Highlights of
- The maiden MRE for Luanga shows a substantial increase in tonnes and contained metals (Pd, Pt, Rh, Au, Ni) at higher palladium equivalent ("PdEq") grades than the previously reported Historical Estimate (as defined below).
- Indicated Mineral Resource of 73 million tonnes ("Mt") at 1.75 grams per tonne ("g/t") of PdEq for 4.1 million ounces ("Moz") of PdEq.
- Includes 4.6Mt at 1.43 g/t PdEq of Oxide material.
- Additional Inferred Minerals Resources of
118Mt at 1.50 g/t PdEq for a total of 5.7 Moz PdEq.- Includes 10.0Mt at 1.30g/t PdEq of Oxide material.
- MRE includes of 89,500 tonnes of nickel in sulphides in the Indicated category and 104,600 tonnes Inferred.
- 38% of the MRE in the Indicated category and 62% in the Inferred category.
- Recoverable PdEq MRE grades on sulphide ("Fresh Rock") material are calculated based on two extensive phases of laboratory flotation testwork performed by
Bravo (117 flotation tests) and three programs of historical flotation testwork, including two historical pilot plant tests.- Sulphide recovery assumptions (based on these tests): Pt 88%, Pd 80%, Rh 59%, Au 56%, Ni 50%.
- Recoverable PdEq MRE grades on Oxide material are calculated based on two programs of carbon-in-leach and gravimetric testwork performed by
Bravo , which included 31 leaching tests.- Oxide recovery assumptions (based on these tests): Au 94%, Pd 73%, Rh 61%, Pt 24%
- MRE is based on commodity price assumptions using a 10-year trailing averages.
- Relative percentages of each metal by PdEq value contribution to the MRE are estimated at: 43% Pd, 30% Pt, 12% Rh, 12% sulphide Ni, and 3% Au.
- MRE is open at depth along the entire 8.1km of strike of the deposit.
- MRE delineated to an average depth of 200m while drilling has demonstrated that mineralization continues to depths of at least ~350m in those areas tested and is still open.
- Significant potential also exists to increase oxide inventory beyond that in the current MRE.
- Trenching program is only partially completed, with the entire Central Sector yet to be trenched, and some trenches still to be completed in the North and Southwest sectors.
"The delivery of our maiden mineral resource estimate after only 15 months from our IPO is arguably
Resource Classification | Weathering | Average Grades and Contained Metal Estimates | ||||||||||||
Tonnes | Pd Eq | Pd | Pt | Rh | Au | Ni | ||||||||
Mt | g/t | Oz | g/t | Oz | g/t | Oz | g/t | Oz | g/t | Oz | % | Tonnes | ||
Indicated | Oxide | 4.6 | 1.43 | 212,990 | 0.91 | 135,949 | 0,54 | 79,901 | 0.07 | 10,031 | 0,08 | 11,944 | n/a | n/a |
Fresh Rock | 68.5 | 1.77 | 3,892,313 | 0.78 | 1,705,709 | 0.53 | 1,159,078 | 0.06 | 131,248 | 0.07 | 146,263 | 0.13 | 89,539 | |
Total | 73.1 | 1.75 | 4,105,303 | 0.78 | 1,841,658 | 0.53 | 1,238,979 | 0.06 | 141,279 | 0.07 | 158,207 | 0.13 | 89,539 | |
Inferred | Oxide | 10.0 | 1.30 | 418,810 | 0.75 | 241,117 | 0.72 | 230,367 | 0.08 | 25,738 | 0.04 | 12,444 | n/a | n/a |
Fresh Rock | 108.1 | 1.52 | 5,286,970 | 0.60 | 2,082,479 | 0.57 | 1,997,054 | 0.05 | 190,746 | 0.04 | 122,076 | 0.10 | 104,640 | |
Total | 118.1 | 1.50 | 5,705,780 | 0.61 | 2,323,596 | 0.59 | 2,227,421 | 0.06 | 216,484 | 0.04 | 134,520 | 0.10 | 104,640 | |
Table 1: MRE Declaration at a Cut-off of 0.5g/t PdEq* |
* Notes:
- The MRE has been prepared by Porfírio Cabaleiro Rodriguez,
Mining Engineer, BSc (Mine Eng ), MAIG, director of GE21 Consultoria Mineral Ltda., an independent Qualified Person ("QP") under National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101"). The effective date of the MRE is22 October 2023 . - Mineral resources are reported using the 2014 CIM Definition Standards and were estimated in accordance with the CIM 2019 Best Practices Guidelines, as required by NI 43-101.
- Mineral resources that are not mineral reserves do not have demonstrated economic viability. There is no certainty that all mineral resources will be converted into mineral reserves.
- This MRE includes inferred mineral resources which have had insufficient work to classify them as Indicated mineral resources. It is uncertain but reasonably expected that inferred mineral resources could be upgraded to indicated mineral resources with continued exploration.
- The Mineral Resource Estimate is reported/confined within an economic pit shell generated by Whittle software, using the following assumptions:
Generated from work completed by
- Phase 1 and 2 Metallurgy testwork – Metallurgical recovery in sulphide material of 80% Pd, 88% Pt, 59% Rh, 56% Au, 50% Ni to a saleable Ni-PGM concentrate.
- Phase 1 and 2 Metallurgy testwork– Metallurgical recovery in oxide material of 73% Pd, 24% Pt, 61% Rh, 94% Au to a saleable PGM ash residue (Ni not applicable).
- Independent Geotechnical Testwork – Overall pit slopes of 40 degrees in oxide and 50 degrees in Fresh Rock.
- Densities are based on 26,898 relative density sample measurements. Averages are 1.58 t/m3 oxide, 2.71 t/m3 Saprock and 2.85 t/m3 fresh rock.
- External downstream payability has not been included, as the base case MRE assumption considers internal downstream processing.
- Payable royalties of 2%.
Metal Pricing:
- Metal price assumptions are based on 10-year trailing averages: Pd price of
US$1,380 /oz, Pt price ofUS$1,100 /oz, Rh price ofUS$6,200 /oz, Au price ofUS$1,500 /oz, Ni price ofUS$15,648 /t.
- Metal price assumptions are based on 10-year trailing averages: Pd price of
Palladium Equivalent ("PdEq") Calculation:
- The PdEq equation is: PdEq = Pd g/t + F1 + F2 + F3 + F4
Where: F1 = ((Ptp*PtR)/(Pdp*PdR)) x Ptt ; F2 = ((Rhp*RhR)/(Pdp*PdR)) x Rht ; F3 = ((Aup*AuR)/(Pdp*PdR)) x Aut ; F4 = ((Nip*NiR)/(Pdp*PdR)) x Nit;
being P = Metal Price and R = Recovery
Costs are taken from comparable projects in GE21's extensive database of mining operations in
- Mining costs:
US$2.50 /t oxide,US$3.50 /t Fresh Rock. Processing costs:US$8.50 /t fresh rock,US$7.50 /t oxide.US$2.50 /t processed for General & Administration.US$1.00 /t processed for grade control.US$0.50 /t processed for rehabilitation.
- Mining costs:
- Several of these considerations (metallurgical recovery, metal price projections for example) should be regarded as preliminary in nature, and therefore the PdEq calculations should also be regarded as preliminary in nature. Totals may not sum due to rounding.
- The current MRE supersedes and replaces the Historical Estimate (as defined and described below), which should no longer be relied upon.
- The QP is not aware of political, environmental, or other risks that could materially affect the potential development of the Mineral Resources.
The Luanga deposit mineral resource database consists of 394 drillholes (
All historic data used for the MRE has been validated statistically to show no significant bias, either by twinned drillholes, extensive re-sampling of historic drill core, statistical comparison of historical data with
Nine mineralized domains were generated based on the six different styles of mineralization as defined in geological section below (Figure 4). The parent block model (Figures 2 & 3) is 25 m x 25 m x 5 m with 5 m x 5 m x 5 m sub-blocks, with interpolation of elements Multiple Indicator Kriging ("MIK") for each mineralized fresh rock domain and Ordinary Kriging ("OK") for each oxide domain.
There are no known issues that materially affect the MRE other than the usual risks faced by any mining project in
The metallurgical recovery figures achieved at laboratory scale are based on 117 flotation tests in 2 phases, and more than 30 flotation tests undertaken by the previous owner. Continuous mini-pilot testwork is currently ongoing. Oxide recoveries used in the MRE calculation are based on results generated from two programs (2022 and 2023) of carbon-in-leach and gravimetric testwork performed for
Metal price assumptions are derived from the 10-year trailing price averages to smooth out volatility and price cycle movement in each of these metals. For illustration purposes, the pie chart below (Figure 1) shows the relative percentages of metal value contribution to the Luanga MRE using 'grade x metallurgical recovery x metal price' for each metal.
Based on recoveries and GE21's estimates of costs, a cut-off grade ("COG") of 0.44 g/t PdEq was determined, which
A sensitivity analysis of the COG on the MRE, from 0.1 to 1.0 g/t PdEq, in increments of 0.1 g/t is shown in Table 2.
INDICATED | INFERRED | ||||||
PdEq Cut-off grade | Tonnes | Distribution | Recovered Pd/Eq | PdEq Cut-off grade | Tonnes | Distribution | Recovered Pd/Eq |
(g/t) | Mt | ( %) | (g/t) | (g/t) | Mt | ( %) | (g/t) |
0.1 | 81 | 100 % | 1.58 | 0.1 | 135 | 100 % | 1.33 |
0.2 | 81 | 99 % | 1.60 | 0.2 | 134 | 99 % | 1.34 |
0.3 | 79 | 98 % | 1.62 | 0.3 | 132 | 97 % | 1.37 |
0.4 | 77 | 94 % | 1.68 | 0.4 | 126 | 93 % | 1.42 |
0.5 | 73 | 90 % | 1.75 | 0.5 | 118 | 87 % | 1.50 |
0.6 | 69 | 85 % | 1.82 | 0.6 | 108 | 80 % | 1.58 |
0.7 | 64 | 79 % | 1.91 | 0.7 | 97 | 72 % | 1.69 |
0.8 | 59 | 73 % | 2.01 | 0.8 | 88 | 65 % | 1.79 |
0.9 | 55 | 68 % | 2.10 | 0.9 | 80 | 59 % | 1.89 |
1.0 | 51 | 63 % | 2.18 | 1.0 | 73 | 54 % | 1.98 |
Table 2: MRE Sensitivity (grade/tonnes/cut-off) with a 0.5g/t PdEq selected for the base case. |
*Notes: | |
| |
A historical estimate (the "Historical Estimate") prepared internally in 2017 by the prior owner of Luanga indicated a total of "
The Company believes that there is excellent potential to increase this initial MRE at Luanga, as follows:
- The mineralization is open at depth along the entire 8.1km of strike.
- Outside of the Central Sector, the current MRE generally extends to depths that align with the depths of the Phase 1 drilling, typically around 200 metres in the Southwest and North Sectors. This can be seen in Figure 2, where there are few drill holes that extend below the constraining pit shell. Drilling in the Phase 1 (completed) program targeted the depth extent of historical drilling (typically up to ~150m), while the ongoing Phase 2 and 3 programs aim to test the extensions of mineralization to 300+m below surface. To date, only the Central Sector drilling reached depths of ~300m below surface (Figure 4). The cross-section in Figure 5 (Southwest Sector) shows how the lack of data at depth is restricting the MRE. Similarly, in Figure 3, the interpreted continuation of mineralization at depth (unclassified, coloured grey) demonstrates where deeper drilling is required.
- Several deeper Phase 2 drill holes completed by
Bravo in the Central Sector have intersected wider and higher-grade mineralization intervals than typical of the MRE, such as hole DDH23LU175 which reported 54.2m at 3.33g/t PGM+Au, 0.22% Ni from 280.5m, including 32.5m at 4.99g/t PGM+Au, 0.30% Ni from 300.2m (see News Release15 August 2023 ). This could indicate potential for higher grades and greater widths of mineralization below the limit of the current MRE, with potential for additional tonnage. Bravo's trenching program is only partially complete, with the entire Central Sector yet to be trenched and some trenches still to be completed in the North and Southwest Sectors. Nevertheless, where completed, trenching indicates a potential for greater aerial extent and typically higher grades (see News Releases08 May 2023 and26 September 2023 ) of oxide mineralization (likely due to supergene enrichment and more extensive surface dispersion). As a result, the current MRE shows a limited extent and lower grades in oxides in areas where no trenching has been completed versus those areas where trenching has been completed.Bravo plans to complete trenching over the entire strike length of the Luanga deposit over the next 6 months and, if recent trends continue,Bravo could expect to see increased tonnes and grade in the oxides versus those within the current MRE. Additionally, trenching to date has identified the presence of high-grade zones within the oxide, which could be studied in later phases as well.- Some of
Bravo's deeper drilling has intersected several mineralized horizons stratigraphically above or below the main mineralized horizon, which is known as theMain Sulphide Zone ("MSZ"). However, many historic holes and several ofBravo's earlier drill holes did not extend deep enough to adequately test these horizons (Figure 5). As a result, they are relatively minor contributors to the current MRE. AsBravo continues its deeper drilling and re-enters earlier holes to deepen them, these poorly defined mineralized zones may develop into more significant contributors to future MRE growth.
Porfírio Cabaleiro Rodriguez,
An independent peer review was carried out by Anderson Candido FAusIMM (
Technical assurance was carried out by Professor Mark Noppé MAICD, FAusIMM (CP). Prof. Noppé is the Director of the
Each of
Technical information in this news release has also been reviewed and approved by
Details of the MRE will be provided in a technical report with an effective date of
This news release contains forward-looking information which is not comprised of historical facts. Forward-looking information is characterized by words or sentences such as "potential", "potentially", "prospective", "assume", "assumptions", "preliminary", "if", "generally", "expect", "expected", "reasonable expectation", "indicate", "believe", "anticipate", "probable", "probability", "plans" variants of these words and other similar words, phrases, or statements that certain events or conditions "could", "may", "should" or "will" occur. This news release contains forward-looking information pertaining to the Company's maiden MRE; the potential for future MRE growth from deeper drilling, and/or additional zones and/or drilling of geophysical targets; potential repeatability and improvements to the economic assumptions and/or to metallurgical recoveries used in the MRE; and the Company's plans in respect thereof. Forward-looking information involves risks, uncertainties and other factors that could cause actual events, results, and opportunities to differ materially from those expressed or implied by such forward-looking information. Factors that could cause actual results to differ materially from such forward-looking information include, but are not limited to, unexpected results from exploration programs, changes in the state of equity and debt markets, fluctuations in commodity prices, delays in obtaining required regulatory or governmental approvals, environmental risks, limitations on insurance coverage; and other risks and uncertainties involved in the mineral exploration and development industry. Forward-looking information in this news release is based on the opinions and assumptions of management considered reasonable as of the date hereof, including, but not limited to, the assumption that the assay results confirm that the interpreted mineralization contains significant values of nickel, PGMs and Au; that the mineralization remains open to depth; that Ni grades are improving to depth; that future drill and assay results will be in line with management's expectations; that exploration and other business activities will not be adversely disrupted or impeded by regulatory, political, community, economic, environmental and/or healthy and safety risks; that the Luanga project will not be materially affected by potential supply chain disruptions; and general business and economic conditions will not change in a materially adverse manner. Although the Company believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information. The Company disclaims any intention or obligation to update or revise any forward-looking information, other than as required by applicable securities laws.
This press release contains information relating to the Historical Estimate. No qualified person (as defined in NI 43-101) has done sufficient work to classify the Historical Estimate as current mineral resources or mineral reserves under NI 43-101 and
This news release has been prepared in accordance with the requirements of the securities laws in effect in
Schedule 1: Schedule: Key Assumptions and Methods Used for the Mineral Resource Estimate
Variography and Interpolations
Grade estimation for sulphide material was completed using the MIK technique, for each element and for each domain. Ten grade increments levels were used to define indicators for each element. Variography and MIK were performed using Isatis.neo software and reported for each respective domain. No grade variables were capped. Grade estimation for oxide material was completed using the OK technique, for each element and for each domain.
The PdEq COG of 0.5 g/t was calculated by taking the all-in cost (oxide and fresh rock) and dividing them by the value of one gram of Pd multiplied by metallurgical recovery. From this a global average (rounded up from the calculated value of 0.44g/t) of 0.5 g/t PdEq has been chosen as the COG. Rounding to 0.5g/t adds a further >10% contingency to the calculation process to accommodate potential future changes in any, or several of, the assumptions.
COG (PdEq) | ||
Oxide | Units | |
Costs | 14.0 | US$/t |
DGV1 | 31.95 | US$/g |
Cut-Off | 0.43 | PdEq/ g/t |
Fresh | Units | |
Costs | 16.0 | US$/t |
DGV1 | 35.5 | US$/g |
Cut-Off | 0.44 | PdEq/ g/t |
Avg Cut-off | 0.5 | PdEq/ g/t |
1 Deposit Grade Value ("DGV") = (P-Pd/31.1035) * R-Pd | |
Where: P-Pd = Palladium Price in US$/oz, | |
R-Pd = Palladium Metallurgical Recovery |
To classify mineral resources, a study of spatial continuity for PdEq was conducted using variography followed by ordinary kriging interpolation. This study established a continuity zone suitable for considering as "Indicated Mineral Resources", with a drilling grid of approximately 75m x 75m, extending both along the strike and dip directions, and requiring a minimum of two drill holes. Subsequently, manual post-processing was undertaken to construct wireframes representing the volumes categorized as Indicated, while considering the blocks within the resource pit shell. Any remaining blocks within the resource-limiting pit were classified as "Inferred Mineral Resources".
The reported MRE is pit constrained using Whittle software to create a pit shell that has reasonable prospects for eventual economic extraction. Relevant parameters used in the mineral resource estimate are shown below the MRE table and include commodity prices used, metallurgical recoveries, geotechnical assumptions, and cost structures. Further, there are no known environmental or community matters that are likely to constrain the future extraction of the reported MRE.
Metallurgical recoveries used in the MRE calculation are as follows:
- Sulphide (Fresh rock) recovery inputs: Pt 88%, Pd 80%, Rh 59%, Au 56%, Ni 50%
- Oxide recovery inputs: Au 94%, Pd 73%, Rh 61%, Pt 24%.
Fresh rock recoveries used in the MRE calculation are based on results generated from two extensive phases of laboratory flotation testwork performed by
- Identification and application of fines flotation regimes demonstrating a material improvement of +6% on rougher recoveries while maintaining concentrate grade. Further cleaner improvement is anticipated from planned testing.
- Optimization of flowsheet and reagent suite, resulting in significant selectivity and recovery improvement at the rougher stage, and the production of high-grade concentrates, which provides potential for blending and concentrate quality optimization.
Oxide recoveries used in the MRE calculation are based on results generated from two programs (2022 and 2023) of carbon-in-leach and gravimetric testwork performed for
The conceptual oxide processing flowsheet has been validated at each processing stage through testwork, including: PGM solubility in the presence of cyanide at ambient temperature/pressure and within reasonable reagent dosage conditions; PGM adsorption onto carbon; Final product generation as saleable high grade PGM ash residue ("ashing" or "ashed" is the burning of the loaded carbon for final mass reduction to an ultra-high grade ash residue) with an assayed average grade of 119,100g/t PGM (or 11.91% PGM).
- Intense host rock weathering in oxide and a high degree of naturally liberated PGM, contributing to lower mining and comminution costs.
- High degree of solubility in cyanide, particularly for Au, Pd and Rh.
- High PGM absorption kinetics and recovery for PGM onto carbon.
Details of the 2022 and 2023 metallurgical programs and their results will be documented in the Technical Report (effective date of
Luanga is a layered mafic-ultramafic complex consisting of a 6km across (on surface) and up to 3.5km wide ovoid-shaped intrusion, which hosts 8.1km (strike length) of mineralization. Today, the
The UZ is up to 800m thick and consists of harzburgites with lesser dunites and lenses of orthopyroxenite in the upper portions (facing criteria, considering the overturned sequence). The lower contact of the UZ with the
The TZ is up to 1,000m thick, comprised of interlayered ultramafic and mafic cumulate rocks. Interlayering of different rock types in different scales (from centimetres to dozens of metres) is a distinctive feature of the TZ. Cumulate rocks have variable textures, from adcumulate to orthocumulate, and variable assemblages of cumulus and intercumulus minerals. The most common rock types are orthopyroxenite locally with chromite-rich zones/chromitite layers and minor norite/harzburgite layers. Orthopyroxenite is a medium to coarse-grained orthopyroxene cumulate. The texture varies from adcumulate to mesocumulate and orthocumulate with plagioclase as the predominant intercumulus mineral. Primary textures and minerals are variably altered to fine-grained aggregates. Chromitite layers with variable thickness and textures occur mainly in the upper portions of the TZ and the lowermost portion of the MZ. The thickest chromitite-rich layer is up to 60cm, located at the contact between the upper harzburgite and orthopyroxenite layers of the TZ.
The MZ is up to 3,000m thick, comprised of mostly monotonous norites. The norite consists of medium-grained orthopyroxene + plagioclase cumulates. Primary textures and minerals are variably altered to fine-grained aggregates. Minor interlayered ultramafic rocks in the MZ consist mainly of orthopyroxenites.
The Luanga mineralized envelope follows the arc-shaped structure of the mafic-ultramafic complex along a strike of approximately 8.1 km, which is then subdivided into three mineralized sectors named North, Central and Southwest. The TZ at Luanga hosts several PGM mineralized units, including the
The proposed genetic model for PGM mineralization considers: (i) the magmatic evolution of the complex; (ii) the petrographic and geochemical differences of mineralization styles; (iii) the PGM assemblages. The mineralization stages are summarized as follows:
- Stage 1 – Early segregation and precipitation of the High PGM low Rh (Pd-Pt), and High Ni-Rh sulphide zones during the crystallization of olivine cumulates in the UZ.
- Stage 2 – The crystallization of olivine cumulates in the UZ with minor crystallization of sulphide minerals progressively upgrading the sulphur content of the residual magma. The TZ marks an abrupt change in the dynamics of the magma chamber, characterized by cyclic units. Sulphur saturation is triggered, and the MSZ PGM-rich layer is precipitated.
- Stage 3 – Periodic magma influxes with continuous segregation from the base metal sulphide liquid and precipitation of Low Sulphide – High PGM zone, in similar conditions to the MSZ.
- Stage 4 – Alteration promotes sulphur loss and PGMs are combined with other elements (As, Sb, Te, Sn and Bi) and form PGM Low Sulphur mineralization. Precipitation of the
Massive Sulphide Zone ("MASU") as a product of a late hydrothermal-magmatic event controlled by local shear zones.
Based on the magmatic evolution of the complex and mineral assemblages, supported by petrographic/chemistry studies, six different styles of mineralization have been identified within Luanga to date, described as follows:
(i) | High Pd-Pt, low Rh-Au-Ni mineralization. | ||
(ii) | High Ni-Rh, low Pd-Pt-Au mineralization. | ||
(iii) | High Pd>Pt, +/- Rh-Au-Ni mineralization (the MSZ, which represents the substantial majority of the tonnage contained in the MRE). | ||
(iv) | High Pt>Pd, low Rh-Au-Ni mineralization associated with sulphide-poor layers. | ||
(v) | High Pt-Rh, +/- Pd, with low Ni mineralization related to chromitite-rich layers. | ||
(vi) | High Pd>Pt + high Ni-Cu, low Rh-Au mineralization associated with massive sulphide layers or zones. |
The known mineralized system being evaluated by
Samples follow a chain of custody between collection, processing, and delivery to the SGS laboratory in Parauapebas, state of Pará,
QAQC is maintained internally at the laboratory through rigorous use of internal certified reference materials ("CRM"), blanks, and duplicates. An additional QAQC program is administered by
Bravo SGS Geosol | ||||||
Preparation | Method | Method | Method | Method | ||
For All Elements | Pt, Pd, Au | Rh | Sulphide Ni, u | Trace Elements | ||
PRPCLI (85% at 200#) | FAI515 | FAI30V | AA04B | ICP40B | ||
Bravo ALS | ||||||
Preparation | Method | Method | Method | Method | ||
For All Elements | Pt, Pd, Au | Rh | Ni-Sulphide | Trace Elements | ||
PREP-31B | PGM-P27 | Rh-S25 | Ni-ICP05 | ME-ICP61 | ||
Historic Drill Assaying SGS Geosol | ||||||
Preparation | Method | Method | Method | Method | ||
For All Elements | Pt, Pd, Au | Rh | TOTAL Ni | Trace Elements | ||
Crushed to <200 mesh | FA30A | FA30B | ICP-117 | ICP-117 |
SOURCE
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