Perseus Increases Edikan’s Inventories of Mineral Resources and Ore Reserves

Figure 1

PERTH, Western Australia, July 18, 2022 (GLOBE NEWSWIRE) — Perseus Mining Limited (ASX/TSX: PRU) has completed a Feasibility Study on the Nkosuo Project, located approximately seven kilometres north-northwest of its Edikan Gold Mine in Ghana, adding substantial Mineral Resources and Ore Reserves to Edikan’s previously published inventory.

HIGHLIGHTS

• Indicated Mineral Resources¹ at Nkosuo amount to 14.5Mt at 0.91g/t for 422,000 ounces of contained gold, and Inferred Mineral Resources are estimated at 0.95 million tonnes grading 0.90 g/t gold containing 27,000 ounces of gold at 30 June 2022.

• Probable Ore Reserves¹ total 10 million tonnes of ore grading 1.04g/t gold and containing 332,000 ounces of gold.

• Planned processing of the Nkosuo Ore Reserves in the Edikan mill is expected to increase the life of the Edikan operation by 18 to 24 months, extending the mine life to FY2027.

Nkosuo Measured and Indicated Mineral Resources as at 30 June 2022

1  Refer to Notes in the individual tables of Mineral Resources and Ore Reserves.

Nkosuo Proved and Probable Ore Reserves as at 30 June 2022

1  Refer to Notes in the individual tables of Mineral Resources and Ore Reserves.

Perseus’s Managing Director and CEO Jeff Quartermaine said:

“The addition of Mineral Resources and Ore Reserves from the Nkosuo Project adds significantly to the mine life at Edikan Gold Mine, ensuring operations can continue while Perseus conducts further exploration on the recently acquired Agyakusu Exploration Permit and two other adjoining Exploration Permits that are under option to Perseus. We believe that the discovery of additional Ore Reserves in trucking distance of existing infrastructure is the most cost effective means available to Perseus of creating value for shareholders. With this objective, further exploration on the nearby tenements will be well funded by Perseus and we are optimistic of discovering further deposits of a similar scale to Nkosuo that will further add to the mine life of the Edikan operation.”

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OVERVIEW OF NKOSUO

Nkosuo is located in Ghana, West Africa, approximately 40 kilometres southwest of the regional town of Obuasi, 200 kilometres west-northwest of the capital Accra and seven kilometres to the north-northwest of Perseus’s Edikan Gold Mine near the town of Ayanfuri.

A Feasibility Study has been completed on the development of mineralisation discovered by Perseus at Nkosuo resulting in the estimation of an Ore Reserve of 332,000 ounces (contained) producing 272,000 ounces (recovered) over three years of mining. All in site costs (AISCs) are expected to be in the range of US$870-US$890 per ounce for Nkosuo.

The area of the Nkosuo Project is underlain principally by Paleoproterozoic Birimian flysch-type metasediments consisting of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Numerous small “Basin-type” or “Cape Coast-type” granite bodies have intruded the sediments along several regional structures.

The Nkosuo Project comprises mineralisation hosted by a single north-northeast striking granitoid body measuring at least 600 metres along strike, typically 250 metres horizontal width and dipping approximately 75 degrees toward west-northwest.

Nkosuo will be mined in a single open pit, with a waste dump located to the west of the pit as shown in Figure 1. Ore from the pit will be trucked on a dedicated haul road to the Edikan processing plant for co-processing with ores from existing Edikan open pits and stockpiles.

Figure 1: Nkosuo Project Layout
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MINERAL RESOURCE ESTIMATES

The Mineral Resource estimates are reported in accordance with the 2012 Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code). The classification categories of Measured, Indicated and Inferred under the JORC Code are equivalent to the CIM categories of the same names (CIM, 2014).

For a comprehensive description of the Nkosuo Mineral Resource estimates, refer to the JORC tables included in Appendix 1. The currently estimated Mineral Resources at Nkosuo are summarised in Table 1 and 2 below.

Table 1: Nkosuo Measured and Indicated Mineral Resources –30 June 2022 ^1,2

Table 2: Nkosuo Inferred Mineral Resources – 30 June 2022 ²

Notes:

1. Indicated Mineral Resources are inclusive of Ore Reserves.
2. Rounding of numbers to appropriate precisions may have resulted in apparent inconsistencies.
3. Based on June 2022 Mineral Resource model constrained to US$1,800/oz pit shell.
0.3g/t gold cut-off applied to in situ material.

GEOLOGY

The Nkosuo project is an addition to the Edikan group of gold deposits that occur near the western flank of the Ashanti Greenstone Belt in south-western Ghana. The regional geology of the Edikan property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts.

Nkosuo is a granite-hosted orogenic gold deposit with structurally controlled mineralisation occurring with disseminated pyrite-arsenopyrite mineralisation associated with quartz veining and sericite alteration within the granite. The surrounding metasedimentary rocks are almost entirely devoid of mineralisation.

The granitoid body at Nkosuo hosting the gold mineralisation strikes north-northeast with an identified length of 600 metres along strike and typically 250 metres in horizontal width that dips 75 degrees towards the west-northwest. Drilling has confirmed that the granitoid body is continuous to at least 350 metres vertical depth below surface. The entire granite is not mineralised throughout but drilling to date indicates substantial zones of gold mineralisation up to 100 metres horizontal width.

DRILLING TECHNIQUES

Nkosuo Mineral Resources are delineated by 222 drill holes for a total of 36,982 metres comprised of reverse circulation (“RC”) and diamond core drill holes drilled by Perseus since 2021. The global Nkosuo Mineral Resource estimates are informed entirely by Perseus drilling with a breakdown by sample type of 43% RC and 57% diamond. This ratio changes for the Mineral Resource constrained within the US$1,800 pit optimisation to 22% RC and 77% diamond. RC drilling used face-sampling hammers with 139-millimetre hole diameter and the diamond core was HQ in the weathered material which changed to NQ2 in the fresh material.

Drill hole collar locations have been surveyed by qualified surveyors. Both RC and diamond core holes were down-hole surveyed at nominal 30 metre intervals.

Orientation of most drill holes at Nkosuo is approximately perpendicular to the strike of mineralisation. Drilling has occurred at 20 metres spacing on 40 metre spaced traverses with holes generally dipping at -55 degrees towards 119 degrees azimuth with partial infill to 20 metres by 20 metres in places. Drill coverage generally extends to about 150 metres vertical depth and to a maximum depth of about 380 metres.

SAMPLING

RC drill samples were collected at drill sites at 1 metre intervals and split using multi-stage riffle splitters. For the majority of Perseus’s drilling, each two consecutive samples were composited into one sample for assaying. Sample weights were nominally 2.5 kilograms and 5 kilograms for 1 metre and 2 metre samples respectively.

Diamond core was sawn in half using a diamond blade saw, with the right-hand half sent for assaying and the left-hand half stored in core trays for reference. Samples were normally taken at 1 metre intervals.

RC drill samples were logged visually for recovery, sample condition (i.e., dry, damp, wet) and contamination. Sample condition logs are available for 96% of RC samples within the mineralised granite. Recovered sample weights are available for 64% of RC samples and RC sample recoveries ranged from an estimated 46% for highly weathered to 80% for fresh material. Diamond core recoveries were measured linearly per drill run. Core recoveries averaged 67% in weathered materials and 98% in fresh rock. There is no indication of a relationship between gold grades and RC/Diamond sample recoveries.

SAMPLE ANALYTICAL METHODS

All sample preparation and assaying was carried out by commercial laboratories; no sample preparation was undertaken by Perseus. Preparation of core and RC samples followed a standard path of drying at 105 degrees Celsius for at least 12 hours, crushing the entire sample to 85% passing -2 millimetres and grinding a 1.5 kilogram split to 85% passing 75 microns. 300gram pulp subsamples are selected by multiple scoop passes.

All RC and diamond core samples have been assayed by 50-gram fire assay with AAS determination by Intertek Testing Services Ghana at their Tarkwa assay laboratory. The technique is considered a total extraction technique

Perseus’s quality assurance and quality control “QAQC” procedures included submission of coarse blanks inserted at 1 in 20, certified reference standards at 1…