The Kisladag deposit is hosted by a suite of subvolcanic monzonite porphyry intrusions that are subdivided into Intrusions #1, #2, #2A, and #3. Intrusion #1 is the oldest, and generally best mineralized phase. It forms the core of the system, and is cut by the younger porphyritic intrusions. It is an E-W oriented elongate elliptical body in map view (~1,300 m x ~500 m), and in the subsurface has a sill like form intruding along the contact of the basement and volcanic package (Figure 8-1). At depth the main body extends beyond the current limit of drilling (~1,000 m). Contacts between Intrusion #1 and the surrounding volcanic rocks are generally obscured by alteration. Contacts with younger intrusions, particularly Intrusion #3, are better preserved. Intrusion #1 has a K feldspardominant groundmass with plagioclase phenocrysts (up to 30% of the rock by volume), occurring as tabular crystals ranging in size from 0.1 – 5 mm. Biotite is the second most abundant phenocryst phase (up to 10% of the rock) whereas blocky megacrystic K-feldspar phenocrysts, up to 1 cm, are a characteristic of this unit, but are low in abundance compared to plagioclase and biotite phenocrysts (< 2%). Quartz phenocrysts are rare, and are generally rounded or embayed where present. Intrusion #1 lacks amphibole or pyroxene phenocrysts and primary magnetite.

Intrusion #2 occurs as a WNW-oriented elongate body at depth that splits into two apophyses that form semi-circular stocks (both approximately 150-200 m in diameter) at shallower levels where they cut Intrusion #1. Both apophyses are in contact with and cut by Intrusion #3. The rock is a fine- to medium grained porphyry with abundant (20-30%) plagioclase phenocrysts up to 2 mm in length in a dominantly K-feldspar groundmass. Rare primary biotite and amphibole phenocrysts occur but the unit lacks quartz phenocrysts. Very fine-grained (< 0.2 mm) primary magnetite in the groundmass may be primary.

Intrusion #2A occurs in the southeast corner of the pit and is characterized by a very intense clay (kaolinite-smectite-pyrite) alteration throughout that forms a distinct textural and rheological argillic altered sub-domain termed the friable domain. Intrusion #2A forms a circular stock (250-300 m across) that tapers at depth. It intrudes the margin of Intrusion #1, but contact relationships with Intrusion #3 are not observed. It is a fine- to medium grained porphyritic rock, but the intense pervasive clay alteration obscures the primary mineral assemblage.

Intrusion #3 is the youngest large intrusive body. It forms a semi-circular stock near the center of Intrusion #1, west of the central Intrusion #2 stock and at depth to the west extends into a WNWelongated, subvertical dike like body. Intrusion #3 is a fine-grained porphyritic unit with 20-30% plagioclase phenocrysts up to 4 mm in length, and lesser quartz and biotite phenocrysts (both < 5%). Amphibole phenocrysts (5-10%) are more abundant than in the other intrusions but are commonly altered to chlorite. This intrusion is magnetic due to the presence of very fine-grained disseminated primary magnetite in the groundmass.

Porphyry-style sheeted to stockwork quartz veins occur with the potassic and white mica tourmaline alteration zones. Veinlets range in width from 0.1 mm to 1 cm, with most being 1-3 mm. Gold occurs as non-refractory, very fine free gold grains (typically less than 10 microns in diameter) that are associated with pyrite, and less commonly other sulfide phases (chalcopyrite, and sphalerite), as well as free grains attached to quartz, K-feldspar and albite. Both native gold and electrum (with up to 18 % Ag) have been identified. Other opaque minerals include pyrite, molybdenite, and sphalerite, with minor occurrences of tennantite, tetrahedrite, bournonite, chalcopyrite and gold- and bismuthtelluride. The average copper grade of the deposit is low (~ 200 ppm) but increases to typically between 300 and 500 ppm within potassic alteration (Baker et al., 2016).

The mine is an open pit delivering 13 Mtpa to the crushing circuit with a life of mine strip
ratio of approximately 1.29:1. Mining methods are by conventional open pit techniques with unit operations consisting of drilling, blasting, loading, and hauling by truck.

Ore and waste are mined in 10 m benches with truck hauling of ore to the primary crusher on the north east of the pit and waste to the south rock dump centered approximately 1 km south of the western edge of the pit.

The pit will be developed in four phases. The first two have been completed and mining of phase 3 is ongoing. The final pit will be approximately 1,360 m (east-west) x 1250 m (north-south) x 505 m deep.

The previous technical report entitled “Technical Report for the Kisladag Gold Mine, Turkey”, published by Eldorado Gold in March 2010 was based on the ore being processed in a conventional heap leach facility which consists of a three-stage crushing plant, an overland conveyor from crushing plant to heap leach pad, mobile conveyors, a radial stacker for placing the crushed ore onto leach pad, and a carbon adsorption facility for recovering dissolved gold onto activated carbon. The gold-loaded carbon is then stripped on site in a refinery and the final product is a gold doré bar.

The initial design capacity was 5 Mtpa for the first two years of operation, predominantly oxide material was processed during this time. The facilities were expanded to process 10 Mtpa and subsequently to 12.5 Mtpa. As mining has progressed deeper into the pit the proportion of sulphide has increased and become dominant; since 2016 oxide ore quantities have become negligible. Typical crushed product size is 80% passing 6.5 mm.

The existing process plant consists of:

Primary crushing and coarse ore stockpile.

Secondary screening and crushing.

Tertiary crushing and screening.

Crushed ore overland conveying and stacking.

Heap leaching.

Adsorption, desorption, regeneration (ADR) plant.

Electrowinning and gold smelting.

Reagent and air services.

Water services (fresh water, process water, potable water).

Subsequent evaluation for treatment of sulphide ore through heap leach process necessitated a change in the process flowsheet to achieve consistently higher gold recovery over the entire Kisladag ore body. Consequently in 2017, a conventional whole ore cyanide leach-CIP based process was developed and serves as the basis for the current evaluation.