Name and Location
Banfora gold project, Burkina Faso.

Client
Gryphon Minerals.

Project Description
Optimisation studies on the Banfora gold project have demonstrated robust economics across a range of heap-leach and carbon-in-leach (CIL) development options, highlighting low capital and operating costs.

While the base case two-million-tonne-a-year CIL operation presented in the bankable feasibility study released in January 2013 is still considered the optimal option under stronger market prices, the optimisation studies results indicate that:
• heap-leach options are more robust at lower gold prices;
• the larger two-million-tonne-a-year CIL option converts more of the resource into pit inventory, owing to the higher process recoveries for the primary material; and
• the two-million-tonne-a-year heap-leach option performs better across the range of gold prices, owing to the lower capital and operating costs.

The results highlight a preferred low-cost startup heap-leach operation, which will generate strong returns in a lower gold price environment and is highly leveraged to any gold price increases. The process design is based on proven, conventional heap-leach technology with an initial production capacity of two-million tonnes a year, which can be upscaled at a later date.

The process route comprises two-stage crushing, followed by cement agglomeration and overland conveying to heap-leach pads. The pad area includes full plastic lining, conveyor stacking in two 10 m lifts and drip irrigation with dilute cyanide solution. Pregnant solution is treated at a dedicated adsorption/desorption/recovery plant, using elution, electrowinning and smelting to produce gold doré.

The mining operation proposes the engagement of a mining contractor using conventional truck-and-shovel openpit methods.

The heap-leach facility will process an esti-mated 17-million tonnes of plant feed over an 8.7-year mine life, averaging 71 000 oz/y, at an average head grade of 1.44 g/t gold. The waste-to-plant feed strip will be 2.6, giving an average yearly total material movement of about 7.1-million tonnes.

Plant feed material will be trucked from the three satellite deposits of Samavogo, Fourkoura and Stinger to the processing facility adjacent to the Nogbele deposit. The deposit contributes about 68% of the total pit inventory, which comprises 79% oxide and transitional material, with an average vertical depth of 40 m of oxide material.

Value
Capital costs to develop a two-million-tonne-a-year heap-leach operation and associated infrastructure are estimated at $79-million.

Duration
Not stated.

Latest Developments
Gryphon Minerals is finalising a bankable feasibility study on its preferred heap-leach option, based on strong project economics, the results of which are expected in the June quarter.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Too early to state.

Contact Details for Project Information
Gryphon Minerals, tel +61 8 9287 4333, fax +61 8 9287 4334 or email admin@gryphonminerals.com.au.