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.

Open pit mining at the Çöpler project is carried out by a mining contractor and managed by Anagold. The mining method is a conventional open pit method with drill and blast and utilising excavators and trucks operating on bench heights of 5 m. The mining contractor provides operators, line supervisors, equipment, and ancillary facilities required for the mining operation. SSR Mining provides management, technical, mine planning, engineering, and grade control functions for the operation.

Crushing and Ore Handling
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.

ROM ore is reclaimed from the bin by the sizer apron feeder, which discharges material into the mineral sizer. The sizer is a tooth roll unit which crushes the ore from a feed top size of 500 mm to a nominal top size of 250 mm. Discharge from the sizer drops down a chute onto the sizer discharge conveyor.

The sizer teeth are configured in a manner to direct oversize rocks to one end where they pass through a spring-loaded oversize rejection gate and fall to a reject bunker. The crushed product is carried by the sizer product conveyor to the SAG mill feed conveyor. The SAG mill feed conveyor has a belt scale to monitor the ore flow to the SAG mill and this information is used to control the sizer apron feeder speed.

Grinding
The SAG milling stage consists of a high aspect SAG mill with water cannon pebble recycle. The SAG mill grinds the crushed ore to produce a discharge particle size distribution P80 of approximately 1,400 µm.

Large ore particles are retained in the SAG mill by the internal SAG discharge grate. Particles too large for ball milling are retained as oversize on the SAG mill trommel screen and this oversize is washed by trommel sprays. The trommel screen oversize is captured by a scoop on the trommel then dropped into a static central return tube from where it is projected back into the SAG mill using a high-pressure water cannon. Slurry that passes through the trommel screen discharges into the grinding cyclone feed pump box where it mixes with the ball mill discharge slurry and density control water.

Slurry collected in the grinding cyclone feed pump box from the SAG mill and ball mill is fed to the grinding cyclone cluster. The cyclones produce an overflow product with a P80 of 100 µm, which is screened to remove any trash (organic material, etc.) by the grinding trash screen. Coarse particles report to cyclone underflow, which is returned to the ball mill for further size reduction until it is fine enough to report to cyclone overflow and leave the circuit.

The slurry product from the grinding circuit, trash screen undersize, is currently thickened in a high-rate thickener and excess water reports to the thickener overflow for immediate re-use within the grinding circuit. The thickened slurry discharging from the thickener underflow is pumped to the grinding thickener underflow storage tanks.

To provide for the flotation circuit, a portion of the trash screen undersize, dependent on POX autoclave sulfide sulfur requirements, will be diverted to the flotation circuit where the remaining slurry continues to the thickener.

Sulfide Plant
The sulfide plant commenced commissioning in the fourth quarter of 2018. The basic flow sheet comprises:
- Crushing and ore handling;
- Grinding;
- Acidulation;
- Pressure oxidation;
- Iron/arsenic precipitation;
- Counter Current Decantation (CCD);
- Gold leach, carbon adsorption, and detoxification;
- Carbon desorption and refining;
- Neutralization and tailings/
- Tailing storage facility (“TSF”).

The sulfide plant performance from the fourth quarter of 2018 up to the first quarter of 2020, including commissioning and ramp-up, has achieved greater-than-design throughputs and approaches design gold recovery for the ore types processed.

The incorporation of a new flotation circuit in the existing sulfide plant to upgrade SS to fully utilize POX autoclave oxidation capacity is under design and construction. This addition to the sulfide plant is incorporated between grinding and acidulation by ta ........