Robex Reports a Feasibility Study for Kiniero With Significantly Improved Economics vs PFS
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QUBEC CITY, June 14, 2023 (GLOBE NEWSWIRE) -- Robex Resources Inc. (Robex or the Company) (TSXV: RBX) is pleased to announce the results of the feasibility study (the FS, Feasibility Study or the Study) for the Kiniero Gold Project (the Kiniero Gold Project, or the Project) in Conakry, Guinea. The FS was prepared in accordance with Canadian Securities Administrators National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101).
The independent NI 43-101 technical report supporting the Kiniero Gold Project Feasibility Study will be published on SEDAR at www.sedar.com within the next 45 days.
HIGHLIGHTS:
- Improved economics: 26% increase in pre-tax Net Present Value 5% (NPV5%) to US$251m and Internal Return Rate (IRR) of 42% at a base case gold price of US$1,650/oz while post-tax NPV5% stands at US$ 170m and IRR at 31%;
- Increased Life of Mine (LoM): Mineral Reserves increased by 165koz or 21% to 968koz from the Pre-Feasibility Study (PFS), increasing LoM to 9.5-years (46% up compared to PFS);
- Lower costs: LoM All-In Sustaining Costs (AISC) below initial target of US$ 1,000/oz, at US$ 980/oz, improving from PFS (US$ 1,035/oz);
- Lower strip ratio: LoM Strip Ratio of 2.8:1, from 4.4:1 in the PFS; and
- Significant potential beyond Mineral Reserve life in FS: Indicated Mineral Resources (inclusive of Mineral Reserves) at 1,481koz @ 1.07g/t, along with Inferred Mineral Resources of 1,090koz@ 1.19g/t effective November 12, 2022;
Table 1: Significant improvement from PFS results
| Based on a US$ 1,650/oz gold price | Units | PFS | FS | Variation |
| Probable Mineral Reserves (incl. legacy stockpiles) | koz | 803 | 968 | +21% |
| LoM | Year | 6.5 | 9.5 | +46% |
| Average annual production LoM | koz | 110 | 90 | -18% |
| Initial capital from 01/01/23 | US$m | 144 | 160** | +11% |
| LoM AISC | US$/oz | 1,035 | 980 | -5% |
| Pre-tax NPV5%* | US$m | 199 | 251 | +26% |
| Pre-tax IRR, % | % | 49% | 42% | -7pts |
| After-tax NPV5% | US$m | 115 | 170 | +48% |
| After-tax IRR, % | % | 32% | 31% | -1pts |
*NPV in the PFS calculated as of 01/01/2023 while the NPV in FS calculated as of 01/07/2023
**Including initial capex expected to be paid from January 1, 2023 to June 30, 2023
Update on Construction Activities
Construction of the project started in Q4 2022, with US$ 27m expected to be spent by June 30, 2023 of the initial capital costs of US$160m (or 17% of total):
- Contractors mobilized on site and detailed engineering is ongoing;
- In line with the previously disclosed mandate with Taurus Mining Finance Fund No. 2, L.P. (Taurus), we are currently discussing the terms of the Project Finance Facility and providing information needed for due diligence. Please see the press releases dated January 24, 2023 and March 21, 2023 available on SEDAR at www.sedar.com for further details;
- Resource expansion program ongoing, the last drill hole in the geological database supporting the FS dates from August, 17, 2022 with 24,443m of drilling completed since then; and
- Exploration is underway at our Mankan target in the north portion of the property for the first time since the project was owned by SEMAFO.
Aurlien Bonneviot, CEO of Robex commented: The completion of the FS for the Kiniero Gold Project is a major milestone in our journey towards project development, as the FS optimizations and updated Mineral Resource Estimate result in a stronger project with enhanced economics.
Since the announcement of the Kiniero acquisition on 20 April 2022, we have improved the asset to reach a now-projected 9.5-year LoM. Kiniero is now expected to average above 100koz per annum over the first 7 years and we will continue to drill to hopefully increase the average grade, the production capacity and the LoM.
This FS incorporates the actual pricing and tenders we have been collecting for the construction, giving us confidence in the upfront capex estimates. The majority of the parameters are at the detailed design stage, the construction crew has mobilized on site, and we are on track for the first gold poured in mid-2024.
While the FS includes a 21% increase in Mineral Reserves, this represents only a fraction of the total Mineral Resource, and we are targeting additional conversions of Mineral Resources to Mineral Reserves in the coming years. With more than 1moz of Inferred Mineral Resources within 10 km of the processing plant, we see potential for significant LoM extensions and rapid growth at the asset in a short timeframe.
With these excellent results, Robex will focus its efforts on the previously announced debt package with Taurus Mining Finance Fund No. 2, L.P..1
1 Forward-looking statement. See the Forward-Looking Information and Forward-Looking Statements section of this press release
Feasibility Study Highlights
The ore mined from the Kiniero deposit is expected to be processed through a standard 3.0mt capacity Carbon-in Leach/Gravity (CIL) plant. The mine is expected to be an open pit using conventional mining methods.
Table 2: Kiniero FS Highlights
| Units | Value | |
| Plant, size and CAPEX | ||
| Plant capacity | Mt | 3.0 |
| Upfront capital from January 1, 2023 | US$m | 160 |
| Mineral Reserves and Resources (incl. legacy stockpiles) | ||
| Probable Mineral Reserves | koz | 968 |
| Indicated Resources (incl. Reserves) | koz | 1,481 |
| Inferred Resources | koz | 1,090 |
| Mining Operations | ||
| LoM total ore tonnes mined | kt | 81,715 |
| LoM waste tonnes mined | kt | 60,304 |
| LoM ore tonnes mined ex pit | kt | 21,410 |
| Average grade mined | g/t Au | 1.27 |
| LoM strip ratio | W:O | 2.8 |
| Processing Operations | ||
| LoM tonnage processed | kt | 27,665 |
| Average grade processed | g/t Au | 1.09 g/t |
| Average recovery LoM | % | 87.2 % |
| Production and Costs Summary | ||
| LoM production | koz/Au | 851 |
| Average first three years of production pa | koz/Au | 105 |
| Average LoM production pa | koz/Au | 90 |
| AISC | US$/oz | 980 |
Table 3: Kiniero Project Gold Price Sensitivity (Base Case and RPEEE*) as of July 1, 2023
| Units | US$ 1,650/oz (Base Case) | US$ 1,950/oz (RPEEE gold price) | |
| Pre-tax returns | |||
| NPV5% | US$m | 251 | 437 |
| IRR | % | 42 % | 65 % |
| Payback period | year | 3.4 | 2.7 |
| Post-tax returns | |||
| NPV5% | US$m | 170 | 301 |
| IRR | % | 31 % | 48 % |
| Payback period | year | 4.3 | 3.2 |
*Reasonable Prospects for Eventual Economic Extraction (RPEEE) or gold price used for Mineral Resources.
As shown in Figure 1: Gold Production and AISC Summary across the LoM below, the Study demonstrates Kinieros ability to deliver an average of 90koz of gold per year at an AISC of US$ 980/oz over the LoM, as mine plan optimization efforts prioritized a stable, long mine life, rather than peak upfront production. Over the coming years, Robex intends to continue its exploration efforts to continue to extend the LoM and increase annual production.
Figure 1: Gold Production and AISC Summary across the LoM
FEASIBILITY STUDY DETAILS
Overview
The Project is located in eastern Guinea in the Kouroussa Prefecture. It is situated approximately 27km southeast of the town of Kouroussa and at a distance of 546km from Conakry, the capital of Guinea (Figure 2: Regional Locality of the Kiniero Gold Project and Regional Infrastructure of Guinea).
The Kiniero Gold Project is a 470.48km exploitation and exploration land package that consists of the adjoining Kiniero exploitation License Area and Mansounia exploitation License Area. The Kiniero Project is one of the largest gold licences in Guinea.
Figure 2: Regional Locality of the Kiniero Gold Project and Regional Infrastructure of Guinea
Kiniero gold deposits, located in the prolific gold-producing Siguiri Basin, were discovered in the early 1900s and were subsequently explored until 2002 when gold production began under the ownership of Semafo Inc and its subsidiary Semafo Guine SA.
The historical Kiniero gold mine comprised an open pit mining operation that produced 418,000 ounces of gold during its 12-year operational history. The mine was placed on care and maintenance in early 2014.
Robex is now restarting the Kiniero gold mine as a long-life open pit mining operation based on constructing a new 3Mtpa process plant.
Given the strong exploration potential,a combination of near plant brownfields infill and known extension, as well as greenfield large-scale targets, Robexis targeting (i) the discovery of Mineral Resources across the Kiniero exploration permit area over the next few years, and (ii) the conversion of Mineral Resources into Mineral Reserves.
An extensive drilling programme is ongoing on the numerous identified deposits to increase the resource base and extend the LoM at Kiniero predominately through extending the drilling density at depth and along known strike extensions.
Since the beginning of the construction, Robex has been committed to involve village communities in the mine's development, as well as exploring sustainable power energy source to reduce and limit its environmental footprint.
Geology
The property is located within the Kiniero Gold District of the Siguiri Basin, which is situated in north-eastern Guinea, extending into central Mali. Geologically, the Siguiri Basin comprises a portion of the West Africa Birimian Greenstone Belt, including intrusive volcanics (ultramafics to intermediate) and sediments largely deposited through the period 2.13 Ga to 2.07 Ga.
The volcanic and sedimentary lithologies comprise fine-grained sedimentary rocks (shales and siltstones), with some intercalated volcanic rocks. Sandstone-greywacke tectonic corridors have been preferentially altered and locally silicified, supporting extensive brittle fracture networks. These in turn have provided host environments for ascending mineralized hydrothermal fluids.
The deposits located on the property are associated with the Proterozoic Birimian orogeny of West Africa. Most gold mineralization in the West African Craton is shear-zone-hosted and structurally controlled, with lithology having a minor, local influence. The mineralization developed in the Kiniero Gold District conforms to this general style of mineralization.
A total of 47 gold anomalies have been identified on the property, of which five clusters of deposits (Sabali, Mansounia, SGA, Jean, and Balan) have been explored sufficiently to enable the estimation of Mineral Resources.
Figure 3: Location of the main Kiniero deposits and cross sections (A-B, C-D) and Figure 4: Cross sections through the SGA (A-B) and Sabali South (C-D) deposits illustrate the location of the main Kiniero deposits and cross sections through the SGA and Sabali South deposits. The selected cross sections display the 0.3g/t gold grade shell, Pit and RPEEE (Reasonable Prospects for Eventual Economic Extraction) Shells, significant gold intercepts (minimum of 2m @ 0.5g/t), and regolith profiles across each deposit. Section A-B, across SGA, demonstrates the deposit's significant northeast strike and depth extension. Section C-D, across Sabali South, shows the deposit's deep weathering saprolite and saprock profile in the east (beyond 100m in areas).
Figure 3: Location of the main Kiniero deposits and cross sections (A-B, C-D)
Figure 4: Cross sections through the SGA (A-B) and Sabali South (C-D) deposits
Mineral Reserves and Resources
The FS is based on the updated Mineral Resources Estimate, as shown in table below, which has a resource-to-reserve conversion ratio for the in-situ estimate of 68%. The Mineral Resource Estimate includes the Mineral Reserves.
Table 4: Mineral Reserves and Resources Summary
| 100% basis | Tonnage (Mt) | Grade (Au g/t) | Content (koz) |
| Probable Mineral Reserves (in-situ) | 21.41 | 1.27 | 872 |
| Probable Mineral Reserves (Legacy Stockpiles) | 6.26 | 0.48 | 96 |
| Total Probable Mineral Reserves | 27.67 | 1.09 | 968 |
| Indicated Mineral Resources (in-situ) | 31.59 | 1.32 | 1,342 |
| Indicated (Legacy Stockpiles) | 11.61 | 0.37 | 139 |
| Total Indicated Mineral Resources (incl. of. Mineral Reserves) | 43.20 | 1.07 | 1,481 |
| Inferred Mineral Resources | 28.61 | 1.19 | 1,090 |
Notes:
- The effective date of the Mineral Reserves is June 1, 2023.
- The effective date of the Mineral Resource estimate is November 12, 2022.
- The date of closure for the sample database informing the in situ Mineral Resources is August 17, 2022. The date of database closure for the stockpiles is November 12, 2022.
- Mineral Reserves are estimated using a long-term gold price of USD1,650 per troy oz for all mining areas while open pit Mineral Resources have been constrained using conceptual open pits based on a gold price of 1,950 US$/oz.
- Mineral Reserves are stated in terms of delivered tonnes and grade before process recovery.
- Mineral Reserves are defined by pit optimization and are based on variable break-even cut-offs as generated by process destination and metallurgical recoveries.
- Metal recoveries are variable and dependent on material type and mining area.
- Open-pit dilution and geological ore loss are applied through the application of 1 m dilution skins to the resource block model using Mining Shape Optimiser (MSO).
- The Qualified Persons, as defined in NI 43-101, responsible for these items of the Technical Report are not aware of any mining, metallurgical, infrastructure, permitting, or other relevant factors that could materially affect the Mineral Reserve estimates.
- The identified Mineral Reserves and Resources are classified according to the Definition Standards on Mineral Resources and Mineral Reserves adopted by the Canadian Institute of Mining Metallurgy and Petroleum and incorporated into NI 43-101.
- Mining recovery of 99% applied to diluted open-pit inventories to account for operational losses.
- The updated Mineral Resource estimate was prepared by Mr Ingvar Kircher who is a Qualified Person as defined in NI 43-101 and who does not or did not have at the relevant time an affiliation with Robex or its subsidiaries, except that of independent consultant/client relationship.
- Cut-off grades for Mineral Resource reporting are:
- SGA, Jean and Banfara: laterite 0.5g/t Au, saprolite (oxide) 0.3 g/t Au, saprock (transition) 0.5g/t Au, fresh 0.6g/t Au.
- Sabali South: laterite 0.5g/t Au, saprolite (oxide) 0.3 g/t Au, saprock (transition) 0.7g/t Au, fresh 0.9g/t Au.
- Sabali North and Central: laterite 0.5g/t Au, saprolite (oxide) 0.3 g/t Au, saprock (transition) 0.9g/t Au, fresh 0.8g/t Au.
- West Balan: laterite 0.5g/t Au, saprolite (oxide) 0.4 g/t Au, saprock (transition) 0.5g/t Au, fresh 0.6g/t Au.
- Stockpiles reported as Mineral Resources have been limited to those dumps which exhibit an average grade >0.3g/t Au.
- Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
- The estimates may be materially affected by environmental, permitting, legal, marketing, or other relevant issues. Please see Forward Looking Statements below and the technical report for the Kiniero Gold Project that will be prepared in accordance with NI 43-101 and filed on SEDAR R at www.sedar.com within the next 45 day.
- Tonnage and grade measurements are in metric units. Contained Au is reported as troy ounces.
- Totals may not compute exactly due to rounding.
Exploration
The Kiniero Projects 2023 planned exploration programme includes a combination of brown and greenfields exploration activities. Greenfields activities comprise the continuation of the license-wide soil geochemistry (BLEG) programme, focussed on completing the Northern Block area of the Kiniero License. In addition, a maiden RC drilling campaign in the Northern Block is planned to target the Mankan, Heriko and Filon Bleu deposits. The drilling will build on the exploration data already generated by SMG and historical drilling completed by Semafo to further delineate the deposits.
Brownfields explorationwill consist of trenching and drilling at and around the near-mine deposits. Drilling will be a combination of diamond and RC drilling and the purpose is twofold, namely Resource addition and Resource to Reserve conversion. Drilling will focus on four deposits: SGA, NEGD, Sabali South and Mansounia Central. SGA, NEGD and Sabali South will comprise Resource addition drilling by strike and depth extension, as well as Reserve conversion drilling. A grid drilling programme at Mansounia Central is designed to further delineate and upgrade the Resource.
A planned total of approximately 5,000m of diamond and 65,000m of RC drilling will be completed at the various deposits. However, the drilling programme will be an iterative process based on the ongoing results and the impact thereof. As a result, the plan may be changed and adapted to any changes in strategy.
Mining Operations
Mining at Kiniero is expected to be undertaken by conventional contractor-operated truck and excavator open-pit mining in the SGA, Jean, SGD, Sabali South, and Sabali North and Central pits using Komatsu PC1250-sized excavators mining on 5 m benches and 2.5m flitches loading 55 t Volvo A60H haul trucks.
Mining in upper oxide layers will be free-dig with drill-and-blast required in areas that mine through the transitional material into fresh rock. The free-dig nature of the oxide and transitional zones has been confirmed by extensive previous mining at the site. Drill-and-blast will be required for approximately 1% of the oxide material, 40% of the laterite, 60% of the transitional, and 100% of the fresh.
Ore will be categorized by material and grade through in-pit grade control and will be hauled to the mine ore pad (MOP). Waste will be hauled to the nearest available waste dump by the Volvo A60H fleet.
Historic mining in Jean, SGA, and SGD has resulted in pit lakes that require dewatering and clean-up before mining.
The key mining infrastructure including pits, waste dumps, stockpiles, and haulage roads is shown in Figure 5: Key Mining Infrastructure Layout.
Figure 5: Key Mining Infrastructure Layout