The setting, alteration mineralogy and mineralization characteristics of the mineralization within the Project are somewhat consistent with an intermediate sulfidation epithermal system as defined in Hedenquist et al., (2000). Some deposits with mostly lowsulfidation characteristics with respect to their alteration mineral assemblages have sulfide ore mineral assemblages that represent a sulfidation state between that of highsulfidation and low-sulfidation deposits. Such deposits tend to be more closely spatially associated with intrusions, and Hedenquist et al., (2000) suggest the term ‘intermediate sulfidation’ for these deposits.

Intermediate-style epithermal systems are typically hosted in arc-related andesitic and dacitic rocks. Mineralization is silver- and base metal-rich, and associated with Mncarbonates and barite. Sulfide assemblages in intermediate-style epithermal systems typically comprise tennantite, tetrahedrite, hematite–pyrite–magnetite, pyrite, chalcopyrite, and iron-poor sphalerite. Quartz can be massive or display comb textures. Sericite is common as an alteration mineral, but the adularia, more typical of low sulfidation systems, is rare to absent.

Epithermal gold mineralization at Çöpler occurs within structurally-controlled zones of stockwork and sheeted veins hosted by a Tertiary diorite intrusion and an older metasediment complex, and as contact-type mineralization along the intrusivemetasediment fault contact with the Munzur Formation limestones. The epithermal mineralization may be related to porphyry copper-style mineralization that has been intersected by several of the drill holes.

The Main Zone lies in the west portion of the Project area and occupies a footprint of approximately 750 m north to south by 1,000 m east to west. Typical depths of mineralization range from surface to +200 m in depth. Disseminated quartz-pyrite-arsenopyrite epithermal veinlets are primarily hosted in diorite and metasediments with some marble-hosted mineralization on the eastern margin of the zone. Oxidation has occurred, and oxide mineralization occurs from near surface to depths of approximately 40 m, with the thickest development over ridges and thinning in the intervening valleys.

The Manganese Mine Zone occupies the eastern end of the Çöpler mining area. The zone is approximately 650 m wide from north to south by approximately 650 m in the east to west direction. The pre-mining surface expression of this area consisted predominately of marble. A moderately-sized intrusion of diorite occurs sub-surface. A large proportion of the Manganese Mine Zone mineralization is associated with the contact between this diorite and the surrounding marble. Mineralization ranges from surface to approximately 400 m deep.

Free gold mineralization occurs in the marble with minimal associated sulfides. Disseminated quartz-sulfide mineralization occurs in clay-altered and brecciated diorites as well as locally carbonate-altered diorite. Moderate volumes of massive sulfide pyrite mineralization occur within the Manganese Mine Zone. It appears that “leachable” mineralization is a combination of free gold in marble and supergene oxidized mineralization in both marble and diorite. Leachable oxide mineralization occurs to over 200 m in depth.

The Main Zone East represents the portion of the mineralization lying between the Manganese Mine Zone and Main Zone. The geology in this area is typified by narrow, weakly to moderately-mineralized gossans located at the contact between the basement metasedimentary rocks and the overlying marble. It is postulated that the gossan is sourced from the diorite located in the Manganese Mine Zone and has been emplaced along the metasediment marble contact as the diorite has crystallized.

The Marble Contact Zone occurs in the southeastern portion of the Project area and is associated with a northeast-striking fault contact between marble on the east and metasediments and intrusions on the west. The geology in this area is typified by large ‘plugs’ of gossan and diorite that have formed at the junctions between large-scale faults, where mineralizing fluid flow has been considerable. The width of the Marble Contact Zone is approximately 350 m, and the strike length is 300 m in an east-northeasterly direction. The depth of mineralization ranges from surface to approximately 160 m. Mineralization occurs as both disseminated sulfides in veinlets and massive sulfide along the marble contact. Oxidation has occurred along the northeast structure resulting in greater depths of oxidized mineralization than in the Main Zone.

The West Zone occupies the westernmost portion of the Project area and is located at the contact between the basement metasedimentary rocks and the overlying limestone, where a large-scale northeast-trending fault is located. Mineralization is present within veinlets containing disseminated sulfides, massive sulfide and oxidized gossan. The West Zone has a strike length of approximately 700 m in a northeasterly direction and is approximately 150 m wide. Multiple, narrow, mineralized zones are present sub-parallel to the faulted contact, and occur to a depth of approximately 150 m below surface.

Main Zone West is located in the northwest corner of the Project area at the contact between diorite, marble and the basement metasedimentary units. The mineralization is hosted within narrow gossans located at the contact, and in subparallel veinlets containing disseminated sulfides within the marble and metasedimentary rocks. Main Zone West has a strike length of approximately 750 m and is approximately 75 m wide.

All mining at Çöpler will be undertaken by conventional open pit mining techniques used for hard-rock truck-and-shovel operations. Contractor mining will be retained for the LOM.

The process was designed to treat approximately 6.0 Mtpa of ore by three-stage crushing (primary, secondary and tertiary) to 80% passing 12.5 mm, agglomeration (with lime and water) and heap leaching on a lined heap leach pad with dilute alkaline sodium cyanide solution. Gold is recovered through a carbon-in-column (CIC) system, followed by stripping of metal values from carbon using high temperature, pressure elution process, and electrowinning, retorting and melting of the resulting product to yield a doré (containing gold and silver) suitable for sale. Carbon is regenerated using acid washing and reactivation in a rotary kiln, and the carbon is recycled back to the CIC system. Subsequent to commissioning of the plant, a SART plant has been constructed and commissioned to remove copper from the leaching solution and to regenerate cyanide. The SART process operates intermittently, on an as-needed basis.

Haul trucks from the mine tip ore onto designated stockpile fingers. The ore is withdrawn from stockpiles by front-end loader (FEL) and deposited into the ROM dump hopper. A static grizzly is fitted to the top of the ROM bin to remove coarse oversize (aperture size 500 mm), and a mobile rock breaker is used to break apart large lumps of ore retained on the grizzly.

The SAG milling stage consists of a high aspect SAG mill with water cannon pebble recycle. The SAG mill grinds the crushed ore (by tumbling large ore particles and steel grinding media) to produce a discharge particle size distribution P80 of approximately 1400 µm.

The grinding thickener underflow storage tanks provide process surge and effectively decouple the upstream crushing and grinding circuits from the downstream hydrometallurgical circuit. If the acidulation feed tanks reach their high level limit then ore feed to the grinding circuit will be stopped. If the tanks are approaching their low level limit then the grinding circuit feed rate can be increased to compensate.

The POX feed surge tanks 1 and 2 are a common feed system that services both POX autoclave trains (T1 and T2). The tanks are agitated to mix / blend the incoming slurry, and provide approximately 18 hours of slurry storage to minimize disruptions to the POX circuit. For simplicity, where only POX T1 is discussed in this document it is assumed that both T1 and T2 have identical configurations and controls.

Iron/arsenic precipitation uses limestone slurry addition to the decant thickener underflow slurry to neutralize the free acid and raise the pH to about 2.8, which removes ferric iron and arsenic from solution.

The decant thickener underflow duty pump transfers the thickener underflow slurry to iron/arsenic precipitation tank 1. Limestone is added for pH control, and low pressure air is sparged into the tanks to oxidize ferrous iron that may be present to ferric iron. The ferric ions combine with the residual arsenic, also leached in the POX circuit, and precipitate together as the pH of the solution is raised. Limestone reacting with the free acid generates carbon dioxide gas and gypsum.

Counter current decantation washes the iron/arsenic stage discharge slurry with process water using two stages of thickeners operating in counter current mode. The remaining soluble metals in solution exiting the iron/arsenic precipitation circuit are washed from the slurry and report to CCD1 overflow. The slurry discharging from CCD2 underflow has the soluble metals washed from the slurry to sufficiently low levels to feed into the cyanide leach circuit.

The copper recovery circuit which had been included in the scope of the project in the FS has been removed from the flowsheet. Space for copper recovery equipment has been reserved in the plant layout for future inclusion if required. The CCD1 overflow solution containing a majority of the soluble metals leached in the POX circuit is now sent to the neutralization circuit for precipitation by lime neutralization.

The cyanide leach circuit consists of one pre-leach tank and two leach tanks. Slurry is received in the pre-leach tank from the duty CCD thickener 2 underflow pump. The pre-leach tank has a residence time of 10 minutes and is used to raise the pH of the slurry to between pH 10 and 11 prior to the slurry entering the leach tanks where cyanide is added for gold leaching.

The carbon desorption method selected is a split AARL with cold cyanide strip for copper. The elution column is a 6 t column and is designed to handle the stripping of three carbon batches per day. Loaded carbon enters the elution column via the loaded carbon screen.