The Yaouré Deposit is a structurally controlled, greenstone hosted gold deposit similar in nature to many exploited elsewhere in the Birimian terranes of West Africa.

Gold mineralisation is accompanied by traces of molybdenum, tungsten, antimony, bismuth and tellurium indicating that the mineralisation may have affinities with the reduced intrusion-related gold systems (IRGS). The predominance of structural controls and association with carbonatisation, sericitisation and silicification, however, are characteristics that more clearly point to its classification as an orogenic, mesothermal gold deposit.

The Yaouré gold deposits lie within the eastern half of the informally named Bouflé greenstone belt in central Côte d’Ivoire. The belt is a NNE-trending assemblage of Palaeoproterozoic volcanic, sedimentary and intrusive rocks of the Birimian Supergroup.

Rock types in the Yaouré district are, for the most part, mafic volcanic rocks with minor chert, turbiditic metasedimentary rocks and a fluvio-deltaic formation. The volcano-sedimentary rocks were intruded by tonalite-trondhjemite-granodiorite (TTG) type plutonic rocks and undifferentiated granitoids. Mafic to ultramafic complexes are also found in the Yaouré district.

The entire Birimian rock suite has been metamorphosed to lower greenschist facies.

At Yaouré, structurally controlled gold mineralisation is hosted mainly by Palaeoproterozoic Birimian basaltic rocks. Relatively minor proportions of the Mineral Resource are hosted by a granodiorite intrusion and lesser feldspar, quartz-feldspar and hornblende porphyry dykes.

Gold mineralisation at Yaouré has been subdivided into two main zones: the CMA Zone and the Yaouré Zone. The CMA zone is a relatively continuous 20-45 m thick fault zone featuring quartz-carbonate (dominantly ankerite) veining and disseminated pyrite in albite-carbonate altered wall rocks. It strikes approximately north-south, dips at 30 degrees to the east, extends along 1,200 metres strike and its down-dip continuity has been tested for in excess of 450 m.

The Yaouré Zone comprises a system of structures in a 300 m wide zone, 200 m below the CMA Zone beneath the Yaouré Central Pit. Gold mineralisation is hosted by a series of brittle- ductile structures divided for convenience into ‘Y’ and ‘S’ types. The ‘Y’ fault zones, parallel to CMA, consist of Y1, Y2 and Y3 - shallow easterly dipping reverse faults with associated albite, carbonate and quartz veins in variably altered host rocks with disseminated pyrite. The ‘S’ type structures comprise sub-vertical faults filled with quartz-tourmaline veins. The ‘S’ type structures are oriented west-northwest, east- south-east and north-east, south-west.

Numerous, less well developed mineralised structures also occur in the deposit. The majority strike approximately east-west and dip sub- vertically and are best developed in the granodiorite stock where, in places, they combine with less common flat-lying veins to form a stock work. Gold mineralisation also occurs along granodiorite and porphyry contacts and along zones of competency contrast such as the contacts between massive and pillowed basalts.

Gold occurs within quartz, quartz-carbonate and quartz-tourmaline veins and in adjacent altered wall rocks, typically associated with disseminated pyrite. Other than for very fine particles that may be occluded by silicates or pyrite, the gold is “free milling”, i.e. cyanide soluble.

Gold mineralisation is accompanied by very minor amounts of arsenopyrite and molybdenite.

The selected mining method is conventional open pit mining utilising hydraulic excavators and standard off-highway rear dump trucks with mining undertaken by a contractor.

In ore, mining bench heights are 5 m with 2.5 m flitches for selective mining to minimise ore loss and waste rock dilution. Waste blocks adjacent to ore will be mined on 5 m benches, while bulk waste more distant from the ore zone will be mined on 10 m benches.

The proposed mining operation will use a selective mining method to minimise ore loss and waste rock dilution. The total movement mining rate averages approximately 26.5 Mt/year for the life of mine to deliver ore feed to support the target processing rate of 3.3 Mt/year. The operation is planned to be operated by a mining contractor to strip free dig material such as topsoil, clays and highly weathered rock near surface, as well as remove backfill in the CMA pit. Fresh rock, which is the dominant rock type, will require significant drilling and blasting, and will form the main material mined by the mining contractor.

To balance waste stripping and ore grades the pits are designed to mine to the ultimate boundary limit using cutbacks. Access to the pits will be by 24 m wide haul roads and ramps incorporating a 10 percent gradient with windrow and drain. Single lane ramps will be used as required especially towards the end of pit life to maximise ore recovery and minimise waste mining. Ore and waste will be hauled to surface with or dumped on stockpiles at the ROM pad and waste dumped to waste disposal dump.

Ore and waste rock will be drilled and blasted prior to excavation. The mine will undertake conventional drilling and blasting activities with pre-splitting in key areas of transition and fresh rock to assure stable wall conditions.

Reverse circulation (RC) drilling will be completed for grade control with samples taken on 2m composites, with the assays used to define the ore boundaries.

Loading operations will be performed by hydraulic excavator mining bulk waste in 10 m benches and waste and ore in 5 m benches. Hydraulic excavators and off-highway rear dump trucks will be appropriately matched by the mining contractor. Smaller excavator equipment will be used for ore mining operations.

The mined material will be hauled to the designated destination being either the ore stockpile, the crusher feed bin (direct dump) or waste dumps. The operation will be supported by front-end loaders for ore stockpile rehandle.

Waste rock will be placed in an ex-pit waste rock dump within the mining lease. Backfilling of the open pits is not anticipated giving the continuing mineral potential of the region.

Circuit ROM ore will be drawn from the ROM bin at a controlled rate by an apron feeder and discharged onto a vibrating grizzly. The grizzly oversize will report to the jaw crusher for primary crushing. The jaw crusher product together with grizzly undersize will report to the primary crusher discharge conveyor feeding directly to the coarse ore stockpile.

Ore will be withdrawn from the coarse ore stockpile and fed via the mill feed conveyor to the SAG mill. Lime and SAG mill grinding media will be added to the mill feed conveyor as required.

The grinding circuit will consist of a SAG mill in open circuit, a pebble crusher and a ball mill in closed circuit with hydrocyclones.

The SAG mill will discharge via a pebble dewatering screen, and oversize consisting of pebbles and worn steel grinding media, will discharge onto the pebble transfer conveyor. Worn media will be removed by a magnet and pebbles will be crushed in the pebble crusher and will report back to the SAG mill conveyor. The screen undersize will gravitate to the mill discharge hopper and will be pumped to the hydrocyclone cluster for size classification.

The cyclone underflow (coarse material) will report to the ball mill feed chute for further grinding. The cyclone overflow (product size material) will gravitate to the trash screens prior to leaching.

Plant Capacity: 3.3Mtpa fresh, 3.8Mtpa oxide.
Recovery: 90%.

The treatment plant design incorporates the following unit process operations:
- Primary crushing with a single toggle jaw crusher to produce a coarse crushed product;
- A live stockpile from which ore will be reclaimed to feed the milling circuit;
- A SABC milling circuit comprising a SAG mill in closed circuit with a pebble crusher and a ball mill in closed circuit with hydrocyclones to produce an 80% passing 75 micron grind size;
- Gravity concentration and removal of coarse gold from the milling circuit recirculating load and treatment of gravity concentrate by intensive cyanidation and electrowinning to recover gold to doré;
- A leach and carbon in leach (CIL) circuit of one leach stage followed by six stages of leaching with carbon present for gold adsorption, providing a total of 29 hours leach time at the design leach feed density;
- A split AARL elution circuit treating ........