The Skouries project is a gold–copper porphyry deposit located within the Halkidiki Peninsula of northern Greece. The project, currently under development, forms part of the Kassandra Mines complex.
Canadian firm Eldorado Gold Corporation owns the Skouries project through its 95% owned subsidiary Hellas Gold. The company acquired the Greek gold–copper porphyry deposit through its acquisition of European Goldfields (Hellas Gold) in 2012.
Construction of the Skouries project began in 2013. However, development was suspended in 2016 and the mine entered care and maintenance in December 2018 due to permit delays.
In February 2021, an amended investment agreement was signed with the Greek Government. The project feasibility study results were published in December 2021.
Eldorado Gold board is expected to take the final decision to resume construction at Skouries in the second half of 2022.
The project, designed as a two phase mining operation, is expected to have a mine life of 20 years.
Location and site details
The Skouries project is situated within the Kassandra Mines complex around 100km east of Thessaloniki. It forms a part of a complex that includes a group of mining and exploration concessions across a 317km2 area.
Besides Skouries, the complex also features the Olympias and Stratoni Mines. Currently, the Olympias Mine is in production, while Stratoni is on care and maintenance.
The Skouries project is situated at an elevation range of 350 metre above sea level (masl) to 620 masl near the village of Megali Panagia.
The Property includes concession numbers OP03, OP04, OP20, OP38, OP39, OP40, OP48, and OP57, with a combined area of 55.1km2.
Hellas Gold owns mining rights over these concessions until 7 April 2024. The tenure can be extended twice for two 25-year durations.
Geology, mineralisation and reserves
The Skouries deposit is centred on a small porphyry stock with a 200m diameter surface expression.
The project’s mineralisation is found in stockwork veins, veinlets and disseminated styles that are typical of a porphyry.
Mineralisation testing to a depth of 920m indicates the orebody is open at depth. Nearly two-thirds of the measured and indicated resources occur outside of the porphyry.
According to the feasibility study, Skouries project is expected to produce on average 140,000oz of gold and 67 million pounds of copper per annum, over 20 years mine life.
The property’s open pit combined Proven and Probable Mineral Reserves are 59.6 million tonnes (Mt) with an average grade of 0.57 g/t Au and 0.40% Cu.
The underground deposit is estimated to contain 87.5 Mt with an average grade of 0.90 g/t Au and 0.57% Cu.
Mining and ore processing
Skouries will be mined using open pit and underground mining techniques. The mineral processing plant will produce a gold-copper concentrate.
The Skouries mine is proposed to be developed in two phases.
During Phase one, ore will be produced through open pit operations and from underground mining, for nine years.
The second phase will involve mining from the underground mine for an additional period of 11 years.
The Phase I mill feed rate will be 8.0 Mtpa, comprising a nominal 5.5 Mtpa from the open pit mine and 2.5 Mtpa from the underground mine.
Eldorado Gold will commence Phase II mine development in Year 4 to maintain feed rate.
In the first four years of Phase II, the mill feed rate will be maintained at 8.0 Mtpa by reclaiming low-grade ore stockpiled during the first phase.
The rate will be maintained through Year 13 and from Year 15 Phase II mill feed will be 6.5 Mtpa. The figure will further reduce in Years 19 and 20 following the depletion of reserves.
Both open pit and underground operations will use conventional mining techniques.
The open pit mine infrastructure will include ancillary facilities services to support Phase I open pit mine production. The surface ancillary facilities are located near the open pit access ramp and primary crusher dump pocket. The ancillary facilities comprise a production services building, a surface workshop, a warehouse, and surface fuel storage.
During Phase II, the ancillary facilities will be developed underground to support the mining and material handling methods.
Underground services such as egress, dewatering, ventilation, compressed air, power, and communications and control that will be developed in the Phase I will be expanded during Phase II.
The mining project will also include waste management and water management facilities.
Open pit mining will generate overburden and waste rock, underground development will create waste rock and mineral processing operations will generate tailings.
The waste streams will be stored on surface, although most of the tailings will be used underground as paste backfill.
The Skouries Project’s high voltage substation has a power capacity of 51 MW.
The substation is connected to the national power grid with a newly constructed overhead 6 km long 150 kV transmission line.
Agreements and contractors involved
The Skouries Property’s technical report was prepared by AMC Mining Consultants (Canada).
ENOIA S.A. Athens, Omikron Kappa, GAL and Paterson & Cooke conducted the basic and detailed engineering for the project.
In September 2022, Eldorado Gold signed a mandate letter with Greek banks for a €680m project finance facility to restart construction at Skouries.