The host rocks at Rupice comprises Middle Triassic limestone, dolostone, calcareous and dolomitic marl, and a range of mostly fine-grained siliciclastic rocks including cherty mudstone, mudstone, siltstone and fine grained sandstone. The main mineralised horizon is a brecciated dolomitic unit that dips at around 50o to the northeast and has been preferentially mineralised with base, precious and transitional metals. The Triassic sequence and has been intensely deformed both by early stage ductile shearing and late stage brittle faulting.

The Rupice polymetallic mineralisation consists of sphalerite, galena, barite and chalcopyrite with gold, silver, tetrahedrite, boulangerite and bournonite, with pyrite. The majority of the high-grade mineralisation is hosted within the brecciated dolomitic unit, which is offset and cut by northwest striking, westerly dipping syn-post mineral faulting. This faulting displaces the mineralised body up to 20 metres in places. Thickening of the central portion of the orebody occurs where these faults flexure and deform. Mineralised widths up to 65 metres true thickness are seen in the central portion of the orebody.

To date, the massive sulphide mineralisation at Rupice has a defined strike length of 650 metres, with an average true-width thickness of around 20 metres. However, mineralisation at Rupice still remains open towards the north and down-dip to the south.

The Vares Silver Project hosts two Mineral Resources; the Rupice underground deposit (“Rupice”) and the Veovaca open pit deposit (“Veovaca”). Veovaca open pit removed from scope of study.

Access to the underground workings will be via two declines developed from the surface accessing the orebody via further development of ramps, level access drives and footwall drives. All the development access will be suitable for trackless equipment.

The underground stoping will be divided into two main mining method zones:
• Transverse Longhole Open Stoping zone (“TLOS”)
• Longitudinal Longhole Open Stoping zone (“LLOS”)

The TLOS zone will be below the 1,065 level and the LLOS zone will be from and above the 1,065 level. TLOS will be used in areas where the ore zone thickness is greater than 20 m. Stopes will be oriented in a transverse fashion with stope access drives orientated from the footwall towards the hanging wall, perpendicular to the general orebody strike. LLOS will be used in areas where the ore zone thickness is less than 20 m. Stopes will be oriented in a longitudinal fashion along a strike drive.

Primary stopes represent the initial phase of production mining within the TLOS section of the mine. Primary stopes are mined in a “chequerboard” fashion on each level, with temporary pillars left between the primary stopes. The primary stopes are then backfilled with either Cemented Aggregate Fill or Paste Aggregate Fill, or a combination of both. Once the fill has cured, the temporary pillars between the primary stopes can then be mined out. These pillars are known as secondary stopes.

The primary access to the underground workings will be via two separate access declines developed from surface. A third, primary main return airway decline has replaced the previously proposed return air raise-bore shaft.

Following the excavation of the box cuts and installation of appropriate portal support systems, the declines will be developed with dimensions of 5.5 m wide X 5.5 m high. The main return airway and middle access decline will be developed at a maximum gradient of 14 % (1 in 7) while the lower access decline will be developed at a maximum gradient of 16 %
(1 in 6). The lower access decline will serve as the main ingress route into the mine while the middle decline will serve as the main egress, hence allowing for dedicated traffic in one direction with minimal disruption to the hauling operations. The remaining ramps going up and down from the different underground access positions are all developed at the 1:7 inclination.

Secondary development will consist of level access drives that are driven to connect the ramps with the footwall drives on each sub-level. The footwall drives are designed with a minimum stand-off of 25 m from the orebody and will have dimensions of 5.0 m wide X 5.5 m high.

The sub-levels will be spaced at 20 m vertical intervals. The lower 12 sub-levels will serve as access to transverse longitudinal stopes while the upper five sub-levels will be used as access for longitudinal long hole stopes. The transverse stopes will be accessed along horizontal cross-cut drives leading from the footwall drive at dimensions of 5.0 m wide X 5.0 m high and developed at right angles to the strike of the deposit. The cross cuts will be spaced 15 m apart along strike to adequately traverse the deposit and provide for a 15 m stope strike drilling envelope in a primary-secondary stope sequence and retreating from the hanging wall to the footwall (direction).

The longitudinal stopes will be accessed along a strike orientated ore drive, with dimensions of 5.0 m wide X 5.0 m high, which exits the sub-level access drive. There will be one ore drive per sub-level for the longitudinal stopes. The ore drive is developed along strike to the distal end of the sub-level and then stoping occurs in a retreat direction along the ore drive. For the longitudinal and transverse stopes, the mine design of the rings has the holes spaced to optimise drilling and to allow for a suitable Powder Factor whilst not over breaking the stopes and fracturing the surrounding secondary stopes. The loading of the blasted material be at the intersection point of the crosscut and the footwall drive and hauled via the internal ramp and decline to surface and tipped onto one of three Run of Mine (“ROM”) stockpiles depending upon the grade.

The mine design comprises largely of the access and ventilation portal areas, main declines, trackless ramps sub-level access drive, and the sub-level footwall drives.

The long-hole drilling metres are calculated from the stope drill and blast designs concluded, which assume a factor of 7 tonnes of ore per blast hole. Two longhole drill rigs will be employed to do all the slotting, the smaller level ventilation rises and the stope drilling.

The mining cycle will consist of the following sequential activities:
• ore drive development
• hanging wall cable bolting
• stope slotting
• stope production drilling
• charging and blasting
• Remote-controlled stope loading
• truck loading at stockpiles
• hauling
• backfill wall installation
• backfill plug pour
• complete stope backfilling
• allow sufficient time to cure prior to starting any neighbouring stope slotting activities.

The Rupice Underground Mine production rate is designed to match the nameplate capacity of the Vares Processing Plant at 800,000 tonnes per annum. Stope development of the Rupice Underground Mine will start eight months prior to commissioning of the Vares Processing Plant. At the time of starting commissioning there will be approximately 210,000 tonnes of high-grade ore, 190,000 tonnes of medium-grade and 26,000 tonnes of low-grade ore – in total about six months at full production. During the mine life, sufficient ore is produced to maintain the Vares Processing Plant production rate, with excess lowergrade ore being stockpiled for treatment later in the mine life. During the later stages of the mine life, the underground production rate drops off due to reduced stoping areas being available and the cyclic nature of the cut-and-fill mining methods.

Crushing
ROM material will be deposited by the underground trucks at one of three ROM stockpiles near the portal.

A front-end loader will reclaim ore from the stockpiles in accordance with the blending regime required by the processing plant and deposit the ore into the blend ore bin, (crushing plant feed bin). For longer tramming distances from stockpiles the loader will load the two 30 t trucks provided and they will travel to and tip into the blend ore bin. The blend ore bin has a nominal capacity of 85 t and will be equipped with a 600 mm static grizzly to prevent oversize material from entering the crushing circuit. A vibrating grizzly feeder will feed the material from the bin to the primary crusher which will allow finer material to bypass the crusher.

The primary crusher will be a single-toggle jaw type crusher and will be designed to reduce the feed size from 80% passing 427 mm to 80% passing 150 mm. The crushed material will combine with the undersize material from the grizzly feeder which will lower the 80th percentile of the particle size distribution from 150 mm to 121 mm. The ore will then report to the secondary cone crusher which would be operated in open circuit. The secondary crushing stage would further reduce the 80% passing size of 121 mm to 51 mm. The secondary crusherdischarge would then be conveyed to the triple deck sizing screen. The top, middle and lower deck screen apertures will be 75 mm, 28 mm and 12 mm respectively. Oversized material on the sizing screen decks will report to the tertiary cone crusher. The tertiary cone crusher is operated in closed circuit and will reduce the feed size from 80% passing of 50 mm to 12 mm. The tertiary crushed product is combined with the secondary crusher product prior to reaching the triple deck sizing screen. The undersize of the sizing screen provides the final product of the crushing circuit and will produce an 80% passing crushed ore product of 7mm.

The same crushing plant will also be used to produce aggregate for both PAF and CAF to the backfill plant. When producing PAF the crushing circuit will operate exactly as described above to produce the crushed ore material but will be fed with waste rock. A diverter gate system will direct the undersize of the sizing screen to a dedicated PAF stockpile that provides material with a 100% passing size of 12 mm. When producing CAF the crushing operation is truncated and will bypass the tertiary crusher closed loop circuit. The undersize of the screen will be redirected to a CAF stockpile that provides 100% passing size of 75 mm. The crushing plant has been sized to handle the combined monthly requirements for both ore and aggregate. It will be operated on a batch basis, utilising available stockpile and coarse ore bin capacity.

Crushed ore will be trucked 24.5 km from the Rupice Surface Infrastructure site to the Vares Processing Plant and end-dumped into a crushed ore hopper with a capacity of 37.5 t. The crushed ore will be fed by a belt feeder to a belt conveyor. The belt conveyor will transport the crushed ore to a diverter gate, where it will be discharged into two coarse ore bins. Each bin provides a live residence time of 23 hours and a corresponding capacity of 2,260 tonnes of ore on a wet basis. Ore will be reclaimed from the bins by belt feeders and discharged to the ball mill feed conveyor.

The crushed ore bins provide surge capacity between the crushing system and the ball mill and will be independently filled and discharged. The throughput to the mill will be controlled by adjusting the speed of the crushed ore bin belt feeders based on the ball mill feed conveyor weightometer output and the mill control system set-point.

Grinding
The grinding circuit consists of a ball mill and cyclones. The grinding circuit will be designed to reduce ore from an 80% passing size of 7 mm to 40 µm. The ball mill will be a single pinion overflow mill, operating in a closed circuit. The mill has an inside diameter of 4.3 m and an effective grinding length of 7.5 m. The mill receives crushed ore and process water at a variable flow rate to achieve the correct pulp density. Lime, zinc sulphate and sodium metabisulphite (SMBS) are also dosed to the ball mill to condition the ore prior to the flotation circuit. The ball mill discharge passes over a slotted trommel screen with an aperture size of 10 mm x 25 mm. The ball mill will be charged with high chrome grinding media, ranging in diameter from 25-40 mm utilising the grinding building hoist and ball kibble.

Operators will monitor the grinding mills discharge density, cyclone overflow and underflow densities, power draw, cyclone pressure, and other parameters to maintain a product size of 80% passing 40 µm.

The 2021 DFS process design is based on treating ore from the Rupice Underground Mine through a sequential flotation process to produce a silver-lead concentrate and a zinc concentrate.

The Vares Silver Project has two processing sites; the Rupice Surface Infrastructure site and the Vares Processing Plant site. The Rupice Surface Infrastructure site, which is a greenfield site, is located above the Rupice Underground Mine site.

ROM hauled to surface from the Rupice Underground Mine will be deposited onto one of three surface stockpiles based on grade, from which the ore will be reclaimed, by a front-end loader, (and trucks, depending on distance of the stockpile from the crusher feed bin) into the three-stage crushing plant feed bin. Waste rock will be processed through the same crushing plant to produce the required aggregate materials used for the backfill plant. The ore and waste rock will be processed on a batch basis through the crushing plant and the plant ........