DEPOSIT TYPES
Three types of gold occurrences may be expected at Kobada:
• Primary lode gold mineralisation, associated with quartz veins and fault zones related to one or several Eburnean deformation phases (orogenic gold, shear zone gold or mesothermal gold deposits). Deposits of this typeoccur in the surrounding area.
• Lateritic deposits, resulting from the climatic weathering and alteration of primary deposits with diffusion of the gold into mushroom-shaped red oxidation zones (saprolite).
• Placer deposits, where the gold is associated with large angular fragments of quartz and intensely silicified pyritic rocks in alluvial sand and gravel horizons usually several metres in thickness. These fragments are derived from proximal lode deposits.

On the Project, placers are present and have been worked by artisanal miners for a long time.

The Kobada gold deposit is a quartz-carbonate veined mesothermal, orogenic gold deposit hosted within a greenstone belt. It is located in arenites affected by a geological structure that is oriented northeast along the border of an intermediate intrusive that has basic components. Mesothermal veins are formed at moderate temperature and pressure, in and along fissures or fractures in rocks. They are known for their large size and continuation to depth and, therefore, are a major source of the world’s gold production. Veins are usually less than 2 m wide and often occur in parallel sets. Typical mineralisation includes the sulphides chalcopyrite, sphalerite, galena, tetrahedrite, bornite and chalcocite. Gangue includes quartz, carbonates and pyrite.

MINERALISATION
Gold at Kobada is present in the laterite, saprolite, unaltered rock as sulphides and in quartz veins. There are also placer-style deposits in the region, although these have largely been exploited by artisanal miners. Gold mineralisation was coeval with the hydrothermal events that introduced the regionally common quartz veins. The 20° NE structures are the only regional structures that have been identified on the property, the east-west and low angle features seem to be confined to the mineralised zone in between the discrete shear zones.

Mineralisation at Kobada extends for a minimum strike of 4 km and is associated with narrow, irregular, high-angle quartz veins and with disseminated sulphides in the wall rock and vein selvages. Mineralisation occurs as free gold, whereas in sulphides mineralisation includes the occurrence of arsenopyrite, pyrite and rarely chalcopyrite. Visible gold is not common. Arsenopyrite (up to 5 mm) is localised near vein selvages and as fine-grained disseminated patches within the host rock. Pyrite occurs in finely disseminated patches within the host rocks and as euhedral crystals in the black shale, generally as traces up to 3 % by volume with up to 10 % locally in the wall rock at centimetre-scale intervals adjacent to the quartz veins.

Veins have a milky white colour and are generally discordant, with a thickness ranging from millimetric to sub-metric. Mineralised veins are narrow, high-angle quartz veins that either cross-cut another vein or the main fabric. This indicates that more than one generation of quartz veining is present, with a later phase resulting from remobilisation of gold mineralisation from an earlier hydrothermal event.

The quartz veins at the Project Area strike and dip at various orientations and angles, and three broad populations have been identified:

• 20° NE population parallel to the regional foliation: These veins are consistent between 10° NE and 35° NE, dipping between 60° and 90° E and ranging from 5 mm to 1 m in width. They are often sheared (crack and seal), strongly brecciated and cemented with iron and manganese oxides, and mylonatised in places. They are associated with lowgrade mineralisation (0 to 1 ppm Au).

• E-W population: These include strikes 45° NE to 135 °NE and are concentrated between 80° NE and 110° NE, mainly dipping at 60°to 90° N, with some dipping steeply south. They are 1 mm to 50 cm in width, pinch and swell, are relatively discontinuous and can be sigmoidal. Stockwork zones up to 3 m in width can be formed. These veins display a fracture cleavage, which is commonly stained with red iron oxides. They are often surrounded by 5 mm to 10 cm wide limonitic alteration zones that are often wider than the veins themselves. Locally, they are folded in open folds. The veins cross-cut the foliation-parallel veins and are not as intensely deformed as the latter. They are well mineralised (1 ppm Au to 17 ppm Au within the mineralised envelope). These veins may have formed as extensional fractures and/or Riedel shears in the Kobada Shear Zone, with a possible dextral (right lateral) shear sense.

• Sub-horizontal population: These veins display dips ranging from 0° to 30°, with varying strike directions. The veins vary from 1 mm to 10 cm in thickness and often occur as stockworks and ladder vein systems. They can form long continuous crosscutting features and are moderately mineralised (1 ppm to 2 ppm Au within the mineralised envelope) with barren stockwork zones.

The Kobada Open-Pit Project isan approximately 10-year LOM operation including the pre-production period. The mine will need to support a processing plant with a nominal mill feed of 3 Mt/a of ROM.

The mineralised material contained within the final pit design has been determined based on a 0.37 g/t gold cut-off grade (COG). All Inferred Resource material and sulphide (fresh rock) ore are treated as waste in the pit optimisation and in the Mine Schedule as it is not anticipated that any sulphide ore will be processed at this stage. The mill feed is made up completely of Measured and Indicated Resource materials (laterite, saprolite and transition) above the calculated COG.

The Kobada Gold Mine lends itself to a standard open-pit mining method using articulated trucks and a hydraulic loader (hydraulic shovel or excavator).

Approximately 90 % of all the materials to be mined is contained in the saprolite and laterite. Although this type of material can be extracted directly with excavators without drilling and blasting, it has been estimated that approximately 5 % of this material will require some drilling and blasting. All transition and fresh rock material must be drilled and blasted.

The first six months will be exclusively dedicated to pre-production without feeding the process plant.

From Year 1 to Year 5, the process plant will be fed with material from the pit and supplemented by the ROM stockpile.

From Year 6 to Year 10, the process plant will be fed with material from the stockpile exclusively, using a front-end loader and articulated trucks.

The mine design for the Kobada Project consists of a series of nested conventional open-pit layouts with orebody access provided through a series of ramps.

For mining purposes, the Kobada orebody can be considered a top-down layered sequence
of the following material types:
• Laterite
• Saprolite
• Transition
• Sulphide.

Design Criteria
The key design criteria used to develop the pit design are summarised as follows:
• Nominal bench height: 5 m, double benched when possible for final pit walls
• Overall slope angle: 40°
• Road width: width to accommodate two-way traffic and ample passing lane
• Ramp gradient: 10 % or less
• Working areas: a minimum of three independent working areas, based on the mine schedule

Final Pit Design
Based on the selected pit shell generated by Whittle, the final pit design has been split between a North Zone, a Central Zone and a South Zone.

The main pit in the Central Zone is approximately 2.6 km long, with a maximum width of 500m and a maximum depth of 185 m. This pit is composed of three sub-sectors (three “roots” deepening in three areas of the main pit), and each sector has its own ramp to access it independently. All the access ramps daylight at an elevation of 391 m.

The process plant facility is located approximately 500 m from the exit point of the ramp coming from the Central Zone.

Approximately 600 m north of the Central Pit, the North Zone is composed of three smaller satellite pits. The biggest satellite pit is approximately 380 m long, with a maximum width of 130m and a maximum depth of 45 m. The North Zone is located approximately 1.5 km from the Process Plant facilities.

Similarly, located approximately between 200 m and 600 m south of the Central Zone, the South Zone is composed of two smaller satellite pits. They are approximately 350 m long, with a maximum width of 250 m and a maximum depth of 75 m. The South Zone is located approximately 2.0 km from the process plant facilities.

Crushing and Mill Feed Storage
The Kobada crushing circuit consists of a single-stage primary crusher. The ore is fed into the ROM bin using a front-end loader or by direct tipping from haul trucks. An apron feeder, located under the ROM bin, is used to withdraw ore from the bin at a controlled rate and discharges onto a vibrating grizzly feeder to scalp off fines ahead of the primary jaw crusher. The vibrating grizzly feeder oversize material gravitates to the primary crusher while the scalped fines drop onto the sacrificial conveyor. The feed rate to the primary crusher is controlled by varying the speed of the apron feeder using a locally mounted dial-type speed controller. The crusher product joins the apron feeder fines on the sacrificial conveyor. The sacrificial conveyor feeds onto the transfer conveyor, which transfers crushed ore either to the mill feed bin or the emergency stockpile.

A weightometer on the bin feed conveyor measures the material flow rate through the crushing circuit. The weightometer is used to control the rate of crushing and for metallurgical accounting purposes.

Normal feed to the milling circuit is by direct feed from the primary crushing circuit through the mill feed bin (surge bin). The ore is withdrawn from the mill feed bin using the mill feed apron feeder. The mill feed is provided by the mill feed conveyor.

The feed to the mill is measured by the mill feed weightometer on the mill feed conveyor.The feed to the mill comes from the emergency stockpile if the crushing circuit is offline for maintenance or on mechanical breakdown. The ore from the stockpile is reclaimed using a front-end loader for feed into the mill through the emergency ore bin. The emergency apron feeder is used to withdraw the ore from the emergency bin onto the mill feed conveyor.

Dust control is very important in the crushing and mill feed storage sections. Dust control is by way of both containment and suppression. Dust control conveyor skirting, dust enclosures, and dust suppression systems are included in the design as a means of containing the dust produced from the crushing section. The dust suppression system uses fine water sprays at the main dust-generating points in the crushing, stockpile and mill feed sections.

Electric hoists are included in the crushing section to facilitate maintenance.

Primary Ball Milling
The milling circuit consists of a single-stage primary ball mill. Crushed ore is conveyed from the mill feed bin to the ball mill. The ball mill has a variable speed drive, which allows the power input to the mill to be varied when requiring different milling energy inputs.

Tailings return water is the primary source of process water, used for mill feed dilution and cyclone feed dilution. Fresh raw water is only used as a top-up to the process water if there is insufficient tailings return water for the process requirements. The mill feed dilution water is ratio controlled to the mill feed rate to maintain the required mill discharge density. Mill feed dilution water is measured by a magnetic flowmeter on the process water line feeding the water into the mill feed chute.

The ball mill product discharges through the trommel screen, which removes the oversize scats. The scats produced from the ball mill are discharged from the trommel screen into the scats bund. A front-end loader periodically picks up and deposits the scats onto the emergency stockpile. The scats are reclaimed and fed back into the milling circuit using a front-end loader.

The undersize from the trommel screen gravitates to the mill discharge sump. The mill discharge slurry is diluted to the required density in the mill discharge sump, and the dilute mill discharge slurry is pumped to the cyclone cluster by either of the cyclone feed pumps. The pumps are equipped with variable speed drives.

The cyclone underflow gravitates into the gravity splitter box. A portion of the cyclone underflow is directed to feed the gravity gold recovery circuit. The balance of the cyclone underflow reports back to the ball mill. The cyclone overflow gravitates onto the vibrating trash screen. The trash screen removes the trash oversize material (such as misplaced oversize particles, vegetal debris, plastic fragments, blast fuses, and wires) from the cyclone overflow stream before it gravitates into the CIL feed box. The trash oversize material discharges into a trash basket. Process water drains through the trash basket and gravitates to the spillage bund. The undersize from the trash screen gravitates into the CIL feed box, which feeds the first CIL tank.

The milling area is bunded to contain spillage and is equipped with two spillage pumps: one at the mill feed end, and one at the mill discharge end.

Grinding media (steel balls) are added to the ball mill by the ball loading kibble. The hopper is lifted by the crane onto the grinding media feed chute. The mill balls are discharged into the mill via the mill feed hopper by lowering the ball loading hopper to its rest position located directly above the mill feed chute.

The proposed process plant design is based on a well-known and established gravity/CIL technology, which consists of crushing, milling, and gravity recovery of free gold, followed by leaching/adsorption of gravity tailings, elution and gold smelting, and tailings disposal. Services to the process plant will include reagent mixing, storage and distribution, water and air services.

The plant will treat 3 Mt/a of saprolite ore or a blend of saprolite and laterite ore in a 90/10 split, respectively.

• Single-stage crushing facility utilising suitable primary crushing technology (such as mineral sizeror jaw crusher)to treat the soft saprolite and laterite ores.
• Single-stage ball mill operating in an overflow arrangement with a ball-retaining ring to retain the media and reduce scatting
• Gravity recovery and intensive cyanidation
• CIL (six CIL stages with no pre-leach tank to mitigate the preg-robbing properties of the ore)
• INCO air/SO2cyanide ........