The epithermal gold-silver deposits at La Libertad and Pavón can be assigned to the low sulphidation subclass of deposits while the gold-silver-base metal vein systems at the EBP belong to the intermediate sulfidation sub-class of deposits. All the major veins identified on the Pavón concessions are hosted by intermediate to felsic rocks within the Matagalpa Group sequence. Rhyolite tuffs and flows overlying the sequence appear to be syn- to post-mineral and have been mapped regionally as part of the Lower Coyol Group. Gold-silver mineralization at Pavón is hosted within quartz veins, and stockwork veinlets, and quartz vein breccia with textures and alteration assemblages typical of formation in a low sulphidation epithermal environment. Many of the veins display multiple stages of quartz deposition and both tectonic to hydrothermal brecciation. Brecciated veins are more common than massive fissure veins in the Pavón area. Quartz vein textures vary both within individual veins, and between veins across the concession. Common quartz textures include granular (locally gray with fine grained disseminated pyrite), massive, and banded clear, grey, and blue chalcedonic. Coarsely crystalline or massive quartz, cockscomb, and cockade textures are less common suggesting most of the multi-phase quartz was deposited at lower epithermal temperatures (Hawksworth, 2005). Adularia is an important vein component of the Pavón Norte, Pavón Central, and Pavón Sur deposits. It occurs as m ........

The Pavón open pit mines are subdivided into two zones; Pavón Norte, an active open pit, and Pavón Central currently not under operation. Mining will be undertaken by contractors using conventional truck and loader equipment.

Pavón Central included in the mine plan will require a waste mining phase commencing with Pavón Central Starter Pit in Q4 2022 to expose the initial ore for production (pre-stripping). Mine production will consist of up to 1.6 Mtpa and 2.5 Mtpa (ore and waste) for Pavón Norte and Central respectively over a 4.5 year mine life.

Open pit mine design criteria are based on a conventional surface mine operation using 3.5 m3 backhoe excavator for loading a fleet of 36 t capacity trucks. Mining at the Pavón Norte pit will be accomplished in two phases to achieve the final pit limits. The current operating main pit will be mined to the bottom. In addition, Pavón Norte North pit will be mined.

A bench mining height of six metres was used, matching the vertical dimension of the reserve blocks. Pit walls are designed with berms at 12 m intervals (i.e., double benched). The pit ramps were designed at 10% maximum gradient for the largest hauling equipment. For single lane traffic, the minimum overall width, including shoulder berm and ditch, is 12 m. For the last benches of the ramp in the pit bottom, the haul road is narrowed to a width of 10 m, manageable for single lane traffic.

The Open Pit LOM production represents a c ........

Ore is reclaimed from the run of mine (ROM) and reclaimed heap leach stockpiles and fed to two jaw crushers operating in parallel using front end loaders. A 400 tonne per hour (tph) crusher for the ROM material and 200 tph crusher for the reclaimed heap leach material. The crushed material discharging from each of the crushers is combined on a crushed ore stockpile. Ore is reclaimed from the crushed ore stockpile using a front end loader and dumped into the SAG mill feed bin and apron feeder and conveyed to the SAG mill feed chute.

The grinding circuit comprises a conventional open circuit SAG mill with pebble crushing, followed by closed circuit ball milling. Crushed material is fed to a single 20 ft diameter by 9 ft effective grinding length (EGL) SAG mill with discharge trommel oversize pebbles recycled through a cone crusher to the SAG mill feed. Trommel undersize slurry flows by gravity to the cyclone feed pumpbox and combined with the ball mill discharge slurry is pumped to a cluster of hydrocyclones (cyclones) for classification. The cyclone underflow slurry flows by gravity to two 13 ft diameter by 20 ft EGL ball mills operating in parallel. The SAG mill and ball mills are driven by identical 1,680 kW motors. The target particle size distribution in the cyclone overflow slurry is 70% passing 75 µm.

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