The Project consists of four (4) deposits, Malikoundi/Boto 2, Boto 5, Boto 4 and Boto 6, all of the late orogenic type.

At Boto, the material near the surface consists of a layer of regolith which is varying in thickness and includes lateritic plateaus. Few rocky outcroppings are visible in the property; the banks of streams and rivers serve as the main source for geological observations. Only drilling can provide a detailed knowledge of the geology below surface. Drilling data and geological interpretation were used to create a regional representation of Boto geology.

Boto can be divided into three north trending litho-structural domains (020° N) that are well delineated in both induced polarization (IP) and magnetic surveys. From west to east, the three domains are:
• Western Flyschoid Domain.
• Central Deformation Corridor.
• Eastern Siliciclastic Domain.

Malikoundi/Boto2, Boto 4, and Boto 6.
At Malikoundi/Boto 2, Boto 4 and Boto 6, the regolith is composed of pedolith (soil, ferricrete, and laterite), saprolite, and transition weathering profiles (saprock) that average 8 m, 20 m, and 10 m in thickness, respectively. The detailed study of regolith has made it possible to distinguish between transported and in-situ regolith. The assay results from up-dip expressions of mineralized zones, confirm in-situ mineralized regolith. Mineralization in fresh rock is mainly associated with pervasive albite alteration and pyrite.

Interpretation of structural data collected from oriented drill core has shown differences between Malikoundi/Boto 2, Boto 4, and Boto 6. Boto 6 is characterized by a bedding strike of 025° N, whereas Malikoundi/Boto 2 appears to have two bedding strike directions of 015° N and 030° N. The two bedding strike directions observed at Malikoundi/Boto 2 may result from ductile deformation within the impure marbles and laminated detrital sediments. Contrary to other parts of the structural corridor, a significant rotation of bedding strike to 147° N is noted in the drill core at Boto 4.

At Malikoundi/Boto 2, a 30° to 60° westward- dipping thrust fault has been observed in drill core at the contact between the Guémédji sandstone and the sequence of marble/laminated sediments. Of particular interest is a large lens of Guémédji sandstone that lies above the fault. This over-riding block of sandstone from the north end, cut out and moved from the Guémédji sandstone unit, is the main host of mineralization in this prospect. As a result of these movements, this lenticular block was severely fractured against adjacent rocks, and this fracturing was the conduit through which the gold-carrying fluids circulated and the mineralization was deposited. Thus, the fracturing associated with the sandstone lens is the principal carrier of mineralization in facies as diverse as sandstone, pelites, agglomerates, cipolin (unclean marble), or sometimes even syntectonic diorite. This overlap/shear fault was also identified further south in Boto 4 and Boto 6, further north of the Falémé River to the Fekola Gold Mine in Mali (called Medinandi permit), owned and operated by B2Gold; as well as further south to the Tammy permit (Mali). Several different units of cipolin were observed and these units played the role of deformation trends as well as permeability barriers to mineralizing fluids. At Malikoundi North, one of the units of cipolin corresponds to the mineralization zone having accommodated the deformation related to the circulation of mineralizing fluids.

Cipolin units can be subdivided into:
• Stratigraphic Cipolin In-situ: these marbles are distorted but remain in their stratigraphic place and are generally thick.
• Cipolin of Re-crystallized Deformation: these marbles are very distorted and re-crystallized and have been spread along shear structures by deformation. They no longer correspond to the stratigraphic orientation, but to a structural orientation usually making the junction between two different stratigraphic cipolins that were thus accommodated; their thickness is generally low, with an average thickness between 2-3 m and only rarely surpassing 10-15 m.

Boto 5.
The weathering profile of Boto 5 is considerably deeper than that of Malikoundi/Boto 2, Boto 4 and Boto 6. Boto 5 is covered with a layer of pedolith 10 m to 40 m thick under which the saprolite layer can reach up to 80 m thick. The transitional layer under the saprolite is between 10 m to 40 m thick.

The lithological units at Boto 5 strike 015°-020° and include shale, carbonaceous sediment, and basalt. An albitealtered diorite dike that hosts the mineralization at Boto 5 cross-cuts the stratigraphy, striking 045° N dipping between 45° W and 60° W towards the west, approximately 30 m wide, and containing fragments of host rock in places.Four deformation phases occurred at Boto 5. An early phase of brittle-ductile deformation led to the emplacement of barren tourmaline veins. This was followed by reverse brittle-ductile faulting overprinted and reactivated on the northeast trending structures. Gold-bearing quartz-tourmaline veins were formed during this phase. The D2 structures were subsequently covered by a third ductile deformation phase. The latest deformation event is characterized by north-northwest and northeast trending brittle faults that offset the mineralization into blocks.

Similar to the majority of the deposits found in the Kédougou-Kéniéba inlier, gold mineralization at Boto is considered to be of the orogenic type. The orogenic gold deposits in the Birimian Province have been classified into three groups (Pre-, Syn-, and Post-orogenic). The characteristics of Boto mineralization are more similar to those of the post orogenic class.

The Malikoundi/Boto 2, Boto 4 and Boto 6 deposits are hosted by a turbiditic sedimentary sequence, with mineralization concentrating along the contacts of the litho-structural domains. The association of orogenic deposits with turbiditic sequences is well documented by Poulsen et al. (2000). Turbidite-hosted gold deposits within the
eastern Kédougou-Kéniéba inlier are controlled by north-northeast trending structures linked to the SMSZ and, occur within the vicinity of intersecting north-northeast and north-north-west structures. At the Malikoundi/Boto 2, Boto 4 and Boto 6 deposits, gold is typically associated with pyrite, which is either disseminated along fractures (crackle-breccia hosted type) or along brittle-ductile veins.



Alteration assemblages observed at Boto 5 differ from those observed at Malikoundi/Boto 2, Boto 4, and Boto 6. The Boto 5 deposit is hosted in a diorite dike that contains abundant endogenic albite or has been pervasively altered to albite. The host rock at Boto 5 is highly deformed and contains a stockwork of quartztourmaline-pyrite veins. Although differing in appearance, this style of brittle- ductile deformation and veining is consistent with an orogenic gold mineralization model.

Open pit mining was selected as the method to examine the development of the Project located in Senegal. This is based on the size of the resource, tenor of the grade, grade distribution and proximity to topography for the Malikoundi and Boto 5 deposits.

While resource models were developed for Malikoundi, Boto 4, Boto 5 and Boto 6 only the Malikoundi and Boto 5 models were used for the Feasibility Study mine plan.

Pit designs were developed for the Boto pit areas – Malikoundi, Malikoundi North and Boto 5 pits. The pit optimization shells used to determine the ultimate pits were also used to outline areas of higher value for targeted early mining and phase development.

Geotechnical berms of 12 m to 20 m in width were designed in the Malikoundi and Malikoundi North pits at the base of the weathering (transition) zone. For Boto 5, flatter slopes on the hangingwall material were recommended and ramps were incorporated in this material to act as geotechnical berms. In addition, a geotechnical berm was recommended at the 150 level in Boto 5 with a width of 30 m.

Equipment sizing for ramps and working benches is based on the use of 95 tonne rigid frame haul trucks. The operating width used for the truck is 6.9 m. This means that single lane access is 21.4 m (2x operating width plus berm and ditch) and double lane widths are 28.3 m (3x operating width plus berm and ditch). Ramp gradients are 10% in the pit for uphill gradients and 8% uphill on the dump access roads. Working benches were designed for 35 m to 40 m minimum on pushbacks, although some pushbacks in the Malikoundi pit did work in a retreat manner to facilitate access.

Boto 5 was envisaged as a contract mining operation using 40 tonne trucks, but the same road and ramp requirements were applied as for Malikoundi.

The Malikoundi pit is designed as 4 phases within the main pit. Phase 0 as the initial pit is called is a subset of Phase 1 to drive quickly to fresh rock for tailings dam construction purposes. Malikoundi North is a single-phase pit as is Boto 5.

Malikoundi.
Phase 0 is a subset of Phase 1 with the purpose of driving quickly to fresh rock for construction purposes in addition to material for road and other infrastructure items. It is the first phase mined in the Project. The Phase elevations range from 165 masl to the pit bottom of 105 masl.

Phase 1 expands on Phase 0 and is also developed from the north and advanced south. It has elevations ranging from 165 masl to a pit bottom of 60 masl. This is primary ore source early in the mine life.The ramp starts further to the north to avoid disrupting material flow from Phase 0.

Phase 2 is also accessed from the north but slightly further than Phase 1. Phase 2 is unique in that it has multiple exits to allow mining from both the hangingwall and footwall at the same time as mining in Phase 1 is advancing. This provides the mine planning team the flexibility to advance one side over the other quickly to accommodate rainy seasons and also the future development of Phase 2. Phase 2 has elevation limits of 165 masl to a depth of -40 masl.

Phase 3 is a deepening of the southern area of Phase 2. This will be a single access phase to save on waste and exits to topography on the south side. The geotechnical berm is evident in the design at the base of the transition zone. The multiple access points of Phase 2 assist Phase 3 by not disrupting material movement from Phase 2 and offer the ability to shorten haul profiles at different times in the mine life. Phase 3 extends from the same 165 masl level to a final depth of -160 masl or 325 m at the deepest point.

Malikoundi North.
The Malikoundi North pit is designed as a separate satellite pit to the north of the main Malikoundi pit. It consists of a single small, narrow mining phase that is accessed with a slot from the north end of the pit. The haul road will be to full operating width, except for the single lane for the bottom benches. This phase is located immediately to the east of the proposed water storage facility. Malikoundi North has an elevation variation from 160 masl to 50 masl.

Boto 5.
The Boto 5 phase was designed as a separate satellite pit to the south of the main Malikoundi pit. It consists of a single mining phase that is accessed with a wrap-around ramp access from the northwest corner of the pit. The haul road will be to full operating width, except for the single lane for the bottom benches. The pit ranges in elevation from 205 masl to 85 masl.

The proposed process facility will consist of the following process areas:
• Primary crushing and coarse ore storage.
• Grinding, utilizing a SSAG circuit.
• Leach-CIP Carousel circuit.
• Gold recovery and carbon handling circuit (consisting of a cold acid wash followed by a pressure Zadra elution circuit and horizontal carbon regeneration kiln).
• Tailings disposal in a lined TMF with natural degradation of residual cyanide.

Ore Receiving and Crushing.
A static grizzly (600 x 600 mm), mounted above the ROM bin, will prevent the ingress of oversize material. A mobile rock breaker will be used to break oversize material retained on the static grizzly. Ore will be withdrawn from the ROM bin, by a variable speed apron feeder, directly into a jaw crusher, which will operate in open circuit. Crushed ore from the crusher will discharge directly onto the primary crusher discharge conveyor, which will convey the crusher product to the mill feed bin.

The crusher discharge conveyor will be fitted with a weightometer, to monitor and control the crushing area throughput by adjusting the output of the apron feeder variable speed drive.

Grinding and Classification.
The grinding circuit will be a SSAG circuit, comprised of a single, variable speed, semi- autogenous grinding (SAG) mill. The SAG mill will operate in closed circuit with hydro- cyclones while pebbles will be removed by a Trommel screen and recycled back to the SAG feed conveyor via two conveyors. The product particles exiting the grinding circuit (cyclone overflow) will contain 80% passing 75µm material.

Leach Circuit.
Pre-leach thickener underflow will be pumped to the leach feed distribution box. The slurry from the leach feed distribution box will discharge into the pre-oxygenation tank. If the pre-oxygenation tank is offline, the slurry will be diverted to the first leach tank, via an internal dart plug distribution system.

The leach circuit will consist of five, mechanically agitated, leach tanks operating in series. This equates to a nominal residence time of 34.4 hrs at a slurry feed rate of 458 m3 /h. Each leach tank will have a live volume of 3,150 m³.

Cyanide, for gold dissolution, will be added to the leach circuit by dedicated cyanide dosing pumps. The primary cyanide dosing point will be the first leach tank, with further addition points located down the leach train. The operating pH of the leach circuit will be maintained above 10.5 to maintain the protective alkalinity of the circuit and prevent the loss of cyanide to gaseous hydrogen cyanide. Protective alkalinity will be maintained by the addition of quicklime to the SAG mill feed conveyor. Because of the slow response time between the lime addition point and the leach tanks a secondary means of emergency pH control is provided in the form of caustic addition points into each leach tank. Note that this will be used in emergencies only and will need to be monitored to limit unnecessary or accidental caustic consumption.

Carbon Absorption Circuit.
The slurry from the leach circuit will report to the Pumpcell® CIP plant feed launder. The feed launder will distribute the slurry to the first tank, within the carousel adsorption sequence.

Elution and Carbon Regeneration.
The Elution circuit will consist of separate acid wash and elution columns. A cold acid wash will be utilized. Following acid wash, gold will be eluted from the carbon, utilizing a pressure Zadra elution process. With the CIP circuit operating on a daily cycle, one elution will be completed every day. The elution circuit will be designed to complete one strip per 20-hour period. At a carbon gold loading of 2,659 g/t the required daily carbon movement equates to 5 t.

Acid Wash.
The acid wash column fill sequence will be initiated by taking the first carbon tank offline and pumping its entire content to the Loaded Carbon Screen. Carbon will gravitate from the Loaded Carbon Recovery Screen directly into the Acid Wash Column while the underflow slurry from this screen will return by gravity back into the carousel feed launder. Once the Acid Wash Column is filled to the required level, the carbon fill sequence will be stopped.

Elution.
The elution sequence will commence with the injection of make-up raw water into the Strip Solution Tank, along with the simultaneous injection of cyanide and caustic solution. A set amount of cyanide and sodium hydroxide (caustic) will be added to achieve a 1% w/w NaOH and 0.2% w/w NaCN strip solution. Both reagent additions will be automatically stopped once the prescribed volume has been added. The pre–heating period will then commence. During this period, the strip solution will be circulated through the first heat exchanger to pre-heat it to 95°C. Upon completion of pre- heating, the elution sequence will commence and gold will be stripped from the carbon. During this stripping time barren eluate, from the strip solution tank, will be pumped, through the heat recovery heat exchanger, picking up esidual heat from the eluate exiting the elution column.

Carbon Regeneration.
After elution, the carbon will be hydraulically transferred from the elution column to the carbon regeneration circuit by pressurizing the column with transfer water. The carbon and transfer water will be directed to the carbon dewatering screen, allowing excess water to be removed prior to the carbon discharging into the carbon regeneration kiln feed hopper. Dewatering screen undersize will gravitate to the carbon safety screen.

Carbon will be withdrawn from the Kiln Feed Hopper, via the Kiln Screw Feeder, and discharged directly to the carbon regeneration kiln, at a rate of 250 kg/h. Within the diesel fired, horizontal rotary kiln, the carbon will be heated to 700°C, to remove volatile organic foulants from the carbon surface, thereby restoring the carbon activity.

Electrowinning and Gold Room.
Soluble gold and silver recovery, from the pregnant eluate, will be achieved by electrowinning onto stainless steel cathodes. The electrowinning circuit will consist of two parallel electrowinning cells, each containing 12 cathodes and 13 anodes. A dedicated rectifier, per electrowinning cell, will supply the necessary current, to electroplate the dissolved gold onto the cathode.

The gold bearing filter cake will be thermally dried in an electric drying oven. Dried filter cake will be mixed with a prescribed flux mixture (silica, nitre and borax), prior to being charged into the diesel fired gold furnace. The fluxes added react with base metal oxides to form a slag, whilst the gold and silver remains as a molten metal. The molten metal will be poured into moulds, to form doré ingots, which will be cleaned, assayed, stamped and stored in a secure vault ready for dispatch. The slag produced will periodically be returned to the grinding circuit, via the SAG mill.

The gold room and electrowinning area will be serviced by a gold trap and dedicated gold room area sump pump. Any spillage within this area will be pump.

Auxiliary equipment for the Electrowinning and Gold Room circuit will include:
• Furnace bag house, extraction fan and stack.
• Electrowinning cell fume hood.
• High pressure cathode cleaner.
• Smelting furnace cascade trolley and slag cart.
• Doré moulds and doré wash table.
• Flux bin, platform scale, flux mixing table.
• Doré balance.
• Doré safe and strongroom.