Canadian junior Roxgold Inc. has announced the results of an NI 43-101 compliant feasibility study of the 55 Zone on its Yaramoko exploration permit in southwest Burkina Faso. The study envisions an underground mine, producing 99,500 oz/y of gold over an initial mine life of 7.4 years. Average all-in sustaining production costs are estimated at $590/oz. Pre-production capital is estimated at $106.5 million.
Probable mineral reserves at the high-grade 55 Zone stand at just under 2 million mt, grading 11.8 g/mt gold and containing 759,000 oz of gold.
Roxgold President and CEO John Dorward said, “We will continue to advance the project through financing and permitting over the coming months, with the aim of commencing underground development in the fourth quarter of this year.”
Under Burkina Faso’s mining code, the government of Burkina Faso is entitled to a 10% interest in the Yaramoko project upon formal award of an exploitation permit.
The 55 Zone will be developed through two spiral declines in the upper reaches of the mine, from the 5270 level down to the 5072 level. From the 5270 level, a single decline will be driven down to the 4884 level, a depth of 430 vertical m below surface.
Mining will be conducted using longhole retreat mining on closely spaced sublevels, with cemented-rock backfill used to eliminate non-recoverable pillars, maximizing mining recovery to 96%. The mine plan assumes contractor mining, with engineering and grade control provided by Roxgold.
Development of the box cut for the underground mine is scheduled to begin in the fourth quarter of 2014. Owner mining is assumed after approximately five years of operation.
The mine plan is based on a 4.9-g/mt cut-off at a minimum width of 1.6 m. A 750-mt/d extraction rate is planned. The typical stope has a 25-m strike length, a vertical height of 34 m, and full-vein width. Twenty-four levels of lateral development designed to open up multiple working faces and allow operating flexibility are incorporated in the mine plan.
The processing facility will be sized for 750 mt/d throughput and will include single-stage jaw crushing, SAG milling, gravity recovery, leaching and adsorption circuits, gold recovery, and thickening. Recoveries are assumed to average 96.9%.
Roxgold also recently announced an exceptionally high-grade intercept from its current diamond drilling program at the Yaramoko project’s Bagassi South zone, 1.8 km south of the 55 Zone. The intercept assayed 226.76 g/mt gold over 2.7 m true width, including 442.00 g/mt gold over 1.4 m true width.
