Romero is located on the south side of the Central Cordillera of Hispaniola and is hosted by the Cretaceous-age Tireo Formation volcanic rocks and limestones, which formed in an island arc environment. The deposit geology is a relatively flat lying sequence of intercalated subaqueous, intermediate to felsic volcanic and volcaniclastic rocks and limestones on the west side of thick rhyolite flows or domes. Mineralization is relatively stratabound and flat lying and is mainly hosted by a dacite breccia tuff.

Mineralization outcrops in a number of places were eroded by rivers and streams, and continuity under barren cap rock has been demonstrated by drilling. Hydrothermal alteration and gold mineralization can be traced for over 2,200 m from Romero to Romero South and beyond to the south.

The thickness of the altered dacite tuff breccia horizon is up to about 65 m at Romero South and up to more than 200 m (open) at Hondo Valle and Romero. The mineralized horizon is capped by limestone or dacite to andesite lavas.

Mineralization is intermediate sulphidation epithermal in style. The mineralization is associated with quartz-pyrite, quartz-illite-pyrite and illite-chlorite-pyrite alteration. Alteration is generally strongest in the upper part of the mineralized zone and decreases in intensity with depth. Gold mineralization is associated with disseminated to semi-massive sulphides, sulphide veinlets and quartz-sulphides. The sulphides comprise pyrite with sphalerite, chalcopyrite and galena. Oxidation is shallow, to a depth of 10 m to 15 m.

High grade mineralization at the Romero deposit takes the shape of vertically stacked sub-parallel irregular lenses which generally dip to the northeast at an average angle of 20°. Each lens ranges in thickness from 10 m to 40 m in the middle and generally tapers to zero width at the edges, but the continuity of the lenses in all directions is inconsistent. The spacing between lenses is also inconsistent and ranges up to 50 m. Generally, lower grade mineralization surrounds the higher grade lenses.

The strike length of the main portion of the mining resource is 430 m. Two smaller pods of high grade mineralization exist approximately 200 m along strike to the southeast of the main larger main economic body. The deepest mining level is 420 m below surface (680 m level) and the highest mining level is 85 m below surface (1,000 m level), meaning the total vertical extent of the mining resource is 320 m. Perpendicular to strike, the deposit is about 170 m wide.

Two mining methods are proposed for the Romero deposit, sub-level long hole (LH) stoping and mechanized cut and fill (MCF). A combination of paste backfill and develop waste rock fill will be used in mining sequence. LH stoping will be used in areas of complete ground strength and generally thick Mineral Resources. MCF will be utilized in the areas of pour ground conditions and/or thin Mineral Resources which does not warrant LH stoping.

Long hole (LH) stoping provides high productivity at low cost from a small number working faces. All stopes will be fixed with a mixture of paste fill and/or development waste.

Geotechnical design have determined stope sizes of 30 m along strike, with widths up to 15 m wide and sub-level intervals of 20 m. Stope extraction sequencing is planned to be in a primary-secondary fashion with the lower stopes leading the stopes above. Primary and secondary stopes are sized equally at 15 m wide. After the primary stopes are mined, they will be filled with cemented paste backfill of adequate strength to allow exposure of 20 m high x 30 m long fill wall adjacent to the secondary stopes that will be mined alongside. Two lifts of primary stopes will be mined before the first secondary stopes are started to allow the drilling drifts to be reused as mucking drifts for the next sub-level above and to minimize the stoping span.

LH stopes will be developed by driving a central ore drift up to a mineralization thickness to a maximum 5 m by 4 m hight access drift central to the stope.

A slot raise will be developed at one end of the stope by LH drilling and short stage blasting from the bottom up using the drop-raise blasting techniques. The slot raise will be enlarged to form a slot across the full width of the stope.

Vertical ring of drill holes will be blasted into the stope and mineralized material will be mucked from the bottom of the stope by load-haul-dump (LHD) machines with remote control.

No rib pillars were planned and the stoping sequence with the paste backfilling will allow 100% extraction in the LH stoping blocks.

Mechanized cut and fill mining will be utilized in thinner areas where LH stopes are not economic. MCF will also used in areas of poor ground conditions where larger stope are not geotechnically possible. MCF is a lower productivity, higher cost mining method than LH stoping, but provides highly selective mining with minimal dilution. Stopes can be sized with irregular back and walls to match the ore boundaries.

A two boom, electric hydraulic jumbos will drill 4.88m (16 foot) long rounds on a standard development heading pattern. The drilled holes will be charged with high explosive primers and ANFO and initiated with non-electric caps. After blasting, the heading will be washed, scaled and blasted ore will be mucked with LHDs into trucks and hauled to surface. Ground support will then be installed with a mechanized bolter as required.

Two types of MCF will be utilized at Romero. Overhand MCF accounts for 73% of MCF mining, and 11% of all production. In overhand MCF each mining block is accessed by an attack ramp and mined in 4 m high lifts. Stopes are developed on the lowest level first, and each subsequent stope or 4 m lift is developed above the depleted and backfilled stope. Mining direction is bottom up.

Underhand MFC accounts for 27% of MCF mining, and 3% of all ore production. In underhand cut and fill an MCF stope is mined out and backfilled with a high strength structural paste fill, after it has been prepared with additional ground support on the floor. Once the structural paste fill has cured the next 4 m lift will commence underneath the filled stope. Mining direction is top-down.

The requirement of both mine methods is a byproduct of optimizing the LH stope production schedule, and avoiding the requirement to mine through backfilled areas to gain access to MCF zones.

The flowsheet consists of primary crushing, SAG and ball mill grinding, gravity separation, flotationm dewatering and filtration. Tailings will either be dry stacked or combined with cement and pumped underground as paste backfill.

The concentrate will be transported to designated smelters worldwide for subsequent reduction into copper metal. Mill throughput is designed to be approximately 2,800 dry tonnes per day (dt/d). Total annual concentrate production will be approximately 64,000 t.

The mineral processing facility will be located south of the Romero mine site. Listed below are the major process unit operations at Romero:
- Primary jaw crusher;
- Crushed stockpile (live capacity 2,800 tonnes);
- Conveyance of material from the crusher building to the stockpile and onto the main process facility;
- Mill building will contain:
o Semi-autogenous grinding and ball mills and gravity concentration within closed circuit cyclone classification;
o Copper flotation and concentrate regrinding via stirred mill;
o Copper concentrate dewatering through thickening and filtration;
o Process water, fire water, potable water distribution;
o Reclaim water distribution;
o Utility air distribution;
o Tailings dewatering through thickening and filtration;
o Concentrate load-out; and
o Reagent storage and reagent mixing.

The primary jaw crusher will be located near the process plant. Mineralized material will be delivered by truck from the underground portal and rehandled by a front-end loader into a jaw crusher. Feed will be crushed to a nominal product size of approximately150 mm at 80% passing (P80) and conveyed to a 2,800 t live stockpile.

The primary grinding will consist of one SAG mill with pebble crusher followed by primary screening. The secondary grinding circuit will consist of a ball mill and gravity concentrator operating in closed circuit with the cyclones.

The cyclone overflow, at approximately 31% solids, and a particle size of (P80) 75 microns, will flow by gravity to the flotation circuit. Copper concentrate will be produced with conventional froth flotation in a typical rougher and cleaner configuration.

The copper rougher concentrate will be reground in a stirred mill to produce a particle size of (P80) 23 microns.

The flotation concentrate and gravity concentrate products will be combined and dewatered in high rate thickeners with the under flow feeding filter feed stock tank. A dedicated pressure filter will dewater the concentrate to a moisture content of approximately 8%.

The copper concentrate will be loaded into trucks by front-end loader and transported to the port for shipment to off-shore smelters/refineries for further processing.

The tailings will be thickened and filtered for either deposition as dry stack tailings or paste backfill underground.

The process plant will operate with 100% reclaim water from the thickener overflows to meet the process water requirements. Fresh water will be required for gland seal and reagent mixing.