The Sissingué deposit is situated in the Syama Boundiali Greenstone Belt. The geology of the belt has similarities to the better explored Ashanti Belt in neighbouring Ghana, where Birimian volcanoclastics dominate over competent volcanics, with the development of inner belt basins filled with Tarkwaian epiclastics. In the Bagoe River region near Tengrela, the terrain is comprised of undifferentiated granitoids, flysch sediments, intermediate volcanic and small occurrences of mafic intrusive and molasse sediments.

The Sissingué deposit is defined by a 4 km long and up to 1.5 km wide gold-in-soil anomaly situated 5 – 6 km west of the Syama-Boundiali Greenstone Belt (Figure 1.3.2). Rocks encountered in outcrops and drilling comprise predominantly north-north east striking, steeply west dipping and isoclinally folded sediments (sandstones, mudstones and subordinate conglomerates) of the Birimian Supergroup, interpreted as units of turbiditic flows. These sediments are cross cut by a swarm of narrow porphyritic dykes (sub-metre to several metres thick) which trend obliquely to the sedimentary package north-west with sub vertical or steep to moderate dips towards the northeast. Some minor dykes appear to have exploited weak zones parallel to sedimentary bedding.

Mineralisation was domained by its host lithology for modelling (granite, porphyritic dykes and sediments). Within the dyke domain mineralised sediments in the alteration halo of the dykes were included in the dyke domain to maintain a minimum width of the wireframes and to maintain continuity along strike. Where geological contacts were not clearly controlling the distribution of mineralisation, a grade cut-off of 0.3 g/t Au was used to construct Mineral Resource boundaries and to provide overall geometry to mineralised zones. A minimum of 4 m width was used for the wireframes and samples of grades below the nominal cut-off of 0.3 g/t Au were included where the wireframe would otherwise be less than 4 m wide. Analysis of the global grade distribution shows that there is a natural change in grade population at around 0.3 g/t Au.

The mining method planned for the operation is conventional open pit excavation with ex-pit waste dumping. The pit will be accessed by a 20 m wide haul road incorporating a 10 percent gradient and two lane ramps. At the pit floor the final benches will be accessed using single lane ramps.

The ramp exit points for each design were placed on the east to provide the shortest hauls to the ROM pad and waste dump. The waste rock dump was located to the east of the pit and adjacent to the processing plant.

The proposed process plant design for the Sissingué Gold Project is based on a robust metallurgical flowsheet designed for optimum recovery with minimum operating costs. The flowsheet is constructed from unit operations that are well proven in industry.

Perseus has advised that ores will be mined so that predominantly oxide / transitional ore will be processed in two phases; during the first year and then again for a five month period in Year 3. Some blending with primary ores will be required in the final two years. Oxide ore will be processed at a rate of up to 1.2 Mt/y using a two stage crushing and single stage SAG mill circuit. Primary ore will be processed at a rate of 1.0 Mt/y using a three stage crushing and ball mill circuit, where the SAG mill has been re-configured to operate as a ball mill.

The treatment plant design incorporates the following unit process operations:
• Initially two stage crushing of oxide ore with open circuit primary crushing and closed circuit secondary crushing to produce a crushed product size of 100% passing (P100) 50 mm.
• Thereafter three stage crushing of primary ores with open circuit primary crushing and closed circuit secondary and tertiary crushing to produce a crushed product size of 100% passing (P100) 14 mm.
• A crushed ore surge bin with a nominal capacity of 100 t. Surge bin overflow will be conveyed to a dead stockpile. Ore from the dead stockpile will be reclaimed by front end loader (FEL) to feed the mill during periods when the crushing circuit is off-line.
• Initial single stage SAG milling of oxide ore in closed circuit with hydrocyclones to produce a P80 grind size of 106 µm.
• Thereafter, ball milling of primary ore in closed circuit with hydrocyclones to produce a P80 grind size of 106 µm.
• Gravity concentration and removal of coarse gold from the milling circuit recirculating load and treatment of gravity concentrate by intensive cyanidation and electrowinning to recover gold to doré.
• Pre-leach thickener to increase the slurry density to the carbon in leach (CIL) circuit to minimise CIL tankage, improve slurry mixing characteristics and reduce overall reagent consumption.
• Initial leach / CIL circuit for oxide ore incorporating one leach tank and six CIL tanks containing carbon for gold adsorption.
• Thereafter pre-oxidation / CIL circuit incorporating one pre-oxidation tank with oxygen addition to reduce leach oxygen requirements and cyanide consumption and six CIL tanks containing carbon for gold adsorption.
• Four tonne pressure Zadra elution circuit, electrowinning and gold smelting to recover gold from the loaded carbon to produce doré.
• Tailings pumping to the tailings storage facility (TSF).