The Öksüt Project is a high-sulphidation epithermal gold deposit within the Central Anatolian Volcanic Province, part of the Tethyan Metallogenic Belt. The belt extends from southeastern Europe across Turkey, the Caucasus, and on into Pakistan and contains a number of important gold and porphyry copper deposits. Magmatic activity and related ore forming processes are the result of the closure of the Tethyan Ocean in response to the collision between the northmoving Arabian Plate with the Eurasian Plate that began in the late Cretaceous period and continues today.

Öksüt gold mineralization is hosted within the Develidag Volcanic Complex, one of the numerous stratovolcanoes situated along the Central Anatolian Fault Zone (CAFZ). The volcanic complex is composed of Miocene basaltic-andesitic volcanic domes, pyroclastic rocks, and lava flows. Flow- banded Pliocene andesite overlies these sequences and the Öksüt mineralization to the north and east.

There are several gold occurrences in the Öksüt Project area, the most important of which is the Keltepe Deposit. The distribution of the alteration assemblages and the gold grades at the Keltepe Deposit are strongly zoned, with a central massive silica breccia having the highest gold grade. This core is surrounded by quartz-alunite altered volcanic rocks, and as the alteration intensity diminishes outwardly, the gold grade decreases.

The Keltepe Deposit has been oxidized to depth, up to 400 m below the surface. The original copper content of the deposit has been completely leached out of the current resources, however, zones of oxide copper enrichment are found deeper within the deposit, below the planned open pit. An irregular zone of supergene enrichment exists below the oxide zone, with some high grade sulphide copper intersections. It is surmised that the oxidation of the deposit has liberated the gold allowing heap leaching at a relatively coarse crush size.

The nearby Güneytepe Deposit is significantly smaller based on the drilling information collected to the end of 2014 and does not show the more straightforward zonation and continuity of alteration and gold grades as observed on the Keltepe Deposit. Silicification is intense, however, the host rocks are much less porous, and, as a result, oxidation is restricted to the upper 50 m to 75 m of this deposit.

The Öksüt Project is planned as a conventional truck and shovel open pit mine. Material will be drilled and blasted, before being loaded and hauled to the waste dump, crusher, or the various ore stockpiles depending on the most profitable way to process the material. At the Öksüt Project, two pits have been planned to be mined simultaneously, the main Keltepe pit and the small satellite Güneytepe pit.

It is planned to use a mining contractor to do all mining using small excavators and 36 tonne trucks. The use of this equipment among mining contractors is common in Turkey. The mining contractor will provide and maintain all equipment, and will perform drill, blast, load, haul, and road and dump maintenance on a unit cost basis. Centerra will provide oversight of the mining operations, grade control, survey control, mine planning, and other required technical services.

The Keltepe pit will be developed in three cutbacks in order to smooth stripping requirements and mine higher grade material earlier in the mine life. Due to its small size, the Güneytepe pit will be developed in a single cutback. Lower grade material will be stockpiled throughout the Project for processing at the end of the mine life. This allows higher grade material to be processed earlier, increasing the Project net present value (NPV).

Run-of-mine ore will be delivered by 36-tonne haul trucks to the primary crusher. The ore will be dumped on the stationary grizzly installed over the 80-tonne truck dump hopper. Oversize rocks will be handled by a rock breaker. The ore will be withdrawn from the dump hopper via a 2.0 m wide x 4.0 m long grizzly feeder. The grizzly oversize will feed the 1.6 m x 2.0 m jaw crusher that will reduce the rock size to minus 150 mm prior to being conveyed by a 1.4 m wide x 95.5 m long belt conveyor to the secondary crushing circuit, along with the grizzly feeder undersize. A self-cleaning belt magnet will be installed over the conveyor belt feeding the secondary crusher building. A metal detector installed after the belt magnet will identify any remaining piece of metal and the conveyor will be stopped to allow manual removal by an operator.

The product from the primary crushing circuit will feed a 2.4 m wide x 6.1 m long double-deck screen. The screen oversize will feed a 600 kW cone crusher while the screen undersize will report with the cone crusher product and will be transported by a 1.1 m wide x 50.7 m long belt conveyor to a radial stacker after quicklime has been added to the crushing circuit product. A 10,000 t capacity stockpile will be formed by the 1.1 mm wide x 39 m long stacker installation.

Dust collection units will be provided at the crusher discharge and transfer points in both crushing buildings and a dry fog system will be installed at the truck dump. If required, additional dust control measures could be implemented. A compressor will provide compressed air for process and instrumentation applications.

The flowsheet is based on an 11,000 tpd heap leach operation. It includes primary crushing, screening and secondary crushing, heap stacking and cyanide leaching, carbon adsorption, carbon stripping and regeneration, electrowinning, and refining. The concepts and data presented in this section are taken from the Process Flowsheets and Process Design Criteria developed for the Project.

HEAP STACKING
The crushed ore will be trucked from the crushing facility to the HLP. The HLP will be developed in three phases for an ultimate ore capacity of 40 Mt.

HEAP LEACHING
The heap will be irrigated with a diluted cyanide solution recirculated from the gold recovery circuit, via a network of piping covering the surface area under leach. The barren leach solution will be pumped from the barren tank at the ADR plant to the heap. The cyanide concentration will be adjusted and the pH will be controlled so that HCN gas formation is inhibited. The solution will be filte ........