Wrap Text
Prieska Zinc-Copper Project Achieves Positive Initial Metallurgical Test Work Results
Orion Minerals NL
Incorporated in the Commonwealth of Australia
Australian Company Number 098 939 274
ASX share code: ORN
JSE share code: ORN
ISIN: AU000000ORN1
PRIESKA ZINC-COPPER PROJECT ACHIEVES POSITIVE INITIAL METALLURGICAL TEST WORK RESULTS
- Initial phase of test work confirms Prieska deposit is amenable to concentration by froth flotation to produce saleable
concentrate products.
- Test work indicates potential to match or exceed historic mine metallurgical performance.
- Deep Sulphide Target achieved rougher recoveries exceeding 89% for copper and 93% for zinc, for a differential
flotation flowsheet aimed at producing separate copper and zinc concentrates.
- +105 Level Target (Open Pit) achieved recoveries exceeding 89% for copper and 91% for zinc, in a combined bulk
cleaner concentrate.
Orion Minerals NL (ASX/JSE: ORN) (Orion or the Company) is pleased to announce that the initial phase of metallurgical
test work at the Prieska Zinc-Copper (Prieska) Project in South Africa, has yielded positive results that demonstrate the
potential for Prieska to produce high quality marketable zinc and copper concentrates (summarised in Table 1 below).
Total Recovered to
Test Head Grade Combined Tails
Concentrate
Test Description Cu
Mass Zn Rec. Mass
Cu (%) Zn(%) Rec. Cu (%) Zn(%)
(%) (%) (%)
(%)
Cu Rich Deeps Rougher 2.41 2.79 37 93.5 93.4 63 0.25 0.29
Zn-Rich Deep Rougher 1.47 6.48 34 94.1 96.9 66 0.13 0.30
Zn-Rich Supergene Rougher-Cleaner 1.53 8.87 17 92.0 92.8 83 0.19 0.94
Copper Concentrate Zinc Concentrate
Test Description Cu Zn Cu Cu Zn
Cu Rec. Zn Rec. Zn Rec.
Grade Grade Rec. Grade Grade
(%) (%) (%)
(%) (%) (%) (%) (%)
Cu Rich Deeps Rougher 89.5 12.0 22.2 3.4 4.0 0.5 71.2 10.3
Zn-Rich Deep Rougher 88.9 8.6 10.4 4.4 5.2 0.4 86.6 30.5
Zn-Rich Supergene Rougher-Cleaner - - - - 89.7 8.0 91.2 47.2
“Figures" referred to throughout this announcement can be viewed on the pdf version of the announcement, available on
the Company's website, www.orionminerals.com.au.
Table 1: Summary of Initial Metallurgical Test Work Results.
The results confirm that the remaining Prieska mineralisation, intersected to date, also responds well to metal concentration
by froth flotation and recoveries, such that matching or exceeding historical performance may be expected. All samples
tested achieved greater than 92% copper and zinc recoveries into rougher concentrates, which are the products of the first
stage of froth flotation. Mass pulls to rougher concentrates ranging between 27% and 37% demonstrated the materials’
amenability to concentration.
Optimised rougher flotation conditions to produce differentiated copper and zinc concentrates from the Deep Sulphide
Target have also been determined, as have preliminary rougher conditions to produce a bulk copper and zinc concentrate
from the shallow +105 Level Target (Open Pit). Historical rougher flotation conditions have been improved on, through a
combination of varying reagent dosages and the use of supplementary modern reagents. The resultant rougher products
are well-suited for upgrading in cleaner circuits to produce saleable products. Cleaner flotation test work is continuing.
The initial test work is being undertaken to verify the amenability to recovery and concentration using froth flotation, of both
the remaining massive sulphide mineralisation and the supergene mineralisation that is being targeted for first production
using open pit mining. Froth flotation was used successfully when the Prieska Copper Mine operated between 1971 and
1991. During that period, some 45.6 Mt of ore was processed to produce 428kt of copper and 1.01Mt of zinc as high quality
concentrates1. Mine records show that a life-of-mine metal recovery of 85% for Cu and 84% for Zn was achieved (refer to
Figure 1 for historical metallurgical performance of Prieska Mine) (2.).
Figure 1: Prieska Mine historic production and metallurgical performance 1971 -1991.
Interviews with the Prieska Copper Mine’s then-Concentrator Manager (3.), who oversaw ore processing operations from
1986, revealed that supergene ore was blended with sulphide ore during the last four years of mine life and that good metal
recoveries were achieved through careful management and reagent modification.
(1.) Obtained from mine production records.
(2.) Obtained from mine production records.
(3.) Bryan Broekman, MBA, B.Sc. Eng. (Chemical), was the Senior Consulting Metallurgist for Anglovaal.
The ongoing test work aims at confirming that:
- all variants of hypogene and supergene sulphide mineralisation, intersected in drilling to date, are amenable to
recovery and concentration using froth flotation;
- grade variation within the deposit, from high copper to high zinc grade mineralisation, does not negatively affect
the flotation response;
- the Prieska mineralisation is amenable to modern, conventional flotation reagents; and
- flotation recoveries and concentrate grades may potentially be enhanced with finer grinding.
The subsequent phase of metallurgical test work, now being commenced, further to successful conclusion of the initial
test work phase, is directed at developing optimum cleaner conditions, comminution characterisation, variability
assessments and other design test work required to formulate the most profitable processing design.
The metallurgical test work program is being undertaken as part of the mine feasibility study scheduled for completion in
Q4 of 2018 (4.). South African-based engineering firm, DRA Projects SA Pty Ltd (DRA), is the appointed lead consultant
conducting the feasibility study, supported by several industry-recognised specialists to oversee key study disciplines. Test
work is being performed by Mintek Laboratories in Johannesburg, South Africa.
Test Work Program
Detailed metallurgical test work will be conducted using diamond drill core samples obtained from mineralised intersections
in 21 holes drilled across the mineralised zones of the Prieska deposit that are targeted for mining, (refer Figure 2 for
location of metallurgical sample holes). These zones are generally demarcated into the near-surface supergene sulphide
zones (+105 Level Target (Open Pit)) and the deeper hypogene sulphide zones Deep Sulphide Target., (refer Figure 3 for
targeted mineralised zones). The +105 Level Target (Open Pit) is being considered for mining by open pit methods while
the Deep Sulphide Target is being assessed for extraction by underground mining methods utilising the significant
underground infrastructure remaining from the historic mine such as shafts and declines.
Figure 2: Plan view showing location of drill holes used to obtain samples for metallurgical test work, within
Prieska mineralisation envelope.
(4.) Refer to ASX release 11 July 2017.
Figure 3: Cross-section of the Prieska deposit’s targeted mineralisation.
The complete metallurgical test work program will consist of flotation scouting, flotation optimisation, comminution
characterisation, variability assessments and advanced design work, to determine the most profitable process design.
The results presented in this announcement form part of the flotation scouting stage of the whole program. Flotation
scouting work is being conducted on drill core composite samples obtained from 3 of the 21 drill holes (5.), with a total
mass of approximately 130kg, (refer Figures 2 and 4 for sample sources).
This test work is aimed at demonstrating the potential for bulk and differential copper-zinc rougher flotation, as well as
establishing the benefit of concentrate re-grind processes on core samples extracted from the following ore zones:
- +105 Level Target zone containing zinc-rich mineralisation;
- +105 Level Target zone containing copper-rich mineralisation (results pending);
- Deeps Sulphide Target zones containing zinc-rich mineralisation; and
- Deeps Sulphide Target zones containing copper-rich mineralisation.
Mineralised samples from the different zones are being processed through a laboratory bench-scale differential copper-
zinc rougher flotation circuit, using chemical reagents currently available in the market. Rougher rate tests for each zone
are performed using the flotation conditions that were successfully applied historically at Prieska Copper Mine. In addition
to the rougher rate tests, a series of reagent optimisation tests and a single concentrate re-grind test have been performed
to assess the benefit of concentrate re-grinding.
(5.) Hole ID’s OCOD077 and OCOD95 for the supergene samples and OCOD048-D2-6 for the Deeps samples.
Figure 4: Longitudinal projection of the Prieska deposit showing the sample sources for the initial metallurgical
test work.
Test Work Results
Based on metallurgical test results obtained to date, the following has been achieved, (Table 1 provides a summary of the
results):
- the copper-rich material from the Deep Sulphide Target responded well to a differential rougher float, achieving
89.5% copper rougher recovery to the copper concentrate and 93.4% zinc rougher recovery to the combined
copper and zinc concentrates, under optimal rougher flotation conditions;
- the zinc-rich material from the Deep Sulphide Target also responded well to a differential rougher float, achieving
88.9% copper rougher recovery to the copper concentrate and 96.9% zinc rougher recovery to the combined
copper and zinc concentrates, under optimal rougher flotation conditions;
- the zinc-rich supergene material from the +105 Level Target responded well to a bulk flotation flowsheet,
achieving 89.7% copper and 91.2% zinc recovery into a bulk concentrate after rougher flotation, regrind and
cleaning. A marketable concentrate with a grade of 47% zinc and 8% copper was produced.
Follow-up Work
The positive results allow the test work program to progress to the next phase. This follow-on work entails conclusion of the
scouting work on the copper-rich mineralised supergene zone of the +105 Level Target (Open Pit). Further, bulk flotation,
differential flotation, cleaner flotation and concentrate regrind tests will be undertaken to determine the expected cleaner
upgrade potential and ultimately expected concentrate grades for marketing assessments. Further comminution
characterisation and variability assessments will also be conducted as part of the detailed variability test work program.
Orion’s Managing Director and CEO, Errol Smart, commented on the result:
“The excellent flotation response of both the supergene and hypogene sulphides is encouraging and confirms that our
design team is on track to improving on the already successful processing route that was historically used at the mine. We
continue to develop the operational strategy and configuration to optimise returns from mining the open pit and deep
sulphides, keeping in mind the Deep Sulphide Target will constitute the bulk of our life-of-mine plan.”
Errol Smart
Managing Director and CEO
15 November 2017
ENQUIRIES
Investors JSE Sponsor
Errol Smart – Managing Director & CEO Rick Irving
Denis Waddell – Chairman Merchantec Capital
T: +61 (0) 3 8080 7170 T: +27 (0) 11 325 6363
E: info@orionminerals.com.au E: rick@merchantec.co.za
Media
Michael Vaughan Emily Fenton
Fivemark Partners, Australia Tavistock, UK
T: +61 (0) 422 602 720 T: +44 (0) 207 920 3150
E: michael.vaughan@fivemark.com.au E: orion@tavistock.co.uk
Suite 617, 530 Little Collins Street
Melbourne, VIC, 3000
Competent Persons Statement
The information in this report that relates to Orion’s Exploration Results at the Prieska Project complies with the 2012 Edition
of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code) and
has been compiled and assessed under the supervision of Mr Errol Smart, Orion Minerals Managing Director. Mr Smart
(PrSciNat) is registered with the South African Council for Natural Scientific Professionals, a Recognised Overseas
Professional Organisation (ROPO) for JORC purposes and has sufficient experience that is relevant to the style of
mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent
Person as defined in the 2012 Edition of the JORC Code. Mr Smart consents to the inclusion in this announcement of the
matters based on his information in the form and context in which it appears. The Exploration Results are based on standard
industry practises for drilling, logging, sampling, assay methods including quality assurance and quality control measures
as detailed in Appendix 2.
Disclaimer
This release may include forward-looking statements. Such forward-looking statements may include, among other things,
statements regarding targets, estimates and assumptions in respect of metal production and prices, operating costs and
results, capital expenditures, mineral reserves and mineral resources and anticipated grades and recovery rates, and are
or may be based on assumptions and estimates related to future technical, economic, market, political, social and other
conditions. These forward-looking statements are based on management’s expectations and beliefs concerning future
events. Forward-looking statements inherently involve subjective judgement and analysis and are necessarily subject to
risks, uncertainties and other factors, many of which are outside the control of Orion. Actual results and developments may
vary materially from those expressed in this release. Given these uncertainties, readers are cautioned not to place undue
reliance on such forward-looking statements. Orion makes no undertaking to subsequently update or revise the forward-
looking statements made in this release to reflect events or circumstances after the date of this release. All information in
respect of Exploration Results and other technical information should be read in conjunction with Competent Person
Statements in this release. To the maximum extent permitted by law, Orion and any of its related bodies corporate and
affiliates and their officers, employees, agents, associates and advisers:
- disclaim any obligations or undertaking to release any updates or revisions to the information to reflect any change
in expectations or assumptions;
- do not make any representation or warranty, express or implied, as to the accuracy, reliability or completeness of
the information in this release, or likelihood of fulfilment of any forward-looking statement or any event or results
expressed or implied in any forward-looking statement; and
- disclaim all responsibility and liability for these forward-looking statements (including, without limitation, liability for
negligence).
Appendix 1: The following table lists the drill holes used for collecting metallurgical test work samples.
Site ID Target Type Hole Depth (m) Core Size Dip Azimuth UTM34S East UTM34S North RL Sample Kg's
OCOD039 Supergene Sulphides +105 MET 84.27 PQ -90.00 0.00 624 352.21 6 686 623.29 1070.27 200
OCOD046-D1 Deep Sulphides Deeps MET 1 068.05 NQ -80.00 45.00 624610.5228 6686251.974 1067.74 52
OCOD046-D2-1 Deep Sulphides Deeps MET 1 053.05 NQ -80.00 45.00 624610.5228 6686251.974 1067.74 26
OCOD048-D2-6 Deep Sulphides Deeps MET 1 103.92 NQ -80.00 45.00 624452.2686 6686374.789 1067.74 65
OCOD048-D2-7 Deep Sulphides Deeps MET 1 100.00 NQ -80.00 45.00 624452.2686 6686374.789 1067.74 100
OCOD065-D1-4 Deep Sulphides Deeps MET 1 052.72 NQ -77.00 42.00 624529.4002 6686346.275 1068.03 80
OCOD065-D1-5 Deep Sulphides Deeps MET 1 052.72 NQ -77.00 42.00 624529.4002 6686346.275 1068.03 33
OCOD066-D2 Deep Sulphides Deeps MET 1 102.14 NQ -90.00 0.00 624350.0284 6686466.11 1068.30 200
OCOD066-D3 Deep Sulphides Deeps MET 1 135.00 NQ -90.00 0.00 624350.0284 6686466.11 1068.30 88
OCOD068-D1 Deep Sulphides Deeps MET 1 029.12 NQ -90.00 0.00 624691.2249 6686077.099 1069.71 59
OCOD072-D1 Deep Sulphides Deeps MET 1 126.23 NQ -90.00 0.00 625711.5987 6685214.405 1077.44 to dispatch
OCOD074-D1 Deep Sulphides Deeps MET 1140* NQ -90.00 0.00 625815.084 6685218.764 1078.51 to dispatch
OCOD077 Supergene Sulphides +105 MET 90.93 NQ -90.00 0.00 624391.8018 6686581.717 1070.00 to dispatch
OCOD095 Supergene Sulphides +105 MET 111.90 NQ -60.00 110.00 624390.2269 6686548.743 1069.00 186
OCOD106 Oxide +105 MET 33.47 HQ -90.00 0.00 624366.4623 6686562.161 1067.00 to dispatch
OCOD106A Oxide +105 MET 45.47 HQ -90.00 0.00 624366.4623 6686562.161 1067.00 to dispatch
OCOD108 Oxide +105 MET 35.32 HQ -30.00 225.00 624366.4623 6686562.161 1067.00 to dispatch
OCOU100 Supergene Sulphides +105 MET 73.12 BX 30.00 30.00 624840.2933 6686234.947 972.00 to dispatch
OCOU102 Supergene Sulphides +105 MET 60.2 BX 30.00 45.00 624662.8427 6686351.534 975.00 to dispatch
OCOU104 Supergene Sulphides +105 MET 67.93 BX 30.00 360.00 624595.6721 6686390.886 975.00 to dispatch
OCOU109 Supergene Sulphides +105 MET 70* BX 30.00 45.00 624595.6721 6686390.886 975.00 to dispatch
* Planned depth - drilling in progress
Appendix 2: The following tables are provided to ensure compliance with the JORC Code (2012) requirements for the reporting of Exploration Results for the Prieska
Project.
Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections.)
Criteria JORC Code explanation Commentary
Sampling - Nature and quality of sampling (e.g. cut channels, random chips, or - Metallurgical samples taken from diamond half and full cores.
techniques specific specialised industry standard measurement tools appropriate - Diamond cores sampled on geological boundaries based on visual
to the minerals under investigation, such as down hole gamma mineralisation.
sondes, or handheld XRF instruments, etc.). These examples should - Samples are submitted for analysis in their entirety.
not be taken as limiting the broad meaning of sampling.
- Include reference to 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.
Drilling techniques - Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air - Diamond core drilling using NQ and BQ sized core.
blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, - Pre-collar drilled using percussion drilling on certain holes (above
triple or standard tube, depth of diamond tails, face-sampling bit or mineralisation).
other type, whether core is oriented and if so, by what method, etc.).
Drill sample - Method of recording and assessing core and chip sample recoveries - All mineralised intersections are done with core drilling.
recovery and results assessed. - Core stick-ups reflecting the depth of the drill hole are recorded at the
- Measures taken to maximise sample recovery and ensure rig at the end of each core run.
representative nature of the samples. - A block with the depth of the hole written on it is placed in the core box
- Whether a relationship exists between sample recovery and grade at the end of each run.
and whether sample bias may have occurred due to preferential - At the core yard, the length of core in the core box is measured for
loss/gain of fine/coarse material. each run. The measured length of core is subtracted from the length of
the run as recorded from the stick-up measured at the rig to determine
the core lost.
- No grade variation with recovery noted.
Logging - Whether core and chip samples have been geologically and - All percussion holes are logged on 1m intervals using visual inspection
geotechnically logged to a level of detail to support appropriate of washed drill chips and both full. Core is logged by geology and
Mineral Resource estimation, mining studies and metallurgical recorded between geological contacts by qualified geologists.
studies. - Qualitative logging of colour, grainsize, weathering, structural fabric,
- Whether logging is qualitative or quantitative in nature. Core (or lithology, alteration type and sulphide mineralogy carried out.
costean, channel, etc.) photography. - Quantitative estimate of sulphide mineralogy and quartz veining.
- The total length and percentage of the relevant intersections logged. - Logs are recorded at the core yard and entered into digital templates at
the project office.
Sub-sampling - If core, whether cut or sawn and whether quarter, half or all core - BQ and NQ core sampled in their entirety.
techniques and taken. - Sample preparation is undertaken at Mintek Johannesburg, an ISO
sample preparation - If non-core, whether riffled, tube sampled, rotary split, etc. and accredited laboratory. Mintek utilises industry best practise for sample
whether sampled wet or dry. preparation for analysis from initial sampling and sub sampling at each
- For all sample types, the nature, quality and appropriateness of the stage of the test work process.
sample preparation technique.
- Quality control procedures adopted for all sub-sampling stages to
maximise representivity of samples.
- 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.
- Whether sample sizes are appropriate to the grain size of the material
being sampled.
Quality of assay data - The nature, quality and appropriateness of the assaying and - Samples from drilling were submitted to Mintek in Johannesburg for
and laboratory tests laboratory procedures used and whether the technique is considered metallurgical test work. Samples taken during the test work process are
partial or total. dissolved in a strong alkali digest and analysing via ICP, a technique
- For geophysical tools, spectrometers, handheld XRF instruments, tailored for high grade Zn concentrates. Preliminary assaying using a
etc., the parameters used in determining the analysis including hand-held XRF machine is also done.
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.
Verification of - The verification of significant intersections by either independent or - Orion’s executive geologist is personally supervising the drilling and
sampling and alternative company personnel. sampling along with a team of experienced geologists.
assaying - The use of twinned holes. - Senior management have reviewed the raw laboratory data and
- Documentation of primary data, data entry procedures, data confirmed the calculation of the significant intersections.
verification, data storage (physical and electronic) protocols.
- Discuss any adjustment to assay data.
Location of data - Accuracy and quality of surveys used to locate drill holes (collar and - Collar data has been laid out using a handheld GPS and these
points down-hole surveys), trenches, mine workings and other locations coordinates are reported here.
used in Mineral Resource estimation. - All of the Orion drill hole collars are surveyed by a qualified surveyor
- Specification of the grid system used. using a differential GPS which may result in minor adjustments to
- Quality and adequacy of topographic control. coordinate data.
- Downhole surveys are completed using a North-Seeking Gyro
instrument.
- The historic mine survey data is in the old national Clarke 1880
coordinate system. All data is collected the surveyor is in Clarke 1880
and in UTM WGS84 Zone 34 (Southern Hemisphere). UTM WGS84
Zone 34 coordinates are reported above.
Data spacing and - Data spacing for reporting of Exploration Results. - At the Deep Sulphide Target drill holes aim to intersect mineralisation
distribution - Whether the data spacing and distribution is sufficient to establish the on approximately 100m x 100m spacing with infill drilling to be carried
degree of geological and grade continuity appropriate for the Mineral out in areas of interest as determined by results.
Resource and Ore Reserve estimation procedure(s) and - At the +105 Level Target drill holes aim to intersect mineralisation on
classifications applied. approximately 45m x 45m spacing with infill drilling to be carried out in
Whether sample compositing has been applied. areas of interest as determined by results.
- Variography studies were carried out on the historic data set for both
Targets to determine the drill spacing for Mineral Resource estimates.
Orientation of data - Whether the orientation of sampling achieves unbiased sampling of - Drilling is oriented perpendicular, or at a maximum achievable angle to,
in relation to possible structures and the extent to which this is known, considering the attitude of the mineralisation.
geological structure the deposit type. - As a result, most holes intersect the mineralisation at an acceptable
- If the relationship between the drilling orientation and the orientation angle.
of key mineralised structures is considered to have introduced a - Where surface access or geotechnical conditions do not allow access
sampling bias, this should be assessed and reported if material. to optimal drill collar positions, holes may be inclined.
- The intersections will be corrected once the mineralised zone is
modelled in three dimensions and local attitude can be accurately
determined.
- No sampling bias is anticipated as a result of hole orientations.
- EM surveys are completed in an orientation perpendicular to the
interpreted or intersected mineralisation.
Sample security - The measures taken to ensure sample security. - Chain of custody is managed by the Company. Samples were stored
on site in a secure locked building and then freighted directly to the lab.
Audits or reviews - The results of any audits or reviews of sampling techniques and data. - No audits or reviews have been carried out at this stage.
Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this section.)
Mineral tenement - Type, reference name/number, location and ownership including - The Prospecting Right is held by a subsidiary company of Agama
and land tenure agreements or material issues with third parties such as joint Exploration and Mining (Pty) Ltd (Agama), which is a wholly owned
status ventures, partnerships, overriding royalties, native title interests, subsidiary of Orion. As such, Orion effectively holds a 73.33% interest
historical sites, wilderness or national park and environmental in the project.
settings. - The Prospecting Right covers a strike of 2200m for the Deep Sulphide
- The security of the tenure held at the time of reporting along with any mineralisation out of a total interpreted strike of 2800m.
known impediments to obtaining a licence to operate in the area. - The Prospecting Right covers the complete known strike of the +105
Level Target.
- All of the required shaft infrastructure and lateral access underground
development is available within the Prospecting Right.
Exploration done by - Acknowledgment and appraisal of exploration by other parties. Deep Sulphide Target
other parties - All exploration and life of mine drilling (V, D and F holes) was done by
Anglovaal, resulting in a substantial amount of hard copy data from
which the Company has been able to assess the prospectivity of the
remaining mineralisation.
- The Anglovaal exploration resulted in the delineation and development
of a large mine.
+105 Level Target
- The 2012 drilling of the NW section of the +105 Level Target was
carried out by the previous owners of the Subsidiary (Orion acquired
the subsidiary in March 2017).
Geology - Deposit type, geological setting and style of mineralisation. - The Copperton deposit is a Volcanogenic Massive Sulphide deposit.
The deposit is contained in the Areachap Group, which also hosts the
Boks Puts, Areachap, Kielder, Annex Vogelstruisbult and Kantienpan
deposits.
- The historically mined section of the deposit is confined to a tabular,
stratabound horizon in the northern limb of a refolded recumbent
synform which plunges at approximately 45° to the southeast. It is
hosted within deformed gneisses of the Copperton Formation, which
have been dated at 1285 Ma and forms part of the Namaqualand
Metamorphic Complex.
- The mineralised zone outcrop has a strike of 2400m, was oxidised and
/ or affected by leached and supergene enrichment to a depth of
approximately 100m, and outcrops as a well-developed gossan. It has
a dip of between 55° and 80° to the northeast at surface and a strike of
130° to the north. The width of the mineralised zone exceeds 35m in
places but averages between 7m and 9m. The mineralised zone
persists to a depth of 1100m (as deep as 1200m in one section) after
which it is upturned.
- The +105 Level Target area comprises the oxide / supergene / mixed
zone (and a zone of remnant primary sulphides) situated from above
the upper limit of mining at approximately 100m depth up to surface.
Drill hole - A summary of all information material to the understanding of the - All location data and other drill hole information is tabulated in
Information exploration results including a tabulation of the following information Appendix 1.
for all Material drill holes:
o easting and northing of the drill hole collar
o elevation or RL (Reduced Level – elevation above sea level in
metres) of the drill hole collar
o dip and azimuth of the hole
o down hole length and interception depth
o 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.
Data aggregation - In reporting Exploration Results, weighting averaging techniques, - Not relevant as results presented are from metallurgical test work.
methods maximum and/or minimum grade truncations (e.g. cutting of high
grades) and cut-off grades are usually Material and should be stated.
- Where aggregate intercepts incorporate short lengths of high grade
results and longer lengths of low grade results, the procedure used
for such aggregation 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.
Relationship - These relationships are particularly important in the reporting of - All intersection widths quoted are down hole widths.
between Exploration Results. - Most holes intersected the mineralisation perpendicular or at high angle
mineralisation - If the geometry of the mineralisation with respect to the drill hole to the attitude of the mineralisation.
widths and intercept angle is known, its nature should be reported. - The mineralisation has complex geometry and mineralisation widths
lengths - If it is not known and only the down hole lengths are reported, there need to be estimated based on interpretation of surrounding intercepts.
should be a clear statement to this effect (e.g. ‘down hole length, true
width not known’).
Diagrams - Appropriate maps and sections (with scales) and tabulations of - Appropriate diagrams (plan, cross section and long section) are shown
intercepts should be included for any significant discovery being in the announcement text.
reported. These should include, but not be limited to a plan view of
drill hole collar locations and appropriate sectional views.
Balanced reporting - Where comprehensive reporting of all Exploration Results is not - All drill hole results referred to in the announcement, are listed in
practicable, representative reporting of both low and high grades Appendix 1. All other drill holes, including those with no mineralisation,
and/or widths should be practiced to avoid misleading reporting of have been detailed in previous announcements as detailed in the text.
Exploration Results.
Other substantive - Other exploration data, if meaningful and material, should be reported - Hardcopy maps are available for a range of other exploration data. This
exploration data including (but not limited to): geological observations; geophysical includes mine survey plans, geological maps, airborne magnetics,
survey results; geochemical survey results; bulk samples – size and ground magnetics, electromagnetics, gravity and induced polarisation.
method of treatment; metallurgical test results; bulk density, All available exploration data has been viewed by the Competent
groundwater, geotechnical and rock characteristics; potential Person.
deleterious or contaminating substances. - The mine operated from 1972 to 1991 and is reported to have milled a
total of 45.68 Mt of ore at a grade of 1.11% copper and 2.62% zinc,
recovering 0.43 Mt of copper and 1.01 Mt of zinc. Detailed production
and metallurgical results are available for the life of the mine.
- In addition, 1.76 Mt of pyrite concentrates and 8,403 t of lead
concentrates as well as amounts of silver and gold were recovered.
- Copper and zinc recoveries averaged 84.9% and 84.3% respectively
during the life of the mine.
Further work and - The nature and scale of planned further work (e.g. tests for lateral - Drilling is ongoing to test the Deep Sulphide Target.
metallurgical test extensions or depth extensions or large-scale step-out drilling). - Downhole and surface EM surveys are also in progress aimed at
work - Diagrams clearly highlighting the areas of possible extensions, delineating targets away from the historically drilled areas.
including the main geological interpretations and future drilling areas, - Scouting metallurgical test work was undertaken using samples
provided this information is not commercially sensitive. obtained from a range of lithological and spatial domains. Some 137kg
- Other exploration data, if meaningful and material, should be reported of samples was obtained from 3 holes. Full representivity from
including (but not limited to) metallurgical test results. samples will be achieved as part of the subsequent stages of
- The basis for assumptions or predictions regarding metallurgical metallurgical testwork. Variability of metallurgical characteristics
amenability. It is always necessary as part of the process of across the targeted exploration area will be tested using a set of 21 drill
determining reasonable prospects for eventual economic extraction to holes. The placement of drill holes took into consideration the need to
consider potential metallurgical methods, but the assumptions assess spacial, lithological, grade and degree of oxidation domains
regarding metallurgical treatment processes and parameters made within the targeted mineralised zones.
when reporting Mineral Resources may not always be rigorous. - The primary purpose of the metallurgical test work campaign is to verify
Where this is the case, this should be reported with an explanation of that historically-applied ore processing techniques are still applicable to
the basis of the metallurgical assumptions made. unmined extensions of the deposit.
- The metallurgical process proposed and the appropriateness of that - Historical mine production records reported the amount of material
process to the style of mineralisation. milled and the resultant concentrates produced.
- Whether the metallurgical process is well-tested technology or novel - Historical ore processing techniques are well documented.
in nature. - Interviews with personnel who supervised ore processing operations
- The nature, amount and representativeness of metallurgical test work have been conducted.
undertaken, the nature of the metallurgical domaining applied and the - The proposed metallurgical processes (froth flotation using standard
corresponding metallurgical recovery factors applied. reagent suites) are widely applied in the industry and were applied
- Any assumptions or allowances made for deleterious elements. successfully when the Prieska Copper Mine operated previously.
- The existence of any bulk sample or pilot scale test work and the
degree to which such samples are considered representative of the
orebody as a whole.
- For minerals that are defined by a specification, has the ore reserve
estimation been based on the appropriate mineralogy to meet the
specifications
Date: 15/11/2017 09:25:00 Produced by the JSE SENS Department. The SENS service is an information dissemination service administered by the JSE Limited ('JSE').
The JSE does not, whether expressly, tacitly or implicitly, represent, warrant or in any way guarantee the truth, accuracy or completeness of
the information published on SENS. The JSE, their officers, employees and agents accept no liability for (or in respect of) any direct,
indirect, incidental or consequential loss or damage of any kind or nature, howsoever arising, from the use of SENS or the use of, or reliance on,
information disseminated through SENS.