The property contains a mill that is permitted to operate at 3,000 t/d, fed by various sources near the property including: the Cinabrio mine; Dalamacia open pit mine (in development); the Dalmacia underground mine (in development); the Los Mantos open pit mine; and the Milagros underground mine.

Cinabrio
Cinabrio is an Iron Oxide Copper Gold (IOCG) type manto deposit. Mineralisation has a strike length of approximately 750m and the mineralisation is between 10 and 30 metres thick and is very continuous up to a depth of around 700 metres. The mineralisation of predominantly chalcoyprite and minor bornite and pyrite dips steeply to the east and occasionally faulted. Immediately to the south west is the San Andres property which is the faulted offset of the top of the Cinabrio orebody. San Andres is approximately 10 to 15 metres in thickness and additional exploration is required to define its depth limits.

Dalmacia
Based on existing information Dalmacia is located within a roof pendant of volcanic rocks with minor calcareous intercalations of the Agua Salada Complex. This volcano sedimentary complex is intruded by granites of the Illapel Batholith (105-130 Ma) located in a reverse fault.

Milagros and Los Mantos
The geology at Milagros and Los Mantos here contains thin layers of limestone, which appear to be lenticular. Where exposed the limestone layers are mostly about 2 meters thick, but in a few places they bulge out to a much greater thickness. They strike nearly north, and their dips range from 45° W. in the central part of the area, south of the Los Mantos mine, to approximately 90° in the northern part. The limestone has been metamorphosed in widely varying degree, some of it being only a little bleached, whereas some has been altered to a massive garnet rock. Lamprophyre dikes, only 1 or 2 meters thick, are continuous within the Los Mantos vein underground as well as in the granodiorite at the surface. Those seen underground all dip steeply west, but in the granodiorite at the surface some are flat lying and others are vertical. The principal intrusive rock is a typical biotite-hornblende granodiorite containing many dark inclusions. It contains a moderate quantity of quartz, rather abundant hornblende and biotite the latter partly altered to chlorite and epidote along cleavages and accessory sphene, magnetite, and apatite.

The outstanding structural feature of the district is a zone of faulting and minor shearing that was traced intermittently from the northern to the southern end of the área (1km distance and up to 50m wide and 450m depth) It is marked by pockets and streaks of a peculiar, fine-grained fault breccia, consisting of ground-up fragments of volcanic and sedimentary rocks, granodiorite, and of vein material.

The mineralisation can be considered as a vein shear system with copper as chalcopyrite and chalcocite, gold, silver and mercury as cinnabar and mercurian tetrahedrite.

In general mineralization occurs as impregnations and/or disseminations in all strata, affected by preexisting fractures and minor faults. The economic mineralization is controlled by feeders and includes chalcopyrite, bornite and the gangue includes pyrite, calcite and quartz. In the oxide and transition zones (nominally 40 to 60 metres depth but quite variable) malachite, azurite and chrysocolla and native copper are common. It is emphasized that the dominant mineralogy in the enrichment zones consists mainly of chalcocite, bornite and chalcopyrite. In greater depth, mineralization is estimated to contain primary sulphides (pyrite, chalcopyrite and bornite).

The property contains a mill that is permitted to operate at 3,000 t/d, fed by various sources near the property including: the Cinabrio mine; Dalamacia open pit mine (in development); the Dalmacia underground mine (in development); the Los Mantos open pit mine; and the Milagros underground mine.

All mining is performed by a contractor.

In some cases, larger units may be appropriate. For example, larger 8 yd³ scooptrams rather than the existing 6 yd³.

As the Cinabrio deposit deepens, the first real test for the equipment will be the haulage time from the bottom of the mine. This may prompt the evaluation of larger haulage trucks; the width of the ramp, at approximately 5.5 m, should be able to accommodate trucks as large as 50 t and still provide 2.0 m free space.

However, as all of the equipment is contractor-owned, such efficiencies are only relevant if the contract is structured to provide a lower cost to Minera Altos de Punitaqui (MAP).

Each mine has its own bolting standards which are based on the Bieniawski Rock Mass Rating (RMR), a typical industry standard. The RMR varies from 40 to 80, which corresponds to “poor” to “very good” ratings.

Splitsets are used throughout the mines in lengths of 1.8 m, 2.4 m and 3.0 m with mesh. A 1 to 2-inch layer of shotcrete is applied to fault zones.

Many of the headings underground are not bolted. In these zones the back was typically completely covered with half-barrels of the drillholes, a reliable indication of good ground conditions. The possibility of wedges should still be considered.

The Dalmacia open pit mine is designed for 6.9 m wide x 12 m high benches with face angles of 70° and an overall slope angle of 49°, as shown in Figure 24-1.

Waste dumps are designed for 9.6 m wide x 8 m high benches and assume repose angles of between 36° and 39°, resulting in overall slope angles of 23°.

Cinabrio Underground Mine
Operating since 2011, the Cinabrio Mine has been the largest producer at MAP. In 2017 it had produced at a rate of approximately 1,300 Mt/d, representing 44% of the mill feed for the year.

The orebody dips at approximately 50° with thicknesses of between 20 m and 100 m extending from the top at 1,000 mASL to the current bottom at about 400 mASL.

Most of the mining levels are unbolted and the ground is solid and competent, with the exception of some fault zones, which are supported with splitsets and shotcrete.

Sublevel open stoping is employed with a 30 m vertical distance between levels. The stopes are mined using uphole drilling. A slot is developed from hangingwall to footwall across the width of the stope then parallel rings are blasted into the open void. All stopes are non-entry to personnel. Remote scooptrams are employed regularly for complete extraction. Haulage from the mine is accomplished using 30 t diesel haulage trucks.

Mining is completed without cemented, self-supporting backfill, and massive pillars are left for support that are continuous from hangingwall to footwall. All development waste is placed in completed stopes, offering confining support to the hangingwall through most, though not all, of the mined areas.

Dalmacia Underground Mine
The Dalmacia deposit is modeled as numerous discrete and discontinuous pods of mineralization.

The Dalmacia underground mine has one level completely developed at 315 mASL. It is currently laid out for sublevel open stoping using a 20 m sublevel spacing without backfill in a similar fashion to the Cinabrio mine.

Plans exist both for underground mining and surface mining of the deposit. As the topography is fairly hilly, an open pit plan would only recover the upper portion of the orebody and, if viable, continued extraction would be done using underground methods.

Dalmacia Surface Mine
As stated, plans exist for a “super pit” for the main Dalmacia deposit, which is currently developed on one level as an underground mine. However, there is a second discrete zone to the East of the underground mine, which is also called the Dalmacia open pit mine, but has the historical names Nova Galicia and Arco Iris.

The mine is currently operating under an exploration permit that allows for 3,000 Mt/d of total mining. The mine in the process of applying for a full mining permit that would allow 20,000 Mt/d. It is being excavated with 12 m high benches.

The strip ratio is currently estimated to be 3:1. More drilling is required to determine the extent of the numerous planned pits and which will merge into much larger pits. The pit will start with a heavier-thanaverage ratio of CuS to CuI.

Three waste dumps are planned for the pit, all within 1.5 km haulage distance.

Milagros Underground Mine
The Milagros mine is a historic gold mine in which the high grade core has been mined out, but the low grade fringe which housed the core remains, as demonstrated in Figure 24-10. The mined-out high grade core is represented in yellow and generally averages 3 m thickness. The lower grade (1 g/t cut-off) matrix is shown in orange and averages a much wider 18 m thickness.

Extraction from the Milagros mine began in January 2016 and by December 2017, a total of 307 kt had been mined at a milled head grade of 0.32% Cu, 1.43 g/t Au and 0.59 g/t Ag.

The MAP technical team’s unofficial view of the orebody is that the combination of the high grade core and the low grade matrix totals 15 Mt. A total of 3 Mt has already been mined, leaving 12 Mt for future exploitation, of which perhaps 25% could be converted to a reserve. Thus, the operators believe that a 3 Mt orebody is possible from the Milagros Mine. This has not been confirmed.

The mine comprises numerous lenses including the Diabla, Sucia, Daniela, Divina and Dura. The MAP technical team believes that there is a good opportunity to drill and find additional resources in some of these lenses that include an unmined high grade core.

The Los Mantos open pit is directly above and north of the Milagros mine.

The Los Mantos pit abuts both the processing plant and the tailings impoundments. A LOM plan will be impacted by these facilities, as it is unlikely to warrant relocating either.

Surface haulage from the outlying properties is accomplished using 20 to 25 tonne (t) highway trucks.

The plant is a conventional three stage crushing with single stage ball milling and bulk flotation to generate a concentrate of combined copper-gold with silver as a byproduct. It is then dewatered on site and trucked to either Glencore’s Chilean Altonorte smelter, or to the port, for dispatch to the market.

The property contains a mill that is permitted to operate at 3000 Mt/d, with an allowance to exceed the permitted capacity by an additional 20%, suggesting a maximum allowable milling rate of approximately 3,600 Mt/d.

Crushing
Run-of-mine (ROM) mineralized rock is delivered to the coarse stockpile as separate material for evaluation and assaying prior to being blended through the plant. ROM mineralized rock is control discharged from the 50 t ROM bin by a grizzly feeder ahead of a 56” x 48” Nordberg C140 Jaw crusher. ROM fines at nominally minus 150 mm by-pass the jaw crusher and are conveyed with jaw product at nominal 200 mm to the secondary crusher.