Gold mineralisation within the CentroGold project is considered to be typical of mesothermal veinstyle, or orogenic-style gold mineralisation.

The host of the primary mineralisation at the CentroGold deposits is a coarse, equigranular intrusive of tonalitic composition, close to the contact with a fine-grained arenite. Rocks in the deposit have been significantly affected by hydrothermal alteration. Gold mineralisation is closely associated with sulphide content within zones of quartz-sericite-pyrite alteration.

Mineralisation at the Contact deposit is typically sub-vertical, with flatter lying high-grade zones hosted in rafts of sediment within the tonalite intrusion host rock. The Mineral Resource has been completed using two individual grade domains using a nominal 0.4 g/t gold cut-off grade for wireframing.

The Blanket deposit is a shallow dipping (approximately 20-30 degrees), tabular body of medium grade gold mineralisation. The Mineral Resource has been completed using five individual grade domains constructed using a nominal 0.5 g/t gold cut-off grade for wireframing.

Blanket Deposit
The reported Blanket Mineral Resource is contained within a volume defined by the following coordinates:
• 9,750,170 mN to 9,751,020 mN
• 364,240 mE to 364,820 mE
• 60 mRL to –180 mRL.

Mineralisation has a strike length of 850 metres, an across-strike length of 656 metres and runs from surface down to 240 metres below surface. Mineralisation is open at depth.

Contact Deposit
The reported Contact Mineral Resource is contained within a volume defined by the following coordinates:
• 9,749,325 mN to 9,750,620 mN
• 363,710 mE to 364,800 mE
• 60 mRL to –215 mRL.

Mineralisation has a strike length of 1,600 metres, an across strike width of approximately 300 metres, and runs from surface down to 275 metres below surface. Mineralisation is open at depth.

The pit optimisation was performed using NPVS. Before the block model was uploaded into NPVS, new attributes were created to apply costs and recoveries. A traditional drill and blast, excavator and truck operation was modelled.

A NPVS pit shell (revenue factor 1) was chosen as the basis of the design from the optimisation. The cutoff grade used was selected in the preceding Hill of Value study. This cut-off was higher than the economic breakeven cut-off determined by NPVS. Thus, all material with a grade above the economic breakeven cut-off and below the Hill of Value cut-off (0.9 g/t), was treated as low-grade ore, stockpiled and later reclaimed for processing at the end of the LOM.

The two orebodies, Blanket and Contact, are proposed to be mined simultaneously in a 24 hour per day operation. The optimisation indicated a preference to mine the higher-grade Contact deposit first, as well as the need to undertake a moderate pre-strip to enable reasonable volumes to be mined in the following two years.

To accommodate the volume of waste, three different waste dumps were designed, based on material type and previous licensing locations. A small dump was strategically positioned in front of the tailings dam, with all dumps a minimum of 200 m from the pit crest.

A decision was made to use a contract mining scenario – responsible for drilling, loading, hauling, waste dump and stockpile construction, reclaiming of ore to the crusher, drainage and road maintenance. Another contractor was modelled for blasting, explosive supply and explosives transport to site.

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The process considers primary, secondary and tertiary crushing, a ball mill, gravity concentration in the ball milling circuit, gravity concentrate intensive leaching, froth flotation, flotation concentrate carbon-in-leach, elution, electrowinning and smelting to doré bullion.

The plant was designed for an annual throughput of 2.5 million tonnes per year, being the run of mine (ROM) unloaded directly from trucks to the primary crusher or being stored on an intermediate stockpile on the ROM pad and reclaimed by front-end loaders to the crusher. The crushing operation would be at 4,380 hours per year and a nominal rate of 571 tonnes/ hour. The plant was modelled having an effective utilisation of 90% considering the material being reclaimed from an intermediate stockpile at a nominal rate of 317 tonnes/ hour, with ~1.7 g/t Au average head grade.