7th APRIL 2020
OKLO'S POSITIVE METALLURGICAL RESULTS
HIGHLIGHT SIMPLE PROCESSING OPTIONS FOR SEKO
Oklo Resources Limited ("Oklo" or "the Company") is pleased to announce results from the metallurgical test work program completed on samples from Seko within the Company's flagship Dandoko project located in west Mali, Africa.
The program included gravity separation, bond abrasion & mill work indices, leach kinetics and basic grind size variability, and initial flotation test work on three composite samples collected from SK2, representing soft oxide, transitional and fresh/hard rock gold mineralisation.
The test work was undertaken by ALS Metallurgy in Perth, Western Australia under the supervision of Lycopodium Minerals.
HIGHLIGHTS
- Seko exhibits straightforward, non-refractory metallurgical characteristics from the test work completed to date, with a likely processing route incorporating a simple, industry standard cyanide leach circuit.
- Cyanide leach gold recoveries of ~94% for oxide, with ~85% and ~88% gold recoveries for transitional and fresh mineralisation respectively.
- Encouraging leach kinetics and rapid leach times, with at least 96% of extractable gold dissolution within 8 hours.
- Oxide mineralisation amenable to gravity concentration to recover free gold within the milling circuit.
- Flotation gold recoveries to concentrate of ~95% and ~91% for transitional and fresh mineralisation respectively.
- Ball mill work indices of 10.2 kWh/t - 16.0 kWh/t, comparable to other gold operations in the region.
- Moderate bond abrasion index (Ai) for oxide and fresh mineralisation of 0.05 Ai and 0.20 Ai respectively, and 0.31 Ai for transitional mineralisation.
- Further test work to be conducted on samples from SK1 and SK3.
- All metallurgical results to be incorporated into a Scoping Study, to commence following delivery of the Company's maiden Mineral Resource estimate (MRE).
"The metallurgical test work results are highly encouraging in confirming the likelihood of a simple gold processing flowsheet at Seko. The results for the oxide zone, which comprises a large proportion of the mineralisation intersected to date at Seko, are particularly favourable. The test work results complement the excellent progress that the Company is making with its resource definition drilling program at the SK1 North discovery, both of which will be essential elements in informing the forthcoming Scoping Study." - commented Oklo's Managing Director, Simon Taylor.
7th APRIL 2020
SEKO METALLURGICAL TEST WORK PROGRAM
A detailed metallurgical program has been completed at the Company's Seko prospect, following on from previous positive preliminary results. The test work was undertaken on three separate metallurgical samples, representing soft oxide mineralisation grading approximately 4.0g/t gold, transitional mineralisation of approximately 6.5g/t gold and a fresh/hard rock mineralisation grading approximately 3.0g/t gold.
The test work program was undertaken by ALS Metallurgy in Perth, Western Australia under the supervision of Lycopodium Minerals in Brisbane, Queensland.
The scope of the test work program included:
- Physical characterisation test work (bond abrasion and mill work indices).
- Leach kinetics and grind size investigation.
- Flotation tests.
- Gravity recovery test work.
The test work program was designed to provide preliminary comminution design data, gravity recovery data and flotation information suitable for use in the forthcoming Scoping Study. The results will provide key data to assist in identifying the likely processing route for Seko.
SAMPLE SELECTION
Three 80kg composite samples were collected from the SK2 prospect being the central trend at Seko. The oxide and transitional samples were taken from ½ PQ diamond core in hole DDSK19-047, which was specifically drilled to provide representative material for the test work program and had returned an intersection of 50m at 3.99g/t gold1. The oxide sample was from a down hole depth of 5m to 27m and the transitional sample was from 27m to 50m. The fresh rock sample was obtained from ¼ HQ core from a down hole depth of 180m to 250m in hole RDSK18-029, which had returned an intersection of 51m at 2.22g/t gold2.
PREVIOUS METALLURGICAL TEST WORK RESULTS3
The Company previously undertook bottle roll cyanide leach check analysis to provide an estimate of gold recoveries that may be achievable by processing through a conventional leach circuit.
A total of 86 samples (20 oxide and 66 fresh) were collected from reverse circulation and diamond core holes drilled across the Seko trends (SK 1-3) and were submitted for 24 hr bottle roll cyanide leach analysis.
The results returned an average 95% recovery for the fresh and oxide material, with a difference of less than 5% between the original fire assay and bottle roll assays, indicating that the use of cyanide leach could be appropriate and that mineralisation at all three trends was non-refractory in nature.
- ASX Release 22 October 2019, Resource drilling & metallurgical testwork underway at Dandoko
- ASX Release 2 July 2018, Seko anomaly SK2 delivers further outstanding gold intersections
- ASX Release 6 August 2018, Excellent initial metallurgical results at Seko
PAGE 2 OF 11
7th APRIL 2020
TEST WORK RESULTS
General test work
As part of head grade assay analysis for the samples, multi-element ICP was undertaken with the results summarised as follows:
- Organic carbon content is low, indicating that the gold mineralisation does not contain mineral phases that are able to re-adsorb the gold cyanide in competition with activated carbon.
- Tellurium content is low, indicating that there should be no material issue with slow leaching telluride gold.
- Arsenic and antimony contents are low, indicating that these elements should not adversely affect leach kinetics.
- Silver content is low, which is advantageous for plant design in requiring a smaller elution circuit and less electrowinning capacity.
- Mercury content is low, which is favourable for industrial hygiene.
Physical characterisation test work
The results from the physical recovery test work highlights that the mineralisation is medium hard to hard with a bond ball work index of 10.2 - 16.0 kWh/t and is moderately abrasive to abrasive with an abrasion index of 0.05 - 0.31.
The work index and abrasiveness values are softer or comparable to tier 1 gold mining operations in the immediate region. For comparison, values realised by B2 Gold as part of the Fekola Project Definitive Feasibility Study included a ball mill work index of 14.1 - 19.7 kWh/t and an abrasion index of 0.21 - 0.884.
PRODUCT | BOND | ABRASION | ||||||||||||||||
TYPE | SIZE | BALL WI | HARDNESS | INDEX | ABRASIVENESS | |||||||||||||
P80 (µM) | (kWh/t) | (AI) | ||||||||||||||||
Oxide | 68 | 10.2 | Medium | 0.0498 | Moderately Abrasive | |||||||||||||
hardness | ||||||||||||||||||
Transitional | 83 | 15.2 | Hard | 0.3139 | Abrasive | |||||||||||||
Fresh | 77 | 16.0 | Hard | 0.1984 | Moderately Abrasive | |||||||||||||
Table 1: Seko rock parameter results
- B2 Gold Corp Fekola NI 43-101 Technical Report filed on SEDAR with effective date of 30 June 2015
PAGE 3 OF 11
7th APRIL 2020
Leach kinetics, flotation test work & grind size variability
The results from the leach recovery tests were very good, with the results indicating:
- Cyanide leaching was rapid and essentially complete within 24 hours.
- For the oxide mineralisation, a finer grind size did not improve the gold recovery and that a P80 grind size of 75 microns is sufficient to generate excellent recoveries (Table 2).
- For the transition and fresh mineralisation, reducing the grind size from 75 to 53 microns improved gold recovery (Figure 1).
- A finer grind size and resultant improved liberation resulted in the fresh mineralisation achieving a better extraction than the direct cyanidation bottle roll BLEG test work.
- Cyanide consumption is low for all mineralisation types, and whilst lime consumption for oxide mineralisation was relatively high, this is not atypical for saprolite ores which tend to be acidic and consume more lime.
- A very good transition mineralisation gold recovery of 95.3% and fresh mineralisation gold recovery of 91.3% for 15 minutes of flotation.
Further test work was conducted on leach test residue using cyanide leach for an additional 48 hours to determine the amount of remaining free gold, an aqua regia digest to determine sulphide encapsulated gold, and fire assay to determine gold in silicates.
Figure 2 highlights that for the transitional and fresh mineralisation, almost all remaining gold is encapsulated in pyrite, that there is limited further potential for gold recovery without a significantly finer grind, and that the test conditions are extracting almost all cyanide leachable gold.
GOLD | CONSUMPTION | ||||||||||||||||||||||||||||||||||||||||||
GRIND | |||||||||||||||||||||||||||||||||||||||||||
TYPE | FLOWSHEET | SIZE | LEACH | LEACH | RESIDUE | FLOTATION | FLOTATION | TAIL | BLEG | NACN | LIME | ||||||||||||||||||||||||||||||||
P80 (µm) | FEED | RECOVERY | FEED | RECOVERY | RECOVERY | ||||||||||||||||||||||||||||||||||||||
(PPM) | (PPM) | (Kg/t) | (Kg/t) | ||||||||||||||||||||||||||||||||||||||||
(PPM) | (%) | (PPM) | (%) | (%) | |||||||||||||||||||||||||||||||||||||||
Oxide | Cyanide | 75 | 4.41 | 94.1 | 0.26 | - | - | - | 96.7 | 0.15 | 3.19 | ||||||||||||||||||||||||||||||||
Leach | |||||||||||||||||||||||||||||||||||||||||||
Trans. | Cyanide | 53 | 5.99 | 84.7 | 0.92 | - | - | - | 86.3 | 0.10 | 1.07 | ||||||||||||||||||||||||||||||||
Leach | |||||||||||||||||||||||||||||||||||||||||||
Fresh | Cyanide | 53 | 2.76 | 88.0 | 0.33 | - | - | - | 84.8 | 0.15 | 1.14 | ||||||||||||||||||||||||||||||||
Leach | |||||||||||||||||||||||||||||||||||||||||||
Oxide | Flotation | Not tested | |||||||||||||||||||||||||||||||||||||||||
Trans. | Flotation | 75 | - | - | - | 6.44 | 95.3 | 0.34 | - | - | |||||||||||||||||||||||||||||||||
Fresh | Flotation | 75 | - | - | - | 2.57 | 91.3 | 0.24 | - | - | |||||||||||||||||||||||||||||||||
Table 2: Seko cyanide leach and flotation recovery results
PAGE 4 OF 11
7th APRIL 2020
100%
95%
90%
85%
80%
75%
70%
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Feed - 75 microns | Feed - 53 microns | |||
Oxide | Transitional | Fresh | ||||||
Figure 1: Total gold recovery at P80 grind size of 75µm and 53µm | ||||||||
Recovered | Remaining Free | Encapsulated in Pyrite | Encapsulated in Gangue | |||||
tested | |||||
Not | |||||
Oxide 75um | Oxide 53um | Trans 75um | Trans 53um | Fresh 75um | Fresh 53um |
Figure 2: Mode of gold occurrence at P80 grind size of 75µm and 53µm
Gravity test work
The gravity testwork indicated that the gravity recoverable gold (GRG) content was 52.6% for the oxide composite, 30.6% for the transition composite and 30.3% for the fresh composite (Table 3), highlighting the potential for GRG concentration to recover liberated free gold for the oxide mineralisation.
A decision on whether to utilise a gravity gold circuit for oxide mineralisation will be assessed as part of the Scoping Study and will be informed by the proportion of oxide material in the maiden MRE.
TYPE | HEAD GRADE | RECOVERY TO | GRIND SIZE | |||||||||
(g/t) | CONCENTRATE (%) | P80 (µm) | ||||||||||
Oxide | 4.83 | 52.6% | 75 | |||||||||
Transitional | 6.68 | 30.6% | 75 | |||||||||
Fresh | 2.71 | 30.3% | 75 | |||||||||
Table 3: Seko gravity gold results
PAGE 5 OF 11
7th APRIL 2020
FURTHER WORK
Drilling is ongoing at SK1 North in order to define the extents of mineralisation and this will be incorporated into the MRE. As part of this program, additional material from SK1 and SK3 will be collected and dispatched for metallurgical test work to characterise these zones.
It is intended that work on a Scoping Study will commence upon completion of the MRE. Further detailed metallurgical work will be undertaken when informed by the results of the upcoming MRE and Scoping Study.
- ENDS -
This announcement is authorised for release by Oklo's Managing Director, Simon Taylor.
For further information, please contact:
Simon Taylor
Managing Director
T: +61 2 8319 9233
E: staylor@okloresources.com
Competent Person's Declaration
The information in this announcement that relates to Exploration Results is based on information compiled by geologists employed by Africa Mining (a wholly owned subsidiary of Oklo Resources) and reviewed by Mr Simon Taylor, who is a member of the Australian Institute of Geoscientists. Mr Taylor is the Managing Director of Oklo Resources Limited. Mr Taylor is considered to have sufficient experience deemed relevant to the style of mineralisation and type of deposit under consideration, and to the activity that he is undertaking 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" (the 2012 JORC Code). Mr Taylor consents to the inclusion in this report of the matters based on this information in the form and context in which it appears.
The information in this announcement that relates to Metallurgical Test Work Results is based on information reviewed by Mr Geoff Duckworth (B.Eng (Chem), M. Eng Sc, PhD, FIChemE, MIEAust, FAusIMM, RPEQ 2702). Mr Duckworth is an independent consulting engineer working for Lycopodium Minerals Pty Ltd. Mr Duckworth has 40 years of relevant experience in this area of work. Mr Duckworth consents to the inclusion in this announcement of the matters based on information provided to him and in the form and context in which it appears.
This report contains information extracted from previous ASX market announcements dated 2nd July 2018, 6 August 2018 and 22nd October 2019, reported in accordance with the JORC Code (2012) and available for viewing at www.okloresources.com. Oklo Resources confirms that in respect of these announcements it is not aware of any new information or data that materially affects the information included in any original ASX market announcement.
PAGE 6 OF 11
7th APRIL 2020
Appendix 1 - Metallurgical Test Program Flow Sheet
LYCOPODIUM MINERALS PTY LTD/ OKLO RESOURCES
DANDOKO GOLD PROJECT
SAMPLE 1 | REPRESENTATIVE BLEND OXIDE MATERIAL ~ 80 kg 1/2 PQ diamond Core | |
SAMPLE 2 | REPRESENTATIVE TRANSITION MATERIAL | ~80 kg 1/2 PQ diamond core |
SAMPLE 3 | REPRESENTATIVE FRESH MATERIAL | ~80 kg 1/4 HQ diamond core |
FOR EACH SEPARATE SAMPLE - CONDUCT THE FOLLOWING:
CONTROL CRUSH TO < 63.0mm
HOMOGENISE / SPLIT
COMMINUTION TESTWORK
1 x 8.0 Kg | 1 x 10.0 Kg | |||
SELECT 4 x 400 g | CONTROL CRUSH | |||
SUB-SAMPLES | TO < 3.35 mm | |||
CONDUCT BOND | CONDUCT | |||
ABRASION INDEX | BOND BALL MILL | |||
DETERMINATION | WORK INDEX | |||
DETERMINATION | ||||
RETAIN ALL | ||||
RESERVES | RETAIN | ALL | ||
RESERVES |
GRG EXTRACTION
SAMPLE 1 REPRESENTATIVE BLEND OXIDE MATERIAL
SAMPLE 2 REPRESENTATIVE TRANSITION MATERIAL
SAMPLE 3REPRESENTATIVE FRESH MATERIAL
FOR EACH SAMPLE SEPARATELY - CONDUCT THE FOLLOWING:
CONTROL CRUSH < 3.35 mm
HOMOGENISE & SPLIT : VIA ROTARY SAMPLE DIVIDER AND PREPARE 1 x 20 kg bulk sample, 15 x 1 kg charges + RESERVE
1 x 20 kg
SAMPLE 1
SAMPLE 2
FOR EACH SAMPLE SEPARATELY
CRUSH ENTIRE SAMPLE TO
100% -2.0 mm
ROTARY SPLIT COMPOSITE
INTO 15 x 1.0 kg SUB SAMPLES + RESERVE
1 x 0.5 kg | 3 x 1 kg | 1 x 10 kg | ||||||||||
HEAD ASSAY | GRIND | GROUND TO P80 = 850 μm | ||||||||||
Au (duplicate), | ESTABLISHMENT | |||||||||||
Ag, As | TESTS MATERIAL PASSED THROUGH A | |||||||||||
STOTAL | P80 = 850 μm | 3" LAB SCALE KNELSON | ||||||||||
SSULPHIDE | P65 = 75 μm (P80 = 106 μm) | |||||||||||
P80 = 75 μm | ||||||||||||
KNELSON TAILS | KNELSON CONCENTRATE | |||||||||||
DRIED, SPLIT AND GROUND TO MERCURY | ||||||||||||
P65 = 75 μm | AMALGAMATION | |||||||||||
LEACH RESIDUE | ||||||||||||
LOADED AMALGAM | ||||||||||||
ANALYSE : | ||||||||||||
TOTAL Au | ||||||||||||
MATERIAL PASSED THROUGH A | ||||||||||||
3" LAB SCALE KNELSON | ||||||||||||
KNELSON TAILS | KNELSON CONCENTRATE | |||||||||||
DRIED, SPLIT AND GROUND TO MERCURY | ||||||||||||
P80 = 75 μm | AMALGAMATION | |||||||||||
LEACH RESIDUE | ||||||||||||
LOADED AMALGAM | ||||||||||||
ANALYSE : | ||||||||||||
TOTAL Au | ||||||||||||
MATERIAL PASSED THROUGH A | ||||||||||||
3" LAB SCALE KNELSON | ||||||||||||
KNELSON TAILS | KNELSON CONCENTRATE | |||||||||||
DRIED, WEIGHED, SPLIT | MERCURY | |||||||||||
AMALGAMATION | ||||||||||||
RESERVE | KNELSON TAILS | |||||||||||
(TO LEACH TESTWORK IN FIGURE 3 | ||||||||||||
IF SELECTED ONLY) | ANALYSE | |||||||||||
TOTAL Au (DUPL.) | LOADED AMALG RESIDUE (DRY AND WEIGH THE SAMPLE) |
ANALYSE : ANALYSE :
TOTAL Au TOTAL Au
DIRECT CYANIDATION | FLOATATION | ||||||||||||||||||||||
15 x 1 kg | |||||||||||||||||||||||
SAMPLE 1 REPRESENTATIVE BLEND OXIDE MATERIAL | SAMPLE 2 REPRESENTATIVE PRIMARY MATERIAL | ||||||||||||||||||||||
SAMPLE 2 REPRESENTATIVE PRIMARY MATERIAL | SAMPLE 3 REPRESENTATIVE | FRESH MATERIAL | |||||||||||||||||||||
SAMPLE 3 REPRESENTATIVE FRESH MATERIAL | |||||||||||||||||||||||
FOR EACH SAMPLE SEPARATELY PROVIDE FOLLOWING | |||||||||||||||||||||||
FOR EACH SAMPLE SEPARATELY PROVIDE FOLLOWING | |||||||||||||||||||||||
1 x 2.0kg | RESERVE | ||||||||||||||||||||||
1 x 0.5kg | 1 x 1kg | 1 x 1kg | 1 x 1kg | 1 x 3kg | 2 x 1kg | 1 x 1.0kg | 1 x 1.0kg | RESERVE | |||||||||||||||
(USE KNELSON TAIL IF | GRIND TO P80: 75um | ||||||||||||||||||||||
HEAD ASSAYS : | TRUE SG | BLEG | SCREEN FIRE | MINERALOGY | GRIND | GRAVITY SELECTED) | GRIND TO P80: 53um | ||||||||||||||||
Au [DUPL] | ASSAY : 75 um | ESTABLISHMENT | ROUGHER KINETIC FLOTATION TEST | ||||||||||||||||||||
Ag, As, Hg, Fe, Te, Sb, Cu | GRIND TO P80: 75 μm | TESTS | GRIND TO P80: 75 um | DIRECT CYANIDATION | WITH TIMED CONCENTRATES: | ||||||||||||||||||
C TOTAL | P80: 75 μm | TIME LEACH | |||||||||||||||||||||
CORGANIC | GRAVITY SEPARATION | P80: 53 μm | DIRECT CYANIDATION | TESTWORK : | * FLOAT 1, 4, 5, 5 MINUTES | ||||||||||||||||||
STOTAL | USING KNELSON | TIME LEACH | BOTTLE ROLL | * CuSO4 60 g/t | |||||||||||||||||||
SSULHIDE | TESTWORK : | * 40% SOLIDS (w/w) | * PAX 60 g/t STAGED | ||||||||||||||||||||
26+ element ICP Scan | SUBMIT CON & TAIL FOR | BOTTLE ROLL | * pH :10.5 [LIME] | * FROTHER AS REQUIRED | |||||||||||||||||||
DETAILED MINERALOGY | * 40% SOLIDS (w/w) | MAINTAIN pH > 10 | * NATURAL pH | ||||||||||||||||||||
(CON QEM*SCAN, TAIL XRD) | * pH :10.5 [LIME] | * NaCN : 0.05% (w/v) | * ~35% SOLIDS (w/w) | ||||||||||||||||||||
MAINTAIN pH > 10 | MAINTAIN > 0.035% | * ANALYSE PRODUCTS: | |||||||||||||||||||||
* NaCN : 0.05% (w/v) | * Pb(NO 3)2 100 g/t | Au, Fe, Stot | |||||||||||||||||||||
MAINTAIN > 0.035% | (TRANS & FRESH ONLY) | ||||||||||||||||||||||
* Pb(NO 3)2 100 g/t | OXYGEN SPARGE | ||||||||||||||||||||||
(TRANS & FRESH ONLY) | * DURATION : 48 HOURS | ||||||||||||||||||||||
OXYGEN SPARGE | * SAMPLE @ 4, 8, 24, 32 & 48 h | ||||||||||||||||||||||
* DURATION : 48 HOURS | * MONITOR pH, DO & NaCN LEVELS | ||||||||||||||||||||||
* SAMPLE @ 4, 8, 24, 32 & 48 h | * ANALYSE LEACH | ||||||||||||||||||||||
* MONITOR pH, DO & NaCN LEVELS | SOLUTIONS : Au | ||||||||||||||||||||||
* ANALYSE LEACH | * ANALYSE LEACH | ||||||||||||||||||||||
SOLUTIONS : Au | RESIDUE : Au | ||||||||||||||||||||||
* ANALYSE LEACH | |||||||||||||||||||||||
RESIDUE : Au | RETAIN ALL LEACH RESIDUES | ||||||||||||||||||||||
RETAIN ALL LEACH RESIDUES | DIAGNOSTIC LEACH TESTWORK | ||||||||||||||||||||||
3 STAGE | |||||||||||||||||||||||
DIAGNOSTIC LEACH TESTWORK | * DIRECT CYANIDATION [@0.2% NaCN w /v] | ||||||||||||||||||||||
3 STAGE | * AQUA REGIA |
- DIRECT CYANIDATION [@0.2% NaCN w /v] * FIRE ASSAY
- AQUA REGIA
- FIRE ASSAY
PAGE 7 OF 11
7th APRIL 2020
JORC CODE, 2012 EDITION - TABLE 1
Section 1 Sampling Techniques and Data
CRITERIA
JORC CODE EXPLANATION | COMMENTARY | |
Sampling techniques
- Nature and quality of sampling, measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used.
- 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.
- Previous work indicated comparable recoveries and mineralogical behaviour from each of the three Seko prospects.
- Seko 2 material was selected for study use due to it being the central prospect and having the most extensive oxide material at time of sample selection.
- Intervals were selected to represent an oxide, transitional and deep fresh rock sample to provide indicatives behaviour of the three main material classifications that might be expected.
- Half core diamond PQ core was sampled as 1m composites that were consolidated into ~80kg bulk samples and homogenised for the oxide and transitional sample.
- Quarter core diamond HQ core was sampled as 1m composites that were consolidated into ~80kg bulk samples and homogenised for the fresh sample.
Drilling techniques
Drill sample recovery
► | Drill type (e.g. core, reverse circulation, open<> | ► | All core used for the metallurgical study was |
hammer, rotary air blast, auger, Bangka, sonic, etc) | collected via a diamond triple tube PQ or HQ | ||
and details (e.g. core diameter, triple or standard | drilling method. | ||
tube, depth of diamond tails, face | |||
other type, whether core is oriented and if so, by | |||
what method, etc). | |||
► | Method of recording and assessing core and chip | ► | Triple tube DD technique was used to ensure |
sample recoveries and results assessed. | maximal recovery. | ||
► | Measures taken to maximise sample recovery and | ► | Core recoveries are recorded and monitored at the |
ensure representative nature of the samples. | drill rig site. |
- 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.
Logging
Sub-sampling techniques and sample preparation
- 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.
- Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography.
- The total length and percentage of the relevant intersections logged.
- If core, whether cut or sawn and whether quarter, half or all core taken.
- If non
- For all sample types, the nature, quality and appropriateness of the sample preparation technique.
- Quality control procedures adopted for all sub
- Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second
- Whether sample sizes are appropriate to the grain size of the material being sampled.
- All drill samples were geologically logged by Oklo Resources subsidiary Africa Mining geologists.
- Geological logging used a standardised logging system.
- Samples were prepared and sampled as per flow sheet in Appendix 1.
- Three samples of an oxide, transitional and fresh nature to explore the representativeness of the material. Further follow up test work based on these results are planned.
PAGE 8 OF 11
7th APRIL 2020
CRITERIA
Quality of assay data and laboratory tests
Verification of sampling and assaying
Location of data points
Data spacing and distribution
JORC CODE EXPLANATION
- The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.
- For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc.
- Nature of quality control procedures adopted (e.g. standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been established.
- The verification of significant intersections by either independent or alternative company personnel.
- The use of twinned holes.
- Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols.
- Discuss any adjustment to assay data.
- Accuracy and quality of surveys used to locate drill holes (collar and down
- Specification of the grid system used.
- Quality and adequacy of topographic control.
- Data spacing for reporting of Exploration Results.
- Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied.
- Whether sample compositing has been applied.
COMMENTARY
► | Samples were prepared and sampled as per flow |
sheet in Appendix 1. | |
► | Work undertaken is of a scoping nature and |
procedures, accuracy and extent of analysis are | |
appropriate for this level of study. | |
► | No external test work was undertaken. Further |
follow up test work based on these results are | |
planned. | |
► | ALS Metallurgy Pty Ltd test work was review by |
Lycopodium Minerals Limited. | |
► | Further follow up test work based on these results |
are planned. | |
► | Not applicable as sample were bulk in nature and |
designed to be representative of a broad area. | |
► | All data was collected from the Seko 2 prospect. |
► | Work undertaken is of an initial scoping nature and |
further work is required and planned to provide | |
further representative metallurgical characteristics. | |
► | No Mineral Resource Estimation or Exploration |
Target has been established, though the study | |
work is sufficient to allow for the application of | |
metallurgical related Modifying Factors to support | |
the evaluation of the economic viability of a deposit | |
if an MRE was estimated. |
Orientation of data in relation to geological structure
Sample security
Audits or reviews
- Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type.
- If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material.
- The measures taken to ensure sample security.
- The results of any audits or reviews of sampling techniques and data.
► | Work undertaken is of an initial scoping nature and |
further work is required and planned to provide | |
further representative metallurgical characteristics. | |
► | Sample material was prepared by Oklo's subsidiary |
company staff and shipped to ALS Metallurgy Pty | |
Ltd in Australia via tracked courier within locked | |
containers. | |
► | ALS Metallurgy Pty Ltd test work was reviewed and |
reported to the Company by Lycopodium Minerals | |
Limited. |
PAGE 9 OF 11
7th APRIL 2020
Section 2 Reporting of Exploration Results
CRITERIA | JORC CODE EXPLANATION |
Mineral | ► Type, reference name/number, location and |
tenement and | ownership including agreements or material issues |
land tenure | with third parties such as joint ventures, |
status | partnerships, overriding royalties, native title |
interests, historical sites, wilderness or national park | |
and environmental settings. |
► The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.
CRITERIA
► | The results reported in this report are all contained |
within the Dandoko Exploration Permit, Gombaly | |
Exploration Permit which are held 100% by Africa | |
Mining SARL, a wholly owned subsidiary of Oklo | |
Resources Limited. | |
► | The Dandoko permit (100km2) which was renewed |
on the 10/8/17, for a period of 3 years and renewable | |
twice, each for a period of 2 years: | |
► | The Gombaly permit (34km2) which was granted |
on the 10/8/17, for a period of 3 years and | |
renewable twice, each for a period of 2 years |
Exploration done by other parties
Geology
Drill hole Information
Data aggregation methods
- Acknowledgment and appraisal of exploration by other parties.
- Deposit type, geological setting and style of mineralisation.
- A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes:
- easting and northing of the drill hole collar
- elevation or RL (Reduced Level - elevation above sea level in metres) of the drill hole collar
- dip and azimuth of the hole
- down hole length and interception depth
- hole length.
- If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case.
- In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut
- Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation
► | The area that is presently covered by the Dandoko |
permit was explored intermittently by Compass | |
Gold Corporation between 2010 and 2013. | |
► | Exploration consisted of aeromagnetic surveys, |
gridding, soil sampling and minor reconnaissance | |
(RC) drilling. | |
► | The area that is presently covered by the Mousalla |
permit was explored intermittently by Compass | |
Gold Corporation between 2010 and 2013. | |
► | Exploration consisted of aeromagnetic surveys, |
gridding, soil sampling. | |
► | Ashanti Mali undertook reconnaissance soil |
sampling surveys over part of the license area. | |
► | The deposit style targeted for exploration is |
orogenic lode gold. | |
► | This style of mineralisation can occur as veins or |
disseminations in altered (often silicified) host rock | |
or as pervasive alteration over a broad zone. | |
► | Deposit are often found in close proximity to linear |
geological structures (faults & shears) often | |
associated with deep | |
► | Lateritic weathering is common within the project |
area. The depth to fresh rock is variable and may | |
extend up to 50-70m below surface and in this drill | |
program weathering of >150m was encountered. | |
► | Not applicable as exploration results are not |
reported. |
- Not applicable as exploration results are not reported.
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7th APRIL 2020
CRITERIA | JORC CODE EXPLANATION | CRITERIA | ||||
Relationship between mineralisation widths and intercept lengths
should be stated and some typical examples of such aggregations should be shown in detail.
- The assumptions used for any reporting of metal equivalent values should be clearly stated.
- These relationships are particularly important in the reporting of Exploration Results.
- If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported.
- If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g. 'down hole length, true width not known').
- Not applicable as exploration results are not reported.
Diagrams
Balanced reporting
Other substantive exploration data
Further work
- Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views.
- Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results.
- Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances.
- The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large
- Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.
- N/A
- The results of all metallurgical tests performed have been reported on. No results have been excluded.
- N/A
- Future metallurgical test work programs will be informed by the relative proportions of oxide, transitional and fresh material from the prospects and be designed to be further representative of any resources estimated by the Company.
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Oklo Resouces Limited published this content on 07 April 2020 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 06 April 2020 23:42:04 UTC