Orezone Gold has announced highlights from a recently completed independent feasibility study of its 100% owned Bomboré gold project in Burkina Faso, West Africa. The study envisions a shallow, open-pit mining operation with a processing circuit that combines heap leaching and carbon-in-leach, with no grinding required to process the soft and mostly free-digging oxidized ores.
The 11-year Bomboré mine plan consists of a large number of shallow pits of varying tonnage. A fleet of 32-mt haul trucks, such as Volvo or Scania rear-dump units, will be used to provide mining versatility. Processing throughput is planned at 5.5 million mt/y.
Gold production during the first eight years of production is expected to average 135,000 oz/y. Life-of-mine production is estimated at 1.275 million oz.
The mine plan is based on a mineral reserve using a $1,100/oz gold price. Ore will grade 0.88 g/mt gold over the first eight years of production at a strip ratio of 1:1. Lower-grade stockpiles will be processed in the final three years. The feasibility study only considers measured and indicated near-surface saprolite (oxide) and transitional (semi-oxidized) resources to an average depth of 45 m.
The ore is composed almost equally of plus-212 µm and minus-212 µm material. Plus-212 µm material will be processed via heap leaching, and minus-212 µm material will be processed through carbon-in-leach circuits. Gold will be recovered in a standard carbon desorption plant, followed by electrowinning and smelting to produce gold doré bars.
Metallurgical testing indicates that the overall recovery will be 87% for combined heap leach and carbon-in-leach processing.
A second phase of project development could expand the carbon-in-leach circuit with the addition of grinding to process a well-defined sulphide resource of 73 million mt at a grade of 1.1 g/mt for 2.6 million oz of contained gold.