Segilola is an orogenic-style lode gold deposit which occurs within a regional-scale shear zone.

Host rocks comprise an overturned sequence of high-grade amphibolite-facies metasediments intruded by a large, possibly differentiated, granodiorite sill-like body. The mineralisation is developed within a series of steeply dipping, tabular, very continuous, latestage quartz-pegmatite veins that do no exhibit any form of significant deformation such as folding or faulting. The geological and mineralogical characteristics of the mineralised veins are consistent throughout both the strike and down dipextents of the known resource.

Drilling results demonstrate that gold mineralisation occurs in fractured pale to dark grey coloured smoky quartz veining, sheared pegmatite, and silica/chlorite/carbonate alteration. The mineralisation is hosted in three steeply dipping vein sets or lodes; the Hanging Wall Lodes (Lodes 100 and 300) and the Footwall Lode (Lode 200). Together these form an elongate mineralised zone striking 010º and dipping 60º to 70º towards the west within a single shear zone, primarily in biotite gneiss. The currently drilled mineralised zone is approximately 2,000 m in strike length, between 70 m and 200 m in depth, and between 2 m and 20 m in true thickness.

The mineralogy of the Segilola deposit is characterised by its general simplicity and consistency. The gold is entirely non-refractory and commonly occurs as visible particles within either pegmatitic quartz-feldspar veins or foliated biotitic selvedges to the veins. There are no significant trace element associations such as silver with gold. However, metallurgical assaying indicates slightly elevated copper (250 ppm to 300 ppm) and mineralogical studies suggest a gold-tellurium association.

Two styles of gold mineralisation are observed:

• Narrow, 1 m to 3 m thick Hanging Wall Lodes within silicified biotite schists (DGS). These lodes locally contain 5 µm to 20 µm grains of visible gold and are developed in the hanging wall to the main (footwall) lode. These lodes appear to have different controls to the footwall lode and have a more vertical continuity over shorter strikelengths.

• Wide, up to 15 m, ‘footwall’ mineralisation within a characteristically grey-green, strongly silicified zone of biotite schists and gneisses (SZQ1).

The mineralised lodes generally comprise highly silicified fine-grained, foliated biotite gneiss typically intruded by both discordant and concordant pegmatitic quartz-feldspar veins.

Shearing, fracturing, and alteration influence the location of gold mineralisation. This relationship has generated multiple zones of gold mineralisation hosted by shears now represented by chlorite and calcite alteration, together with quartz veining and pyrite development.

Minor sulphides, typically pyrite, are associated with the lodes. Macroscopic observations show that sulphide grains and blebs are often aligned with foliation, commonly following either biotite-rich laminae or near pegmatite boundaries. There is also, however, a common generation of pyrite occurring along fractures or as quartz-pyrite tension gashes, highly discordant to the foliation. A cursory examination suggests most of these do not contain pyrrhotite. These either relate to a late episode of mineralisation, or to remobilisation of sulphides.

Native gold is visible in both altered wall rock and in quartz-feldspar veins. It occurs with petzite (a silver gold telluride), within pyrite, and quartz veins. The typical size of native gold blebs is approximately 10 µm. Gold, either as native grains, flakes and blebs occurs together with gold-on-pyrite in alteration zones, along tension gashes, hair-like fractures, joints, and minor faults.

The Segilola Gold Project will be operated primarily as a contract mining operation with all mobile equipment to be provided, operated, and maintained by a mining contractor(s) over the life of the Project. Conventional open pit mining methods using excavator and truck fleets will be used. Thor will provide fixed installations including contractor area establishment, workshops, offices, and first aid facilities.

There are four well defined weathering horizons present, allowing the material to be mined according to classification as residual soil, oxide rock, transitional rock, and fresh rock. The vast majority of material is fresh rock.

Drilling rigs operated by the contractor will be Epiroc T45/50 class top-hammer drills with the capability to drill holes from 89 mm to 140 mm in diameter. Ore blasting will be done on five metre benches, while waste blasting will be conducted on 10 m benches where possible. A set of blast patterns ranging in powder factor from 0.43 kg/m3 to 1.07 kg/m3 will be applied depending on the material type.

Narrow ore zones will require the implementation of careful blasting techniques to minimise dilution and maximise ore recovery, namely the use of “Blastmaster” bench planning to optimise blast shapes/geometry and sequencing, choke firing where possible to minimise ore movement, blast initiation timing to control movement, the use of blast movement indicators, and a refinement of blast design parameters based on results obtained.

Blasting will be done with pumped emulsion as water is expected in the blast holes.

The mining contractor will use 200 t hydraulic excavators (12.5 m3 bucket capacity) and 90 t payload rear dump trucks. Excavators will be in backhoe configuration to allow flexibility for mining both ore and waste.

Waste mining will be performed using a double-bench method, where possible, in order to reduce ancillary equipment costs, taking a full 10 m cut with each pass. Ore mining will be on two 2.5 m flitches to reduce the chance of dilution whilst still providing a sufficient bench height for the required production rates.

Grade control drilling and mining of the ore will only take place during dayshifts so that the Thor technical department can guide excavations to minimize ore dilution and loss.

The production equipment will be supported by ancillary equipment such as dozers and graders to achieve level graded floors, smooth out blast heave, and provide face cleanups. Water carts will be employed for dust suppression, using water sourced from pit dewatering and other storage dams when necessary.

A total of 75% of the Run of Mine (ROM) is planned to be re-handled due to the substantial stockpiling planned. This will be done using a front-end loader (FEL), such as a Caterpillar 988, with 6.4 m3 bucket capacity. The ROM pad and stockpile area will be located adjacent to the processing plant at the southern end of the west waste dump. All waste rock from the pre-strip period and initial months of mining will be used to create the flat area for the ROM pad and ore stockpiles. The front-end loader may need to be supplemented by a truck from the mining fleet when ROM pad hauls exceed 200 m.

Open pit dewatering requirements have been assessed based on limited groundwater information. The assessment has estimated the inflow into the open pit from groundwater sources could range from 60 m3/day to 600 m3/day. The contractor costed the provision of 3 Sykes HH160i pumps, which can each provide 350 m3/h capacity with a head of 100 m).

Sub-horizontal drains will be used to promote passive drainage of the pit walls, typically installed from benches in the pit walls, with a horizontal spacing of 10 m to 30 m between drains. Drilled diameters will be 75 mm to 100 mm, with a 50 mm diameter high-density polyethylene (HDPE) of unplasticised polyvinyl chloride (uPVC) slotted screen installed.

The plant is designed to operate 365 day/year, 24 hours/day, with a design utilization of 91.3%, for a nominal ore throughput of 81.3 tph and design ore throughput of 84.5 tph. Production throughput utilises 86.6% of design utilization, resulting in an average LOM annual production of 625,000 tpa.

The process plant was initially designed for a ROM throughput of 500,000 tpa. During the DFS study, to better align with the mine design and optimise project economics, the process plant throughput capacity was increased to 650,000 tpa. This increase in size of the processing facility also allows for operating flexibility and future expansion capacity.

The ROM pad will be located at the south east corner of the plant site. ROM with a nominal top size of 600 mm will be delivered by haul trucks from the open pit mining operation and will either be dumped directly into the ROM bin, or stockpiled on the ROM pad. If oversize rocks bridge the static grizzly, a mobile rock breaker will be used to clear the grizzly.

The crushing circuit consists of a single-stage jaw crusher, and has been sized based on the capacity of the jaw crusher selected for the ROM ore top size. The crushing plant will operate at a crushing rate of 150 tph, treating ore from a maximum lump size of 600 mm to a product top size of 160 mm.

The crusher circuit product will be transferred to the crushed ore stockpile. From the stockpile, the material will be withdrawn using either of the two apron feeders that will discharge onto the mill feed conveyor, which will transfer the ore to the SAG mill feed hopper. The ore will be mixed with feed water in the mill feed hopper. Hydrated lime, used for pH control, will also be added directly onto the mill feed conveyor.

The grinding circuit will consist of a SAG mill, and ball mill in closed circuit with hydro cyclones, having a design throughput of 81.5 dry tph and grinding to a nominal cyclone overflow P80 of 106 µm.

One third of the cyclone underflow will gravitate to the Knelson concentrator scalping screen to remove +2 mm material. Screen oversize and the remaining cyclone underflow will gravitate into the ball mill feed chute and back into the mill for grinding. Screen undersize will report to the Knelson concentrator where free gold will be recovered from the slurry. The Knelson tails will gravitate back into the ball mill feed chute.

The Knelson concentrator will operate in batch mode and the feed will be stopped periodically and the gravity concentrate flushed into a settling cone located beneath the concentrator. The concentrate will be drained into the Acacia reactor every 24 hours for intensive leaching in cyanide. Cyanide, sodium hydroxide, and leach aid will be mixed in the heated intensive cyanidation reactor (ICR) leach solution storage tank before being pumped to the ICR. The leach solution will be used to fluidise the concentrate bed to ensure good contact between the solids and the circulating leach solution. Pregnant solution from the reaction vessel will be transferred to the ICR pregnant solution tank and the gold will be recovered by a dedicated electrowinning circuit.

Gold and silver leaching will take place in a conventional CIL type circuit with five leach tanks (no carbon) and five adsorption tanks containing activated carbon, which allows reduced carbon inventory and reduces locked gold in the circuit, whilst target solution tails grades can be maintained if tanks are off line.

The loaded carbon recovery screen will be located above the elution column in the adjacent elution building, as close as possible to CIL tank no. 1.

Slurry containing activated carbon will be pumped from the first adsorption tank and pass over the loaded carbon screen. The screened slurry will be discharged back to the adsorption tank and the recovered carbon will gravitate to the carbon storage tank for the elution circuit.

The loaded carbon in the carbon storage tank is washed with water and then enters the elution column. Elution is carried out at high temperature and pressure, without the use of cyanide. Elution is carried out at 150°C and 0.5 MPa, with a 5% NaOH solution. Elution recycle time will be 6 to 8 hours, and electrowinning will be carried out at a voltage of 2.4 V to 3.0 V, and a current of 250 A. Overall elution cycle time will be 12 to 14 hours.

Elution solution (eluate) containing dissolved precious metals will be passed through an electrowinning cell to plate out the contained gold.

Precious metal recovery and refining will be carried out in a secure building.

Gold sludge is thoroughly washed in hot water. Silver and base metals are then removed from the sludge by leaching with nitric acid to form soluble nitrates. After leaching with nitric acid, the dried gold sludge is mixed with a range of fluxes and smelted at 1,100°C to produce bullion. Bullion will be stored in a vault prior to transport and refining off site, although the intention will be to remove bullion immediately off site by helicopter transfer to Lagos International airport for onward transport to the refiner.