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Kavango Resources PLC announced on 20 May 2026 the completion of a metallurgical testwork programme on ore samples from its Hillside Gold Project in Zimbabwe, conducted with Solo Resources, Maelgwyn Mineral Services, and SGS South Africa. The programme defined optimal processing parameters for a 50 tonnes-per-day (tpd) carbon-in-leach gold processing plant and a future capacity upgrade, demonstrating laboratory gold recoveries exceeding 95% and identifying an optimal grind size of 75 microns for various composites.
| Date | 20 May 2026 |
| Time | 07:00:06 |
| Category | Miscellaneous |
| ID | 9895E |
PRESS RELEASE
20 May 2026
KAVANGO RESOURCES PLC
("Kavango" or "the Company")
Hillside Metallurgical Testwork Programme Completed with Highly Positive Results
Kavango Resources plc (LSE:KAV, VFEX:KAV.VX), the Southern Africa-focused metals exploration and gold production company, is pleased to announce the results from a detailed and comprehensive metallurgical testwork programme on ore samples from the Hillside Gold Project ("Hillside"), Zimbabwe. The programme achieved its objective of defining the optimal processing design, processing parameters, and reagent consumption rates for the 50 tonnes-per-day ("tpd") carbon-in-leach ("CIL") gold processing plant at Hillside, and for a future capacity upgrade.
Highlights
· Testwork completed on various blend compositions of Nightshift and Bill's Luck ores demonstrated high metallurgical recoveries of gold within standard processing parameters.
· Very high overall metallurgical recovery of >95% achieved in ideal lab conditions, tested during the optimisation test work. Real-world conditions are expected to deliver in the 90-93% recovery range.
· The Nightshift sample's gold speciation indicated 100% of the gold was native (non-refractory), whilst speciation of the Bill's Luck sample indicated 91% of the gold was in a free milling (native gold and Electrum) form.
· Limited coarse gold detected in the samples tested. Gold species were very fine-grained.
· Very low content of elements that could potentially act as pregnant liquor gold robbers, such as native carbon minerals, and of elements that could potentially lead to high reagent consumption, including copper and zinc.
· Variability test work indicated that a target grind size of 75 microns was optimal for recovery.
· Gravity recovery via centrifugal concentrators ranged from 50% to 90%.
· Gravity gold concentrates can be leached via standard Intensive Leach Reactor ("ILR") technologies with up to 90% recovery after eight hours of leaching time, and 98% recovery after 24 hours of leaching time.
· Required reagent and energy consumption rates to achieve high recoveries are within normal ranges.
Peter Wynter Bee, Interim Chief Executive Officer of Kavango Resources, commented:
"The team is extremely encouraged by these excellent metallurgical testwork results. All processing parameters are considered to be within a normal range, with no excess grinding or reagent consumption requirements. This gives us the confidence to continue building the resource base at our Hillside projects, with the goal of increasing gold production via future increases in processing capacity.
"The information from the testwork will also prove invaluable for optimising and refining the 50 tonnes-per-day plant once it is operational, which is imminent. We would like to thank both Solo Resources and Maelgwyn Mineral Services for their excellent work in completing such a comprehensive and successful testwork programme."
Programme Methodology
Kavango has completed a metallurgical testwork programme in cooperation with Solo Resources ("Solo"), using Maelgwyn Mineral Services ("Maelgwyn"), both based in South Africa. SGS South Africa ("SGS") was subcontracted by Maelgwyn to complete the mineralogical analysis and assessment portion of the scope. SGS is a SANAS-accredited laboratory, and Maelgwyn is an ISO 9001:2015 certified laboratory.
A total of ten samples were utilised in the testwork programme. For further information on sample composition and selection, please see JORC Section 1 at the end of this release.
Composite Blend Methodology
The two main composite blends tested were those deemed to best represent the expected feed material into the two planned processing plants at Hillside:
o 50 tpd plant - currently under construction - Composite D - 50% Bill's Luck Underground High Grade, 50% Bill's Luck Underground Medium Grade.
o Upgrade to 250 tpd - Composite C - 70% Nightshift Fresh Rock, 15% Bill's Luck Underground High Grade, 15% Bill's Luck Underground Medium Grade.
Other plausible feed blends to either of the above plants that were tested included the following:
o Composite A - 50% Nightshift Fresh Rock + 50% Nightshift Oxidised Rock
o Composite B - 100% Bill's Luck (40 % BL high grade, 40% BL medium grade, 20% BL low grade)
o Composite E - 50% Nightshift Fresh Rock, 50% Bill's Luck Fresh Rock (50% BL high grade, 50% BL medium grade)
o Composite F - 100% Bill's Luck (50 % BL low grade, 40% BL medium grade)
o Composite G - 100% Nightshift Oxidised Rock
o Composite H - 100% Nightshift Fresh Rock
Assayed Head Grades
The average head grades assayed from each of the composite blends are shown in the table below:
|
|
Au 1 (g/t) |
Au 2 (g/t) |
Au 3 (g/t) |
Au 4 (g/t) |
Au average (g/t) |
|
Composite A |
1.08 |
0.99 |
1.09 |
|
1.05 |
|
Composite B |
4.17 |
3.33 |
2.93 |
3.78 |
3.55 |
|
Composite C |
3.02 |
2.97 |
3.25 |
|
3.08 |
|
Composite D |
8.15 |
8.42 |
8.21 |
|
8.26 |
|
Composite E |
2.79 |
2.63 |
2.96 |
|
2.79 |
|
Composite F |
2.03 |
2.13 |
2.15 |
|
2.10 |
|
Composite G |
0.48 |
0.55 |
0.55 |
|
0.53 |
|
Composite H |
1.75 |
1.82 |
1.71 |
|
1.76 |
Mineralogical Results
Mineralogical studies were conducted on Bill's Luck and Nightshift ores. The results are very positive with negligible pregnant liquor robbers present (Carbon), and low concentrations of elements that could lead to high reagent consumption (i.e. Copper, Zinc).
The table below shows gold species detected.
|
Gold Mineral |
Bill's Luck (Fresh) |
Nightshift (Oxide) |
|
Native Gold (Au, Ag) |
84.63% |
100.00% |
|
Calverite (AuTe2) |
7.34% |
|
|
Electrum (Au(Ag)) |
6.40% |
|
|
Aurostibite (AuSb2) |
1.16% |
|
|
Petzite (Ag3AuTe2) |
0.48% |
|
|
Total |
100.00% |
100.00% |
The majority of the gold species for both Bill's Luck and Nightshift occur as native gold. The gold species at Nightshift are much finer than at Bill's Luck.
The tables below show the liberation characteristics of the gold species:
|
Liberation by Volume % of gold in host minerals |
Bill's Luck (Fresh) |
Nightshift (Oxide) |
|
Locked (< 30%) |
27.5% |
99.5% |
|
Low Middlings (>=30%, <60%) |
9.2% |
0.3% |
|
High Middlings (>=60%, <90%) |
45.3% |
0.0% |
|
Liberated (>=90%) |
18.0% |
0.5% |
|
Total |
100.00% |
100.00% |
|
Liberation by Exposure % of gold in host minerals |
Bill's Luck (Fresh) |
Nightshift (Oxide) |
|
Locked (<10%) |
25.5% |
98.5% |
|
Partially Exposed (10-30%) |
0.8% |
0.8% |
|
Exposed (30-50%) |
24.4% |
0.2% |
|
Exposed (50-80%) |
31.3% |
0.0% |
|
Exposed (>=80%) |
18.0% |
0.5% |
|
Total |
100.00% |
100.00% |
The gold species at Bill's Luck (in Fresh Rock) are more easily liberated than at Nightshift (in oxide rock).
Total Gold Recovery
Average assayed residue (tailings) grades of 0.14 grammes per tonne ("g/t") and 0.11 g/t gold were recorded for Composites C and D during the kinetic leach tests. These translate to total plant recoveries under ideal laboratory conditions of 97% and 96%, respectively, for Composites C and D.
These results are highly encouraging and represent the ideal recoveries obtained under lab conditions.
Gravity Recoverable Gold (GRG) Testing
Five Stage GRG Tests using a Falcon centrifugal gravity concentrator were conducted on composites A, C, and D to determine GRG % versus different grind sizes. Three Stage GRG Tests using a Falcon centrifugal gravity concentrator were conducted on composites E, F, G, and H to determine GRG % versus different grind sizes and fluidisation pressures.
The results clearly demonstrate the optimal grind size is at P80 = 75 microns for all composites.
Under lab conditions, up to 69% of the gold could be recovered via gravity concentration for Composite A, while Composite C achieved 90% gold recovery via gravity concentration. Composite D achieved a gravity recovery of 87%.
Up to 90% of the gold could be recovered via gravity concentration for Composites E and F, while Composite C achieved 59% gold recovery via gravity concentration, and Composite H achieved a gravity recovery of 50%.
During plant commissioning, fluidisation pressures will be optimised within the ranges tested.
Gravity Concentrate Leach Testing
ILR tests were performed for future reference, should an elution circuit be chosen to be added to the processing plant(s). The testwork showed that 98% of the contained gold in the gravity concentrate leached within a 24-hour period under the intensive leaching conditions.
Leach Testing
Variable Leach Tests were carried out on gravity tails from the Composites to determine optimum conditions.
1. Effect of grind size
Results indicate a clearly positive relationship between decreasing grind size and increasing leaching recovery. The optimal grind size for leaching conditions is P80 = 75 microns.
2. Effect of cyanide addition rate
In all samples tested, gold recovery typically increased as the cyanide addition rate increased. A cyanide addition rate of 0.8 kg/t was selected as the optimal set point, considering the additional cost of higher cyanide dosing rates versus the additional gold dissolution.
3. Effect of pre-oxidation
Tests were conducted on the effect of adding air or oxygen on gold dissolution. The addition of air or oxygen considerably increased the gold dissolution. Atmospheric air addition alone (in the form of injected compressed air into the slurry) increased gold dissolution by an average of 5%. Oxygen addition increased gold dissolution by an average of 10%. Due to the cost, limited availability, and difficulties in transporting pure oxygen in Zimbabwe, it was decided to use hydrogen peroxide as the source of oxygen. Peroxide is added to achieve a 20 parts per million dissolved oxygen in the leach liquor.
4. Effect of leaching time
80% of the gold with Composites C and D was dissolved with four hours of leaching time, with a further 2% dissolved after 20 hours of leaching, and a further 2% beyond that after 24 hours of leaching. The optimum leach residence time was selected at 20 hours.
Gravity tails from Composites E, F, G, and H showed that up to 96.1% of the contained gold could be dissolved for Composite H, and as low as 71.9% for Composite E.
Further information in respect of the Company and its business interests is provided on the Company's website at www.kavangoresources.com and on X at @KavangoRes.
For further information, please contact:
Kavango Resources plc
Peter Wynter Bee
+44 (0) 797 381 8125
Shard Capital (Broker)
Damon Heath/Isabella Pierre
+44 204 530 6926
Inter-Horizon Group
(Sponsoring Broker - Zimbabwe)
Lloyd Mlotshwa
BlytheRay (Financial PR)
Tim Blythe/Megan Ray/Said Izagaren
Tel: +44 207 138 3204
Kavango Competent Person Statement
Craig Hatch
The technical information contained in this announcement pertaining to mining and processing has been compiled by Mr Craig Hatch, a Competent Person and a member of a Recognised Professional Organisation (ROPO). Craig Hatch has sufficient experience that is relevant to the style of mining and type of deposit under consideration and to the activities being proposed to qualify as a Competent Person as defined in the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC 2012). Craig is the Principal Mining Engineer of Minorex Pty Ltd and a consultant to Kavango Resources and is a member of the Australasian Institute of Mining and Metallurgy (AusIMM), a recognised professional organisation.
20 May 2026
JORC Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections.)
|
Criteria |
JORC Code explanation |
Commentary |
|
Sampling techniques |
· Nature and quality of sampling (e.g. cut channels. random chips. or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. |
· Bulk samples of 30-50 kg each were collected by hand for the purposes of completing the metallurgical testwork programme. · At the Nightshift deposit, 4 samples were taken from different artisanal/small scale miner ore piles on the surface that had been recently extracted from their pits. 2 samples taken were representative of oxidized ore, and 2 samples taken were representative of fresh rock ore. · From the Bill's Luck Underground, 6 samples were collected as per the following: · 2 representing low grade ore (>=0.5 g/t, <= 1.0 g/t) · 2 representing medium grade ore (>1.0 g/t, <= 1.5 g/t) · 2 representing high grade ore (> 1.5 g/t) |
|
· Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. |
· Large sample sizes (i.e. >30 kg each) were grabbed from the piles to maximise representativity. · Samples were crushed separately over 2 stages, followed by screening to 100% passing 2 mm. Each sample was then thoroughly blended, followed by cone and quartering into the required portion sizes for the laboratory testing. |
|
|
· Aspects of the determination of mineralisation that are Material to the Public Report. |
||
| · In cases where 'industry standard' work has been done this would be relatively simple (e.g. 'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay'). In other cases, more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (e.g. submarine nodules) may warrant disclosure of detailed information. | ||
|
Drilling techniques |
· Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc). |
· No drilled samples were used for the metallurgical testwork campaign as bulk samples were required, and insufficient representative core and/or RC chip volumes were available. |
|
· Measures taken to maximise sample recovery and ensure representative nature of the samples. |
· The samples taken were of a large enough volume (>30kg each) to be considered representative of the material type and grade they were taken from. |
|
|
· Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
· It was noted by the laboratory that received the samples that they were mostly comprised of coarse rock particles greater than 100 mm. |
|
|
Logging |
· Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation. mining studies and metallurgical studies. |
· The grab samples for the metallurgical testwork were not geologically or geotechnically logged. · The samples were selected from suitable piles to represent their intended classification for the planned composite blends: · Nightshift Open Pit oxide ore · Nightshift Open Pit fresh rock ore · Bill's Luck underground low-grade fresh rock ore · Bill's Luck underground medium grade fresh rock ore · Bill's Luck underground high-grade fresh rock ore |
|
· For all sample types, the nature, quality and appropriateness of the sample preparation techniques. |
· The field samples were bagged and clearly tagged and labelled · The laboratory sample preparation technique is considered appropriate to ensure representativeness and homogeneity after crushing, mixing, and splitting. |
|
|
· Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. |
· Quality control procedures for sampling of output materials during the metallurgical testwork campaign were managed by the laboratory Maelgwyn. |
|
|
· Measures taken to ensure that the sampling is representative of the in-situ material collected, including for instance results for field duplicate/second-half sampling. |
· The bulk grab samples were split by cone and quartering to produce duplicates to ensure sufficient material for the different metallurgical tests conducted. |
|
|
Quality of assay data and laboratory tests |
· The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. |
· No checks were made on Maelgwyn's assaying and laboratory procedures, Maelgwyn is a reputable and ISO certified metallurgical testwork laboratory. |
|
Verification of sampling and assaying |
· The verification of significant intersections by either independent or alternative company personnel. |
· No assay results from the metallurgical testwork programme were verified by a 3rd party. |
|
· Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. |
· Data storage is on a cloud storage facility with access controls and automatic backups. |
|
|
· Discuss any adjustment to assay data. |
· No adjustments were made to assay data. |
|
|
· Whether sample compositing has been applied. |
· Composite samples were made to create plausible mill feed blends into the 50 tpd plant currently under construction, and a future planned 200-250 tpd plant. |
|
|
Sample security |
· The measures taken to ensure sample security. |
· All samples are stored at a secure facility at the field office. · Sample bags are logged, tagged, double bagged and sealed in plastic bags stored at the field office. · Samples are stored in a locked company compound at site and in a locked container in Bulawayo. They are shipped onwards to the analytical facility by a reliable commercial courier. · Sample security includes a chain-of-custody procedure that consists of filling out sample submittal forms that are sent to the laboratory with sample shipments to make certain that all samples are received by the laboratory. · Prepared samples are transported to the analytical laboratory in sealed bags that are accompanied by appropriate paperwork. including the original sample preparation request numbers and chain-of-custody forms. |
|
Audits or reviews |
· The results of any audits or reviews of sampling techniques and data. |
· The CP has visited both site and considered practices and SOPs at both as acceptable. · The CP reviewed all data and spot-checked significant values versus certificates. |