Primary gold deposits in Burkina Faso occur within the Paleoproterozoic Birimian belt. Mineralization was synchronous with regional metamorphism and deformation. Gold deposits found within the Birimian greenstone belts of the West African shield are typically late orogenic hydrothermal deposits that exhibit a strong relationship with regional arrays of major shear zones. The gold mineralization is typically associated with an organized network of quartz veins containing subordinate amounts of carbonate, tourmaline, sulphides, and native gold. In these deposits, the gold is typically free milling. Alternatively, gold mineralization can also be associated with disseminated sulphides in strongly deformed alteration zones. In the alteration zones, gold may be free milling, but also refractory.

Gold mineralization is related to regional arrays of alteration and deformation zones, commonly located at major lithological discontinuities. The local controls on the distribution of the gold mineralization are structural and lithological.

In Burkina Faso, the weathering profile is deep and typically results in extensive surface oxidation of bedrock to a depth reaching more than 100 metres locally. In such areas, gold deposits typically comprise a surface oxide zone, an intermediate transition zone, and a deeper fresh rock zone. Gold is typically free milling in the oxide zone.

The gold mineralization found at the 55 Zone and Bagassi South Zone deposits i ........

Mining operations at Yaramoko are comprised of the 55 Zone underground mine, which was commissioned in 2016, and Bagassi South underground mine, which was commissioned in 2019.

Longitudinal longhole stoping with delayed cemented rockfill is the primary mining method adopted for both underground mines. Other than sill pillar stopes, up holes are drilled to breakthrough and surveyed to ensure drilling accuracy prior to production blasting. Sill pillar stopes are drilled as blind up hole stopes as these are the final level to be mined in a panel of four or three for 55 Zone and Bagassi South respectively. A longitudinal stope mining sequence, along strike from vein extremities retreating to a central access in an east and west direction.

Each stope is mined in this fashion over a 25 m strike length for 55 zone and 10 m strike length for Bagassi South.

Blast holes generally consist of parallel up holes utilizing a dice five or zipper drilling pattern due to the narrow nature of the orebody. Holes range from 12 m to 17 m in length, with some drillholes fanned out where vein widths exceed 5.0 m. Drill factors average 2.5 t to 3.5 t per drill meter, common factor for narrow vein ore bodies. Blast holes are loaded with ammonium nitrate fuel oil (ANFO) and low-density ANFO for perimeter control to a powder factor ranging from 1.00 to 1.50 kg per tonne for the initial void firings and 0.50 to 1.00 kg/t for ring firings. Any wet holes are charged with ........

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