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.

Placers are present on the Project 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 is an approximately 16-year LOM operation including the preproduction 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 0.35 g/t gold COG. All Inferred Resource materials are treated as waste in the pit optimisation. The mill feed is made up entirely of Measured and Indicated Resource materials (laterite, saprolite, transition and sulphide) 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 8, the process plant will be fed mainly with high-grade oxides from the pit and supplemented by the ROM stockpile.

From Year 9 to Year 11, the process plant will be fed mainly with high-grade sulphides from the pit and supplemented by the ROM stockpile.

From Year 12 to Year 16, the process plant will be fed with material from the low-grade stockpiles exclusively, using a front-end loader and articulated trucks.

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: 15.6 m, to accommodate two-way traffic;
• Ramp gradient: maximum 10 %;
• Working areas: a minimum of three independent working areas, based on the mine schedule.

Final Pit Design
The ultimate pit is approximately 4.3 km long, with a maximum width of 500 m and a maximum depth of 180 m. This pit is composed of several sectors, and each sector is accessed via one of the four main access ramps. All the access ramps daylight at an elevation between 375 m and 405 m. The mill is located East of the Pit.

The crushing circuit will be constructed in two phases: the first phase will be to treat oxide ore only, followed by a second phase later in the life of mine (LOM) to treat sulphides and/or a blend of sulphides and oxides. When treating oxide ore, only the primary crushing stage will be in use while three crushing stages will be required when treating the sulphide ore.

The milling circuit will also be implemented in two phases: the first phase will consist of a single stage ball mill to treat oxides while the second phase will consist of an additional secondary ball mill, which will be installed in the later part of the LOM to treat sulphides.

Crushing and Mill Feed Storage
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 dialtype speed controller.

For the oxide ore, 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.

For the sulphide ore:
• The crusher product joins the apron feeder fines on the sacrificial conveyor. The sacrificial conveyor diverts the ore to the secondary crusher screen feed conveyor, which transfers the material onto the secondary screen. The secondary screen oversize reports to the secondary cone crusher feed bin. The material is withdrawn from the bin using a pan feeder, which is controlled to choke feed the secondary cone crusher. The secondary crusher product reports to the tertiary screen feed conveyor where it combines with the secondary screen undersize and tertiary crusher product.
• The tertiary screen feed conveyor transfers the material to the tertiary screen. The screen oversize discharges into the tertiary crushers’ feed bin. The material is withdrawn from the bin via pan feeders in a controlled rate to ensure a choke feed condition in the tertiary cone crushers. The tertiary cone crusher product reports onto the tertiary screen feed conveyor.
• The tertiary screen undersize discharges onto the tertiary screen undersize conveyor, from where it is transferred to the primary crusher transfer conveyor, which transfers crushed ore either to the mill feed bin or the emergency stockpile.

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 is fed by the mill feed conveyor. The feed to the mill is measured by the mill feed weightometer on the mill feed conveyor.

Milling
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.

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 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 primary or secondary ball mill when treating oxides and sulphides, respectively.

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 Kobada gold processing plant is designed to process oxide ores from the three main deposits: the North, South and Central ores during the first years of production followed by sulphides when the oxides are depleted. The process plant design utilises a combination of CIL and gravity recovery technologies to recover gold. Gravity gold is recovered from the cyclone underflow fed to the centrifugal gravity concentrator. The gravity recovery tailings are transferred back to the mill feed for further gold liberation. Gold that is not gravity recoverable is recovered through the CIL process.

The process plant consists of the following sections:
• Primary Jaw Crushing,
• Secondary Crushing and Tertiary Crushing (to be added in future when treating sulphides)
• Mill Feed Storage
• Primary Milling
• Secondary Ball Milling (to be added in future when treating sulphides)
• Gravity Recovery and Concentrate Leach
• CIL Gold Recovery
• Cyanide De ........