Perseus Mining announces maiden ore reserve in Cote d’Ivoire

Perseus Mining announces maiden ore reserve in Cote d’Ivoire

Perseus Mining Limited has announced a maiden Ore Reserve of 2.2Mt at 3.58g/t for 259 koz for the initial stages of mining of the CMA orebody by underground methods beneath the existing CMA open pit, at its Yaouré Gold Mine in Côte d’Ivoire.

A PFS on the drilled-out portion of the CMA deposit at Yaouré has been completed which has proven the economic and technical viability of underground mining immediately beneath the existing open pit, adding additional value to the Yaouré Gold Mine.

More widely spaced drilling below the underground Ore Reserve has shown that mineralisation extends deeper allowing an extension to Inferred Mineral Resources at depth. The total Mineral Resource for CMA underground now exceeds 1 Moz.

“Having attained the goal of producing gold at a rate of 500,000oz per year across our three gold mines, we are now working to maintain, and where possible, exceed that level of production over the next decade and beyond.

Perseus’s Managing Director and CEO Jeff Quartermaine

“These latest drill results from Yaouré give us further confidence in the high-grade gold contained beneath the CMA open pit and the results of a Pre-Feasibility Study and maiden Ore Reserve for the first portion of CMA Underground Project are encouraging.

This initial stage of the development will carry the bulk of the development costs of the underground operation, and as further Resources and Reserves are delineated by the drilling programs currently underway on the site, the average AISC should be reduced turning the CMA underground into a very profitable extension of the already profitable open pit operation,” commented Perseus’s Managing Director and CEO Jeff Quartermaine.


  • The chosen method for the Open Pit Ore Reserves is conventional open pit mining utilising hydraulic excavators and trucks. A mining bench height of 10 metres is used, with loading on 2.5 metres flitches to minimise ore loss and dilution.
  • The economic pit shell was defined using Whittle pit optimisation software (“Whittle”) with inputs such as geotechnical parameters, ore loss and dilution, metallurgical recoveries, operating costs, and gold price.
  • The pit slope design assumptions were based on a geotechnical study by Pitt & Sherry Consultants. Inter-ramp pit slopes are 40 to 60 degrees varied by material weathering level and wall sector. Inter-ramp slopes are excluding ramp but including berms spaced at between 10 and 20 metres vertically and berm widths of 5 to 7 metres.
  • Pit ramps have been designed for a 100-tonne payload truck fleet and are set at 24 metres (dual lane) to 16 metres (single lane).
  • Minimum mining width of 40 metres was generally applied to the pit cutback designs.

The stockpiles that existed on 30 June 2022 will be all fed to the processing plant over the mine life based on the blending strategy and associated re-handling costs for all material are allowed for.
The Mineral Resources were classified as Measured, Indicated and Inferred. The Ore Reserves, based only on the Measured and Indicated Resources, have been classified as Proved and Probable Ore Reserves, respectively.

“We look forward to progressing Perseus’s first underground mining development which is also likely to be the first large scale underground mine operating in Côte d’Ivoire.” concluded Quartermaine.

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