improve mill head grades during the first 6-7 years of operation, targeting smaller pit extents identified by $1.75 and $2.00/lb Cu LG shells. These phases are identified as: Arca 1, Bama 1, Brandelos 1, Monte 1, and Monte 2. "Monte" refers to the Monte de las Minas deposit area.

Pit bottom sinking rates were limited to about four benches per year. Typically, mining activity would occur in 4-5 phases during each year to smooth fluctuations in head grade and stripping rates. Two to three phases would be active at any given time.

Mine Production Schedule Summary.
Preproduction stripping, totaling about 35.7 Mt, would commence about 18-24 months prior to mill startup depending on the details of sequencing waste rock placement in the initial tailings dam. Only the Arinteiro-Vieiro would be active during this period.

Peak stripping rates would extend through the latter part of year 3. Mining from the Arinteiro-Vieiro pit comprises just over 90% of the total material movement through the end of Year 3 and 85% through the end of year 5. Over 3.0 Mt of low grade ore would be stockpiled from preproduction stripping through Year 5. Total daily material movement during Years 1-3 would average nearly 97,000 t, assuming a mine operating schedule of 360 days per year.

Stripping rates fall off during years 4-6, but would increase afterwards to open up Arca 2, Bama 2, and the remaining Monte phases. Ore mining and processing rates would increase after Year 5 to compensate for lower head grades. Arinteiro-Vieiro would be mined out in the third quarter of Year 6. Stockpiled low grade ore would be fed to the plant in Years 11 and 12 to augment ore production from the remaining mining phases - primarily Arca 2, Monte 4, and Monte 5. Total daily material movement during Years 711 would range between 62,000 and 71,000 t/d (at 360 operating days per year).

The proposed process flowsheet uses a conventional SAG mill - ball mill (SAB) grinding circuit followed by a copper flotation recovery circuit. The initial concentrator includes:

• Primary crushing.
• Primary and secondary grinding.
• Rougher flotation.
• Regrinding.
• Three stages of cleaner flotation.
• Concentrate thickening and filtration.

The concentrator and associated service facilities will process run-of-mine (ROM) ore as delivered to the ROM pad to produce a dewatered copper concentrate and tailings slurry. The preliminary mining schedule is outlined as follows:
• In the first year of operation, annual ore movement to the plant ramps up to 5.1 million tonnes.
• In the following two years of operation, the peak annual ore movement to the plant is 6.0 million tonnes.
• From year 8 on, the annual ore movement to the plant ramps up again to 10.0 million tonnes.
• Over the life of mine, the peak annual ore movement to the plant is 10 million tonnes.

To avoid three successive plant upgrades, a simplified approach has been taken with only two design points and upgrades considered for the process plant:

• Initial Phase 1 plant throughput of 6.0 Mt/y.
• Phase 2 upgrade to increase plant throughput of 10 Mt/y prior to year 8.

The Phase 1 average head grade is 0.53% Cu with a peak of 0.57% Cu. The Phase 2 average head grade is 0.35% Cu with a peak of 0.38% Cu. The overall result is consistent concentrate and copper production for both phases. A simplified process flow diagram (Figure 17.10 shows the 6.0 Mt/y Phase 1 in black and the 10 Mt/y Phase 2 additions in blue).

Primary Crushing.
ROM ore is transported from the open pits to the primary crusher by mine haul trucks, which dump directly into a 200 t ROM bin positioned above the primary crusher, from either of two dump points. The bin has sufficient capacity for two truckloads. The ROM bin is equipped with a fixed rock breaker to reduce oversize material and remove potential blockages.

The ore is crushed by a 42 inch primary gyratory crusher with a 375 kW motor. Crushed product with a nominal P80 of 128 mm is removed from the crusher discharge chamber via a 1,350 mm wide belt feeder. Crushed ore transfers to the 1,200 mm wide crushed ore stockpile feed conveyor onto the crushed ore stockpile.

The crushed ore stockpile provides 18,313 t of live storage with two reclaim apron feeders located in a tunnel under the stockpile. Each feeder is capable of providing the nominal SAG mill feed rate of 1,250 t/h that is required for the 10 Mt/y throughput case.

Grinding Circuit 6.0 Mt/y.
Coarse ore reclaimed from the crushed ore stockpile is conveyed to the SAG mill feed chute by the 1,200 mm wide SAG mill feed conveyor at a nominal rate of 750 t/h. Dilution water is added to the SAG mill at the feed chute such that the mill discharge solids concentration is a nominal 72% w/w. Lime is added to the SAG mill feed chute.

SAG Mill.
The nominal SAG mill dimensions are 10.36 m diameter and effective grinding length (EGL) of 6.64 m. The SAG mill is trunnion mounted and is powered by twin pinions with each pinion driven by a 7.25 MW motor through a gearbox for a total mill power of 14.5 MW. Each motor is a hyper-synchronous SER drive which allows operation between 60 and 80% of the mill critical speed. The nominal mill speed is 75% of critical speed.

The SAG mill is fitted with steel liners and uses 125 mm forged steel grinding media. The grinding media is added to the SAG mill feed conveyor via a ball charger. The SAG mill discharge is equipped with a trommel screen with 12 mm apertures.

Ball Mill.
Ground ore passes through the SAG mill discharge trommel to the mill discharge hopper. Slurry from the hopper is pumped by duty/standby slurry pumps to a cluster of eight 660 mm diameter cyclones. The cyclone cluster classifies the slurry to give an overflow of P80 of 125 µm at a density of 37% w/w solids. The cyclone underflow is discharged at nominally 75% w/w solids and flows by gravity to the ball mill feed chute, with up to 25% of the underflow able to be directed to the SAG mill.

The ball mill is rubber lined and uses 60 mm steel grinding media. Each mill is fitted with a trommel screen with 8 mm slots to facilitate scats removal.

Grinding Circuit 10 Mt/y.
The SAG mill discharge grates are modified to include pebble ports to facilitate pebble extraction at approximately 25% of new feed rate. Two 5/4 foot 200 kW Symons cone crushers are installed to reduce the pebble size to a P80 of nominally 12 mm. The sizing of the crushers is such that one runs constantly choke fed, while the other is choke fed intermittently to control the surge bin level between high and low levels.

A second identical ball mill and four additional 660 mm cyclones (installed in the existing cyclone cluster) are installed for the 10 Mt/y throughput. Cyclone underflow is split equally between the two ball mills using the Phase 1 SAG mill cyclone underflow distribution box.

Flotation Circuit 6.0 Mt/y.
Rougher Flotation.
Ball mill cyclone overflow flows by gravity to the first of six 130 m3 rougher tank cells. Collectors (PAX and thionocarbamate) and frother are added to the first cell. Copper concentrate is collected from each cell and laundered to a common concentrate hopper and pumped via the duty/standby rougher flotation concentrate pumps to the regrind mill discharge hopper. The tailings from the rougher cells discharge into the tailings hopper from where they are pumped to the Tailings Storage Facility (TSF) by duty/standby pumps.

All flotation cells are equipped with agitators and forced air dispersion systems.

Regrind Circuit.
Rougher flotation concentrate reports to the regrind mill discharge hopper and is classified in a cluster of eight 250 mm diameter cyclones. Cyclone overflow at nominal Pso of 20 ^m and solids concentration of 20% w/w solids flows to the cleaner conditioning tank. The cyclone underflow at nominal 65% w/w solids flows by gravity to the Regrind ball mill feed chute.

The regrind ball mill dimensions are 4.2 m inside shell diameter and EGL of 7.4 m. The mill is trunnion mounted and powered by a single pinion drive with a 2 MW motor through a gearbox. The motor is fixed speed at 75% of the mill critical speed, and started by a liquid resistance starter (LRS). The ball mill is rubber lined and uses 25 mm high chrome steel grinding media. The mill is fitted with a trommel screen with 1 mm aperture to facilitate scats removal.

Cleaner Flotation.
The cleaner flotation circuit consists of three stages of closed circuit cleaning, with cleaner scavenging on the first stage cleaner tailings.

Flotation Circuit 10 Mt/y.
The rougher circuit is increased by three additional 130 m3 primary rougher cells installed ahead of the existing rougher cells. The concentrate from these cells is laundered to the primary rougher concentrate hopper and pumped by a duty/standby pump pair to the new primary cleaner flotation column feed box. Tailings from the new primary rougher cells will flow by gravity to the first of the existing rougher cells.

The new primary cleaner flotation columns clean the primary rougher concentrate to produce the final concentrate grade. Collectors (PAX and thionocarbamate) and frother are added to the column feed box.

The primary cleaner concentrate and combined final concentrate (primary cleaner and cleaner 3 concentrates) are added to the OSA system to give a total of 12 streams being measured.

Filtered concentrate is discharged into a concrete bunker from where it is transferred by FEL to the 3 000 tonne capacity concentrate storage shed.