The Timok Project is located within the north-western part of the Timok Magmatic Complex (TMC) in eastern Serbia.

The dominant mineral prospects in the clastic sedimentary rocks along the western margin of the TMC are relatively low-temperature auriferous deposits that share many characteristics with Carlin-type gold deposits. The interpretation of the sediment-hosted gold prospects within the Project area as Carlin-type is based upon the following criteria (Knaak et al., 2016):
• Character of the sedimentary host;
• The metal association (gold, arsenic, mercury, thallium, sulphur and antimony);
• The fine-grained nature of the gold, high gold-to-silver ratio and alteration types including argillisation, decarbonisation, and locally, addition of quartz.

Four important mineralised areas have been defined in the Potaj Cuka Tisnica exploration licence, comprising of the Bigar Hill deposit, the Korkan and Korkan West deposits and the Kraku Pester deposit. All four zones share a similarity of mineralisation style, which has been most clearly defined at the Bigar Hill deposit and are associated with a large hydrothermal system that has been identified within the Timok Project.

Bigar Hill Deposit
Gold mineralisation at Bigar Hill is located principally along two stratigraphic horizons, with lesser amounts present along peripheral steeply dipping fracture zones within the clastic rocks and an andesite sill. A lower zone is localised along the unconformable and brecciated lower contact between the clastic S1 and isolated karst-infill zones above the KLS unit. The most continuous horizons lie at shallow stratigraphic levels along the contact between the S1 and S2 units, forming a middle zone. Above this zone, gold mineralisation occurs within the andesite intrusive unit.

Mineralisation is continuous and follows the dips of the stratigraphy. It has a north-south extent of approximately 900 m and an east-west extent of approximately 900 m. Mineralisation is largely from surface, and in the south its depth extent is greatest (approximately 500 m). Depth extent reduces to 200–300 m below surface moving further north. There is a small zone in the centre, where mineralisation starts from approximately 80 m vertical depth from surface.

Korkan Deposit
Mineralisation at the Korkan deposit is generally southeast-northwest trending and shares similar characteristics with the Bigar Hill deposit. Unlike Bigar Hill, stratiform gold mineralisation at Korkan occurs primarily along the unconformable and breccia-like lower contact zone of the clastic S1 sequence against the underlying KLS limestone unit, and in karst-infill zones at the upper boundary of the KLS limestone unit.

Mineralisation is less continuous at Korkan compared to Bigar Hill, due to higher structural complexity. As at Bigar Hill, it tends to follow the dips of the stratigraphy. The mineralised footprint has a northeast-southwest extent of approximately 1,100 m and a northwest-southeast extent of approximately 1,100 m. Mineralisation commences from surface and can be traced to a maximum depth of 400 m below surface.

Korkan West deposit
The Korkan West deposit is the newest discovery within the Project. It lies between the Bigar Hill and Korkan deposits, along a northwest trending structural corridor. The Korkan West deposit shares many characteristics with the Bigar Hill deposit, located approximately 1 km to the southeast, and the Korkan deposit located approximately 1 km to the northeast. Almost all mineralised intervals are manifested as oxide and transitional weathering states. Host rocks for gold mineralisation are: (1) oxidised fine to very coarse-grained (0.1 mm to 2 mm) sandstone belonging to the S1 or S2 units; (2) conglomerate layers containing quartzite clasts and/or not limestone clasts (S1 or S2 units). Mineralisation at S2/S1 contact can commonly be observed.

The orientation of structures in the Korkan West area are currently interpreted to be striking predominantly along a west-northwest to east-southeast orientation. These structures are located within a 300 m wide and 600 m long corridor and were most likely the feeder zones for hydrothermal fluids.

Kraku Pester deposit
The Kraku Pester deposit is located in an embayment at the north-western tip of the Potaj Cuka monzonite, consisting of a thermal aureole across a variably disrupted stratigraphic sequence of metamorphosed shale, marls and limestone metamorphosed to calc-silicate phyllite and marble, and tuffaceous rocks. Unlike Bigar Hill, gold mineralisation at Kraku Pester is hosted in brittle fault rocks composed of pyritised fault breccia to cataclasite, with relatively higher gold concentrations being associated with finer-grained cataclasite. Gold deposition is interpreted as being relatively late in the geological-structural evolution, post-dating the emplacement of the monzonite.

Conventional open pit mining with rigid body mining trucks, hydraulic excavators and wheel loaders was chosen for the Project. The material extracted from the Project’s three (3) pits: Bigar Hill, Korkan West, and Korkan, will be loaded into trucks by hydraulic excavators and transported to its destination. Each pit is mined in three phases and the Project is mined over a 7-year mine life, with one (1) year of pre-production and an additional year at the end of the mine life for stockpile reclamation.

Ore material, either oxide or transitional material, will be sent to the crusher or an ore stockpile; marginal material will be stockpiled to be reclaimed in the operation’s last year. Reclaimed stockpile material will be loaded onto trucks by wheel loaders and sent to the crusher. After the crusher, the ore material will be sent to the leach pad. Waste material will be sent to waste piles located near each pit, and sulphide material above the sulphide cut-off grade will be stockpiled near the waste piles for potential future reclamation.

The mine will be operated by an owner-operated fleet of 60 T trucks and related equipment seven (7) days a week, 24 hours a day in two (2) 12-hour shifts. The operation considers two weeks of adverse weather conditions, therefore running 350 days a year.

The mine plan is based on an ore production rate of 2.5 Mtpa sent to the leach pad. The oxide ore has a higher recovery rate at the leach pad than does the transitional ore and was therefore favoured in the optimization process. A total of 67.6 Mt of material is extracted over the Project’s life-of-mine.

Bigar Hill Pit Design
Recommended inter-ramp slope angles vary from 36° to 58° based on wall orientation, overall wall height, geotechnical domain, and controls on slope stability. Inter-ramp slope heights are limited to 100 m, after which a geotechnical berm (or ramp) with a minimum width of 15 m is required. The inter-ramp height limits and geotechnical berms provide flexibility in the mine plan to mitigate potential slope instability; access for slope monitoring installations; and working space for in-pit wells, drains, and other water management infrastructure. All final pit slopes are assumed to be excavated using controlled blasting. Depressurization of the pit slopes is required and should be achievable with a combination of vertical wells and horizontal drains.

Korkan Pit Design
The slope designs assume final walls will be excavated using controlled blasting, consistent with the approach proposed for the Bigar Hill pit. The recommended inter-ramp slope angles vary from 36° to 53° based on wall orientation, overall wall height, rock mass quality, and structural controls on slope stability. Inter-ramp slope heights are limited to 100 m after which a geotechnical berm (or ramp) with a minimum width of 20 m is required. Depressurization of the pit slopes is required and should be achievable with a combination of vertical wells and horizontal drains.

Korkan West Pit Design
The slope designs assume that final walls will be excavated using controlled blasting. The recommended inter-ramp slope angles vary from 28° to 54°; based on overall wall height, wall azimuth, rock mass quality, and geological structures. Inter-ramp slope heights are limited to 50 to 100 m after which a geotechnical berm (or ramp) with a minimum width of 15 to 20 m is required. Depressurization of the pit slopes is required and should be achievable with a combination of vertical wells and horizontal drains.

A three-stage crushing will be employed to produce a crush size P80 of 17 mm (P100 of 25 mm).

PRIMARY CRUSHING
ROM ore will be transported in mine trucks to the crushing plant where it will be dumped into a 150- tonne feed bin equipped with a static grizzly. Any oversized rocks not passing through the grizzly will be broken with the use of a rock breaker. An apron feeder will reclaim ore from the bin, and a vibrating grizzly feeder will feed the primary jaw crusher.

The jaw crusher will be a 1200 mm x 830 mm opening crusher, model CJ412 or equivalent, and will operate with a closed side setting (CSS) of 90 mm. The jaw crusher and vibrating grizzly feeder undersize will be combined and conveyed to the vibrating screen deck.

SECONDARY AND TERTIARY CRUSHING
The vibrating screen will be a 2.4 m by 6.2 m double-deck 10 deg inclined linear motion step deck screen with 70 mm and 25 mm screen deck apertures.

The vibrating screen classifies the combined feed stream combined from the primary, secondary and tertiary crushers discharge into:
• Top deck oversize: secondary crusher feed;
• Bottom deck oversize: tertiary crusher feed; and
• Bottom deck undersize: crushed product.

Each of the cone crushers is fed from a dedicated 60 t crusher feed bin via a dedicated belt feeder (one (1) bin and one (1) belt feeder per crusher). Secondary and cone tertiary crushers will be CH660 or equivalent machines with 25 mm and 15 mm CSS respectively and will provide a sufficient size reduction to the feed material. The cone crushers discharge onto a belt conveyor, combined with the primary crusher discharge, and are conveyed to the vibrating screen for the size separation.

A dust collection system will be installed to minimise dust generation throughout the crushing and screening circuits while provisions for dust suppression water sprays have been allowed for in the ROM ore bin, transfer chutes, and in the screen-house area.

Oxide and transitional ores from Bigar Hill, Korkan West, and Korkan deposits will be processed using conventional heap leach technology, adopting a Heap Leach Fill (HLF) design. The design stacking rate is based on processing 2.5 Mtpa, at an average gold grade of 1.07 g/t, and an overall discounted gold recover of 84.9% and 71.8% for the oxide and transitional ore types respectively.

The HLF pad will be constructed in two (2) separate phases: 9.9 million tonnes in Phase 1 with an addition of 9.3 million tonnes during Phase 2, totalling to 19.2 million tonnes of ore processed during 8 years of mine life. Phasing of the Project includes the earthworks and pad construction and lining and reduces initial capital expenditure.

Ore will be crushed in the three-stage crushing plant and then trucked to the HLF pad. An agglomeration circuit, considered for the high clay ore, will be used intermittently on an “as required” basis. The leach pad will be irrigated with Barren ........