Yaramoko is underlain by geology considered to be similar to that of other Birimian-age volcano- sedimentary sequences. Hence, this region is considered prospective for orogenic gold deposits, which typically exhibit a strong relationship with regional arrays of major shear zones.

Gold is the main mineralization of economic interest found to date on the Yaramoko property. The main areas of gold mineralization are the 55 Zone, Bagassi South, 109, and 117 zones. The 55 Zone and the Bagassi South zones are the two main zones, both of which are hosted in the Diebougou granitoid domain.

The 55 Zone occurs in a reverse dextral shear zone and gold is primarily associated with quartz veining. The bulk of the gold mineralization occurs in dilatational segments of the shear zone where quartz veins are thicker and exhibit greater continuity. Gold typically occurs as coarse free grain in quartz and is associated with pyrite. The gold-bearing veins range from a few centimetres to more than 4 m in width, and have only minor contents of disseminated pyrite (frequently less than 1%). Adjacent sheared vein wall rock locally contains a small percentage of pyrite.

The Bagassi zone is an area of artisanal prospecting located south of 55 Zone that yielded positive geochemical results. At Bagassi South the mineralization consists of pyrite hosted in quartz veining. The surface definition of the vein can be traced by the artisanal mining. The vein is discontinuous over a strike length of some 800 m and is believed to dip to the southwest. Gold mineralization at Bagassi South is associated with quartz, white mica and pyrite alteration.

Four mineralogically distinct hydrothermal veins were defined: 1) quartz-rich veins, 2) iron- dolomite rich veins with quartz and muscovite, 3) iron-dolomite and quartz veins with albite, and 4) albite-rich veins with quartz and iron-dolomite (GeoMinEx, 2013). Native gold is present in each vein type, with accompanying sulphides mainly as pyrite and traces of tellurides. The most abundant sulphide mineral, pyrite, occurs in veins, altered wall rock. Textural and chemical complexity of pyrite document protracted period of crystallization from a compositionally evolving hydrothermal fluid. Native gold occurs in numerous textural associations and at a wide range in grain size ranging from less than 1 and up to 300 micrometres.

The second type of gold mineralization encountered is also associated with pyrite, occurring in zones of conspicuous shearing primarily in the volcanic rocks, with minimal to no significant quartz veining. These two styles of mineralization represent two end-members of brittle-ductile deformation within the 55 Zone where coarse gold in veining, usually seen in a granitic host, defines a more brittle environment while pyrite and shearing in the volcanic rocks is typical of a ductile domain.

The relevant characteristics of 55 Zone from a mining method selection perspective are provided below.

It is a steeply dipping shear-hosted quartz vein. At depth the vein structure is comprised of a broader shear zone involving quartz veining that is more broken up;

The vein has an average true in situ thickness of 4 m, ranging from 2 to 12 m;

It is a relatively high grade deposit with good continuity at a 5 grams of gold per tonne (g/t gold) cut-off grade;

95% of the economic mining value of the deposit occurs above a depth of 281 m; and

The weathered layer above the bedrock surface varies in thickness from 10 to 30 m, and extensive artisanal workings have been excavated in the layer.

Longhole open stoping (including up hole retreat) is the main mining method with cut and fill being the only exception. All of the methods except up hole retreat will employ waste rock as backfill.

The main vein and splay vein exhibit regular geometry at stope scale, and along with the steep dip and competent rock strengths, permit a longhole open stoping method with delayed backfill. The narrow nature of the vein dictated a small hole size for production blasting with a 64 mm diameter hole size selected. The small hole size selected and relatively narrow vein thickness limited the sublevel spacing to 17 m sill to sill, to limit the impact of hole deviation on external dilution. An assessment of rock mass strength and weakening structures provided guidance on the stope size selected; 25 m strike length and two sublevels in height (total 34 m open stope height).

A longitudinal stope mining sequence, along strike from vein extremities to ramp access points is planned. The mine layout includes two separate ramp systems through the main body of the mine to break up the 600 m plus strike length (minimize mucking distances) and to provide additional independent mining fronts.

Ore development on vein will be limited to a maximum width of 5.0 m. Blast holes will consist of parallel down holes 14 to 16 m in length. Some drill holes will be fanned out where vein widths exceed 5.0 m. Drill factors range from 2.7 tonnes/metre (t/m) at the minimum stoping width of 2.2 m to 4.9 t/m, averaging 4.1 t/m.

Blast holes will be loaded with either ANFO or emulsion to an average powder factor of 0.50 kilograms per tonne depending on local water conditions. Slots will be opened by drop raising.

Standard stope dimensions are 25 m on strike, 34 m height, and vein width. At an average in situ true vein width of 4.0 m, a standard stope will yield 11,200 tonnes including the development tonnes.

Production mucking will be undertaken by 10-tonne capacity LHDs for 60% of the planned stope tonnage. Smaller LHDs will be used for stopes in the narrow sections of the vein. Ore mucked from draw points will be trammed to remuck bays located on each level close to the main ramp.

Generally all stopes will be backfilled with 4.0% cemented development waste rock, supplemented by a dedicated backfill rock quarry on surface late in the mine life. Waste rock will be mixed with cement slurry at a backfill mixing station planned on 5236 level. CRF will be hauled by truck to the vein then trammed by LHDs along vein to the stope dumping point on the upper drilling level.

Up hole stoping will progress in a retreating sequence along strike, matching the timing of the stope block below. The up hole stopes will not be backfilled. SRK’s geotechnical assessment indicates that the 14 m span of hangingwall will remain stable over the strike length of the planned mining. The 14 m stope height was selected to achieve highly reliable up hole ore recovery (short blast holes), and to meet the geotechnical requirement for hangingwall stability. Slot raising to initiate ring blasting will consist of inverse raises.

Two mining methods were selected for crown pillar mining above the 5270 elevation; mechanized cut and fill (MCF), and up hole retreat stoping (similar to the preceding description).

The goal of the mine plan is to recover all of the very high grade gold mineralization located in the crown pillar. The final mining will be an up hole retreat using 10 to 15 m blast holes of 64 mm diameter. Mechanized cut and fill with waste rock backfill is planned as a first step to advance to an appropriate elevation for drilling the up holes.

The process flow diagram has been developed from the process design criteria prepared by Mintrex. The plant design proposed is simple and robust. -
The gold recovery system comprises the following:
- Primary crushing;
- Grinding–Single-stage SAG mill;
- Classification;
- Gravity concentration and intensive leach reactor ;
- Leaching and adsorption (CIL);
- Tailing thickening;
- Electro-winning; and
- Smelting.

The process plant is designed for a throughput of 270,000 tonnes per annum. The proposed plant site is located at 315 m above sea level. It will be positioned next to the underground portal to minimize ore haulage costs.

The proposed plant is designed to achieve the required throughput to meet the requirements as defined in the material flow property testwork completed by Jenike and Johnson Pty Ltd. (2014). The plant design is a combination of the following circuits:

- A crushing circuit with a throughput of 50 t/h and availability of 70%, on a 24 hours per day operation;
- Crushed product will report to an open stockpile, which has live capacity of 810 tonnes. An underlying apron feeder and emergency vibrating feeder will provide ore feed directly to the milling circuit;
- A milling circuit with a throughput of 33.75 t/h, operating at 91% availability, and aiming to achieve a design grind of 80% passing 90 µm;
- A gravity circuit on cyclone underflow consisting of two centrifugal concentrators and an
intensive leach reactor for treatment of the gravity concentrate, treating 70% of the cyclone
underflow;
- A carbon-in-leach (CIL) circuit consisting of one leach tank and five adsorption tanks, treating the cyclone overflow;
- A metal recovery and refining circuit consisting of an elution circuit, electrowinning cells, and smelting; and
- A tailings storage facility for tailings disposal.

The gold sludge from the gravity circuit and the elution circuit electrowinning cells will be filtered with a filter press, 50-FL-01, to remove the water content. It then will enter the calcine oven, to remove steel wool cathodes by oxidation. The product from the calcine oven will be direct smelted using fluxes in a diesel powered smelting furnace, to produce the final gold product: doré bars. These will be weighed using a Sartorius Balance, and stored in the gold safe, located inside a concrete vault. The gold sludge from the gravity circuit will be refined separately from that of the elution circuit to allow for separate accurate metallurgical accounting of the gravity circuit.