The Bissa and Bouly gold deposits all occur within an approximate 90 km NW-SE zone, comprising Birimian volcano-sedimentary rocks of the Boromo greenstone belt. The belt consists of mafic volcanic rock, minor felsic volcanic rock and extensive sedimentary units, intruded by Eburnean granitoids, all of which have undergone incipient to low greenschist facies metamorphism (Huot and Sattran, 1987). The Bissa Hill, SW, IOSE, Z51, Z52 and Boken Zandkom deposits all fall within an approximate 9km NE-SW oriented corridor (“the Bissa-Zandkom corridor”) in the northeastern portion of the Boromo greenstone belt. This corridor comprises a series of interbedded argillaceousarenaceous sediments, alongside sequences of mafic volcanic rock. The thick metasedimentary sequence represents the principal host to mineralisation. Structurally, the lithological assemblage at Bissa-Zandkom appears to be tightly folded, with a broad NE to ENE trend, and is offset by several large-scale faults that trend NW-SE. At least two phases of deformation can be identified at the mine-scale, including an earlier D1 and later D2, resulting in a re-folded fold sequence. Bouly, which lies to the southeast of Bissa, appears to represent a large, low grade gold-copper porphyry. The Bouly deposit, approximately 9 km east of the Bissa-Zandkom corridor, is hosted by shear zones within metamorphosed metavolcanics, diorites and porphyritic diorites. The volcanosedimentary sequence is well foliated, with a NE-SW strik ........

The operation envisages open pit mining, utilising drill & blast with a truck and shovel approach to ore and waste haulage. Mining – Bissa Mining operations at Bissa are focused on a number of different open pits. Bissa gold mine operates a typical modern open pit operation with drilling and blasting followed by load and haul allowing for selective mining of the ore. The material lithologies are divided into four main categories: Laterite, Saprolite, Transition, and Fresh. Fleet capacity is sufficient, with only rebuilding and some replacement capital necessary during the LoM. There are currently 39 trucks with a payload of 100 t that are used for production from the open pits. Assumed cycle times average 24 minutes. The mine has several significant opportunities to extend the LoM but this will depend on the exploration program and the gold price. The ramps have been designed at a gradient of 10% at 23 m width. The mining benches are between 8 m and 16 m high and are loaded out in 4 m fletches. Mining – Bouly The Bouly operation extracts material from multiple open pits. The ore is hauled to the heap leach pads, while the waste is hauled to the waste dumps. Production is undertaken through conventional drilling, blasting, loading and hauling processes. There are currently 16 CAT 777 90 t haul trucks at Bouly which are shared with the Bissa operation. There are two PC2000s and two CAT6015s at Bouly, and CAT 993 front-end loaders (“FEL”) are used on the stockpiles. ........

BISSA
Crushing
RoM ore is screened at 800 mm on a stationary grizzly, with oversized broken using a rockbreaker. The primary crusher is a Metso C140 jaw crusher operating with a nominal CSS of 170 mm. The crusher is preceded by a 150 mm aperture vibrating grizzly.

Grinding
The first grinding stage consists of a 8.5 x 4.35 m SAG mill (6000 kW) that is closed with a 10 mm slotted aperture screen. A Pebble Crusher was installed in 2014 crushing a recycle rate of approximately 12%. Screen undersize reports to the 6.1 x 9.05 m (6000 kW) ball mill, which operates in closed circuit with a bank of 380 mm cyclones. After screening for trash removal, cyclone overflow reports to the CIL circuit.

BOULY
Ore is crushed to a target 100% -45 mm 80% -21 mm using two parallel trains, each train consisting of a single Metso C140 jaw crusher, preceded by a vibrating grizzly with a nominal 102 mm aperture, followed by a single Metso HP800 cone crusher preceded by a double deck screen with apertures 80 mm and 25 mm.

The Bouly process plant treats low grade non-refractory oxidised saprolite and transitional saprock hosted gold ore by heap leaching, with gold doré produced at the Bissa plant. The plant commenced production in 2016 with a design production rate of 7.5 Mtpa of ore.

Heap Leaching
Cement is added from storage soils to the crushed ore at a typical rate of 10 kg/t, and the ore is then agglomerated using a 4.6 m diameter, 14.0 m long agglomeration drum, to which is added barren leach solution at a nominal rate of 115 L/t of ore. The ore is then transported to the leach pad using a series of overland conveyors, feeding onto mobile grasshopper conveyors and finally to a radial stacker. The lift height is 10 – 12 m and the pads are designed to ultimately consist of four lifts with potential to stack up to six lifts being investigated. An interlift liner and drainage are installed for each lift. Leach solution is applied using wobbler sprinklers. The nominal leach cycle is 150 ........