Wrap Text
Metallurgical Testwork Confirms Targeted Recoveries at the Prieska Zinc-Copper Project
Orion Minerals Limited
Incorporated in the Commonwealth of Australia
Australian Company Number 098 939 274
ASX share code: ORN
JSE share code: ORN
ISIN: AU000000ORN1
(“Orion” or “the Company”)
METALLURGICAL TESTWORK CONFIRMS TARGETED RECOVERIES WITH PRODUCTION OF
SALEABLE ZINC AND COPPER CONCENTRATES AT THE PRIESKA ZINC-COPPER PROJECT
- Completed testwork confirms metallurgical continuity across the Deep Sulphide Zone at Prieska.
- No material metallurgical zonation issues encountered.
- Excellent copper and zinc metal recoveries confirmed, in line with historical mine performance.
- Ability to produce high-quality, differentiated copper and zinc metal concentrates.
- Results will allow process plant design to proceed, as part of the Prieska BFS due in Q2 2019.
- Preliminary testwork shows potential to use safer and more environmentally-friendly froth-
flotation chemical reagents, with added benefit of delivering cost reductions.
“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.
Orion’s Managing Director and CEO, Errol Smart, commented:
“We are very pleased to have shown conclusively that the extensions of the Prieska Deep Sulphide Zone
targeted by our recently completed resource drilling are metallurgically identical to the ore that was treated
with great success for over 20 years. This is an important result, which shows that we can expect to at least
match and potentially exceed the historical plant performance and concentrate qualities.
The results from the locked-cycle testwork program confirms that we can include and use the historical mine
metallurgical performance in the ongoing Bankable Feasibility Study, allowing us to complete the design of
the process plant. We can now also provide potential concentrate off-take parties with target concentrate
specifications including minor element analyses, confirming our ability to deliver high quality concentrates.
The fact that we can produce concentrates with negligible levels of key contaminants such as manganese
or lead in our zinc concentrates is a real plus for Orion as a new base metals producer.
The additional testwork findings also indicate that we can use modern reagents and exclude cyanide from
the process, bringing both health and safety and environmental management benefits to the project while
achieving likely capital and operating cost reductions.”
Orion Minerals Ltd (ASX/JSE: ORN) (Orion) is pleased to advise that it has successfully completed follow-
up locked-cycle metallurgical testwork on the deeper mineralised domains (Deep Sulphide Zone) at its
Prieska Zinc-Copper Project (Prieska Project), located in the Northern Cape Province of South Africa.
The Prieska Deep Sulphide Zone is currently the subject of a Bankable Feasibility Study (BFS) targeted for
completion in Q2 2019. Initial results from the metallurgical testwork program were reported in June (refer
ASX release 12 June 2018) and the program has now been completed. Results have confirmed the
metallurgical continuity of the Deep Sulphide Zone with the up-dip area of the mineralised zone, where, in
the period between 1971-1991, 45 million tonnes of ore were mined and successfully processed to produce
clean and widely-marketed concentrates.
Excellent recoveries of both copper and zinc into separate, high-quality concentrates have been achieved
using the froth-flotation process that was used in historical operations. In addition, the use of modern
metallurgical reagents – which have advantages in terms of health and safety, environmental management
as well as in potential capital and operating cost savings – is showing encouraging results.
Deep Sulphide Zone (Hypogene) Test Results
The latest bench-scale, lock-cycle metallurgical tests have achieved targeted total metal recoveries, ranging
from 80% to 94% for zinc and 80% to 86% for copper into separated concentrates.
The resultant concentrates had metal grades ranging between 45% and 54% for zinc and between 20% and
26% for copper in the respective products (refer Tables 1 and 2). Gold and silver are collected in the copper
concentrates at levels that would qualify them as valuable by-products. Results are consistent with
expectations for bench-scale test work, which has limited stabilisation time and hence still opportunity for
improvement in continuous operation.
Detailed elemental analyses of the concentrates confirmed that several key deleterious elements are at
negligible levels with, notably amongst others, arsenic, bismuth, cadmium, cobalt, tellurium, thorium and
uranium at levels well below thresholds that may attract material penalty charges from most smelters or
exclude some markets. Samples were obtained from across the extent of the deposit and composited into
several blends such that a wide range of feed compositions could be assessed (refer to Table 3, Figures 5
and 6). Production scheduling using this information will further optimise resultant markable products.
Test results to date have generally equalled or exceeded the metal recoveries and concentrate grades
achieved during historical mining operations. When graphically superimposed over the historical plant
performance dataset (refer to Figures 1 and 2 below), the latest locked-cycle test results (highlighted in red)
compare favourably with the historical operational performance. The zinc and copper recovery results
correlate well to the average historical trend line.
Mine records show that over the 20-year mine life, 1.01 million tonnes of zinc and 430,000 tonnes of copper
were sold as separated, high-grade metal concentrates, with average metal recoveries of over 85% achieved
for both metals, (refer ASX release 15 November 2017).
The latest metallurgical testing program validates this substantial historical dataset which now can be
applied, along with more recent testwork results, to formulate base assumptions for ongoing mine feasibility
studies and for concentrate marketing terms.
Processing Plant Design and Cyanide Substitution
Metallurgical testing of the Prieska deposit is being conducted as part of an ongoing BFS. Outcomes from
the work program now enable the next phase of the BFS to progress, which includes the final design of the
metallurgical plant, derivation of metallurgical performance projections and optimisation of the reagent suite
to improve operating efficiency and cost control. The mineral processing plant currently being designed
employs a similar flowsheet to that used in historical mining operations, albeit with the application of modern
technology while re-utilising as much of the remaining surface infrastructure as is serviceable.
Investigations into optimising the reagent suite for the mineral processing plant are in progress with the
objective of, amongst others, substituting the use of sodium cyanide as a zinc depressant, with sodium
metabisulfite (SMBS).
The removal of sodium cyanide from the reagent suite would have significant economic and safety benefits
for the project, reducing the cost of production, avoiding any potential exposure to sodium cyanide and
eliminating the need for a detoxification section of the plant ahead of tailings storage.
Preliminary tests indicate that SMBS can effectively provide similar performances to sodium cyanide. A Deep
Sulphide Zone sample blend was tested using the standard froth-flotation flowsheet to produce copper and
zinc concentrates. The control test employed sodium cyanide, while several subsequent comparison tests
used SMBS instead of the sodium cyanide.
Test conditions for the comparison tests were adjusted for each iteration and indications were that the SMBS
reagent suite performed as well as the cyanide control test (refer to Figures 10 and 11). Further testwork is
in progress to validate these early observations. The substitution of sodium cyanide with SMBS will be a
significant improvement on the historically-applied mineral processing techniques and is in line with modern
standard practice worldwide.
Project Background
The Prieska Project is located in the Northern Cape Province of South Africa, approximately 290km south-
west of the city of Kimberley, (Figure 3). The project area encompasses the historical Prieska Copper Mine
(PCM). The PCM was profitably operated by Anglovaal as an underground zinc and copper mine, exploiting
the Copperton deposit between 1971 and 1991, processing on average three million tonnes per year to
produce 1.01 million tonnes of zinc and 430,000 tonnes of copper in concentrates (refer ASX release 15
November 2017). Run-of-mine ore was treated by froth flotation to produce separate concentrates of copper
and zinc.
Orion is now investigating the establishment of new mining operations targeting the extraction of the
remaining zinc-copper mineralisation at the Prieska volcanogenic massive sulphide (VMS) deposit.
Orion has delineated a global Mineral Resource, classified by a Competent Person and reported in
accordance with the JORC Code (2012), amounting to 29.4 million tonnes grading 3.8% zinc and 1.2%
copper, comprising, amongst others, a hypogene Inferred Mineral Resource of 27.8 million tonnes grading
3.9% zinc and 1.2% copper (Deep Sulphide Zone) (Figure 4) and a supergene Indicated Mineral Resource
amounting to 1.2 million tonnes grading 2.6% zinc and 2.4% copper (Supergene zone) (refer ASX release
9 April 2018). Mineral Resource definition work is ongoing, with the objective of improving the classification
of the Mineral Resource estimate as part of the BFS.
Mine development studies are scheduled for completion in the first half of 2019. DRA Projects South Africa
Pty Ltd (DRA) is the lead consultant appointed to consolidate the BFS, part of which includes the design of
the mineral processing plant. Metallurgical testwork is being conducted at the Mintek laboratories in
Johannesburg, South Africa. ABS Africa Pty Ltd are supervising the environmental permitting.
Errol Smart
Managing Director and CEO
22 October 2018
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 Barnaby Hayward
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 Person’s Statement
The information as presented in this report that relates to the results of metallurgical test work at the Prieska
Project is not in contravention of 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’s 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.
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 (where applicable). 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 – Deep Sulphide Zone Metallurgical Testwork
Sample Collection and Preparation
Approximately 800kg of mineralised hypogene samples were collected from diamond drilling cores.
Samples were collected from 7 holes drilled to obtain samples from across the full extent of the target
mineralised zones (refer to Table 4 and Figures 4, 5 and 6). Additional samples from three more holes
drilled in the south-western extent of the Deep Sulphide Zone are pending assessment as part of
confirmatory variability testwork (refer to Figure 6).
Samples were then composited to make up blends to assess the effect of different zinc to copper ratios,
as well as mixes of samples from different geographic locations within the Deep Sulphide Zone. Five
different blends were prepared for this testwork program, (refer to Table 3).
Deep Sulphide Zone Flowsheet
The recovery plant design flowsheet tested is based on a conventional crushing, milling and flotation
process as was effectively used previously by the Prieska Copper Mine.
The copper laboratory flow-sheet includes bench-scale operation of the following main processes:
• Crushing and milling;
• Copper rougher flotation;
• Concentrate regrind;
• Copper cleaner flotation.
Refer to Figure 7 for the flowsheet schematic.
The zinc laboratory flowsheet includes bench-scale operation of the following main processes, with the
feed being the copper rougher tails:
• Zinc rougher flotation;
• Concentrate regrind;
• Zinc cleaner flotation.
Refer to Figure 8 for the flowsheet schematic.
Test Work Methodology
Laboratory-scale, open-circuit flotation tests were conducted in 1kg batches. Each sample was milled
using a laboratory rod mill at 50% solids by mass to achieve a target grind of 70% passing 75 microns
for the hypogene samples.
The milled slurry was then transferred into a 2.5 litre flotation cell, which was agitated using a Denver
D12 flotation machine at an impellor speed of 1200 rpm. Depending on the feed mass, cleaner flotation
testing was conducted in either a 1 litre or 2 litre flotation cell which was agitated using a Denver D12
flotation machine at an impellor speed of 1000 -1200 rpm. Concentrates were collected by scraping off
the froth at 15 second intervals. All test products were then pulverised and assayed for arrange of
elements including copper, lead, zinc, iron and sulphur using the ICP analysis method.
Locked-cycle testing involves repetitive batch flotation testing, whereby the open-circuit flotation test
described is repeated five times using the re-cycled intermediate flotation streams. A product sample is
collected at the end of each cycle for ICP analysis.
Appendix 2 – Tables and Figures
Deep Sulphide Zone Copper Concentrate
Units
of Historical Blend Averag
Element Blend 1 Blend 2 Blend 3 Blend 6 Min Max
Measu Pilot Plant 4 e
re
Cu % 26.30 25.50 25.70 22.10 22.00 19.80 19.80 25.70 23.02
Zn % 4.68 3.51 8.80 9.67 9.90 12.50 3.51 12.50 8.88
Fe % 28.00 26.20 25.00 26.70 23.70 21.20 21.20 26.70 24.56
Total S % 30.70 28.90 30.20 30.30 31.80 30.80 28.90 31.80 30.40
Ag g/t 57.00 150.77 147.00 144.00 176.00 153.00 144.00 176.00 154.15
Au g/t 2.80 3.33 2.56 2.01 2.40 2.80 2.01 3.33 2.62
Table 1: Element analyses conducted on the differentiated copper concentrates produced from composite samples derived from the Deep Sulphide Zone,
(refer to Table 4 for blend grades)
Deep Sulphide Zone Zinc Concentrate
Unit of Historical
Element Blend 1 Blend 2 Blend 3 Blend 4 Min Max Average
Measure Pilot Plant
Zn % 50.37 53.87 49.60 46.50 50.90 46.50 53.87 50.22
Cu % 1.16 0.78 1.11 0.62 0.55 0.55 1.11 0.77
Fe % 10.56 6.25 10.10 17.90 1 6.07 6.07 17.90 10.08
Total S % 31.72 29.53 30.10 29.30 31.50 29.30 31.50 30.11
Ag g/t 19.40 17.27 17.50 13.90 10.80 10.80 17.50 14.87
Au g/t 1.40 0.52 0.35 0.33 0.29 0.29 0.52 0.37
Table 2: Element analyses conducted on differentiated zinc concentrates produced from composite samples derived from the Deep Sulphide Zone, (refer to Table 4 for blend grades).
Parameter Units of Blend 1 Blend 2 Blend 3 Blend 4 Blend 62 Deep Sulphide
Measure Mineral
Resources
Grades3
Composite Description 100%
%Weight 50% NW 80% NW 20% NW 80% NW 81% NW 19%
NW=North West zone SW= NW
%Weight 50% SE 20% SE 80% SE 20% SE SE
South West zone 0% SE
Sample Grade - Cu % 0.92 1.11 1.21 0.82 0.79 1.20
Sample Grade - Zn % 4.47 3.89 3.64 4.81 3.14 3.90
Sample Grade - Fe % 15.5 19.3 22.9 14.4 15.0 15.8
Grade Ratio (Zn/Cu) Zn : Cu 4.86 3.49 3.00 5.90 3.99 3.25
Table 3: Summary of blended variability composites from collected metallurgical samples and the reported Mineral Resources grades for the Deep Sulphide Zone.
Hole ID Intersection ID Tenement Target Core Size
OCOD046 OCOD046-D1 Repli NW Deeps BQ
OCOD046-D2-1 Repli NW Deeps BQ
OCOD048 OCOD048-D2-6 Repli NW Deeps NQ
OCOD048-D2-7 Repli NW Deeps NQ
OCOD065 OCOD065-D1-4 Repli NW Deeps NQ
OCOD065-D1-5 Repli NW Deeps NQ
OCOD066 OCOD066-D2 Repli NW Deeps NQ
OCOD066-D3 Repli NW Deeps NQ
OCOD068 OCOD068-D1 Repli NW Deeps NQ
OCOD074 OCOD074-D1 Repli SW Deeps NQ
OCOD072 OCOD072-D1 Vardocube SW Deeps NQ
OCOD122 OCOD122-D2 Vardocube SW Deeps NQ
OCOD122-D3 Vardocube SW Deeps NQ
OCOD134 OCOD134-D1 Vardocube SW Deeps NQ
OCOD135 OCOD135-D1 Vardocube SW Deeps NQ
Appendix 3: The following tables are provided in accordance with the JORC Code (2012) for the reporting of Exploration Results for 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 - Drilling and sampling has been undertaken during three distinct periods
techniques specific specialised industry standard measurement tools appropriate since the discovery of mineralisation. These are pre-mine exploration
to the minerals under investigation, such as down hole gamma (1968-1971) and during mine operations (1972-1984) holes ("V", "D",
sondes, or handheld XRF instruments, etc.). These examples should and "F" prefixed holes) by Anglovaal Ltd (also known as the Anglovaal
not be taken as limiting the broad meaning of sampling. Group, “Anglovaal”), and current drilling (2017 to present) by Orion
- Include reference to measures taken to ensure sample representivity Minerals Ltd (Orion).
and the appropriate calibration of any measurement tools or systems
Anglovaal:
used.
- For diamond drilling carried out by Anglovaal between 1968 and 1984,
- Aspects of the determination of mineralisation that are Material to the
there is limited information available on sampling techniques for core.
Public Report.
However, with exploration and resource management being carried out
- In cases where ‘industry standard’ work has been done this would be under the supervision of Anglovaal, it is considered by the Competent
relatively simple (e.g. ‘reverse circulation drilling was used to obtain 1 Person that there would be procedures in place to industry best practice
m samples from which 3 kg was pulverised to produce a 30 g charge standard at that time. This is based on the Competent Persons
for fire assay’). In other cases more explanation may be required, knowledge of exploration carried out by Anglovaal and discussions with
such as where there is coarse gold that has inherent sampling personnel employed by Anglovaal.
problems. Unusual commodities or mineralisation types (e.g.
- The exploration and resource management were under the professional
submarine nodules) may warrant disclosure of detailed information.
supervision of Dr Danie Krige an internationally recognised expert of the
time who published peer reviewed papers based on the sampling data.
The sampling was successful in defining a resource estimate which was
used as the basis of successful mine development and operation over a
20-year period.
- Drilling of the original surface exploration holes was carried out 200m –
250m line spacing. Underground exploration holes were not drilled on a
regular spacing.
- Surface drill exploration samples were all sent to Anglovaal Research
Laboratory at Rand Leases Mine and underground drill samples to the
mine laboratory for analyses.
- No records on the sampling methodology used are available.
Orion:
- Diamond core is cut at the core yard and half core is taken as the
sample.
- The core is sampled at 1m intervals where possible with sample lengths
adjusted to ensure samples do not cross geological boundaries or other
features.
- Drilling at the Deep Sulphide Target was carried out with the aim of
defining an approximate 60m x 60m pattern by use of “mother” holes
and deflections therefrom.
- Mineralised zones are drilled using core drilling.
- Sampling is carried out under supervision of a qualified geologist using
procedures outlined below including industry standard QA/QC.
- Samples submitted for analysis to ALS Chemex (Pty) Ltd (ALS) are
pulverised in its entirety at ALS and split to obtain a 0.2g sample for
digestion and analysis.
- Metallurgical samples were submitted to MINTEK for testwork and
analysis.
- Metallurgical samples were composited to form blends to allow
variability testing. The individual Hypogene (Deeps) variability drill core
samples were used to make-up the variability blend composites. The
individual variability drill core samples were stage crushed to 100%
passing 1.7mm, thoroughly blended and split into representative
subsamples by means of a rotary splitter. Variability blend composites
were produced by blending the required mass of each of the individual
drill core composites before blending and splitting into 1kg
representative subsamples by means of a rotary splitter.
- The Mintek analytical services division is ISO 17025 accredited and
runs a QA/QC program to verify the analysis precision and repeatability
using SARM control charts. All the samples are analysed with certified
reference material (CRM) with known values.
Drilling techniques - Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air Anglovaal:
blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, - Records for core size are not available.
triple or standard tube, depth of diamond tails, face-sampling bit or - No record on core orientation.
other type, whether core is oriented and if so, by what method, etc.).
Orion:
- Diamond core drilling using NQ and BQ sized core. BQ core was only
drilled where problems were encountered in the original NQ drilled drill
hole and the drilling could not continue with NQ size.
- In the near-surface weathered zone HQ core was drilled.
- Pre-collar drilled using percussion drilling on certain holes (above
mineralisation).
- Core was orientated in holes selected for geotechnical studies.
Drill sample - Method of recording and assessing core and chip sample recoveries Anglovaal:
recovery and results assessed. - All mineralised intersections were done with core drilling.
- Measures taken to maximise sample recovery and ensure - Core recoveries are documented on the assay sheets. Core recoveries
representative nature of the samples. were measured for each "run".
- Whether a relationship exists between sample recovery and grade - In most V holes and all D and F holes, intersections were in hard rock
and whether sample bias may have occurred due to preferential and recoveries were generally good through the mineralisation.
loss/gain of fine/coarse material.
Orion:
- All mineralised intersections are done with core drilling.
- Core stick-ups reflecting the depth of the drill hole are recorded at the
rig at the end of each core run.
- A block with the depth of the hole written on it is placed in the core box
at the end of each run.
- At the core yard, the length of core in the core box is measured for 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.
- Core recovery in all the mineralised intersections are good.
- No grade variation with recovery was noted.
Logging - Whether core and chip samples have been geologically and Anglovaal:
geotechnically logged to a level of detail to support appropriate - All relevant intersections for V surface holes have been geologically
Mineral Resource estimation, mining studies and metallurgical logged by qualified geologists and all of this information is available. It is
studies. understood from historical reports and discussions with Anglovaal
- Whether logging is qualitative or quantitative in nature. Core (or geologists involved with the Prieska Mine that all intersections for D and
costean, channel, etc.) photography. F holes were logged by qualified geologists. The detail logs are
- The total length and percentage of the relevant intersections logged. currently not available.
- Downhole geotechnical information is available for some of the D and F
holes only. Downhole mineralogical logs are available for some D and F
holes.
Orion:
- Pre-collar percussion holes are logged by qualified geologists on 1m
intervals using visual inspection of washed drill chips. A hand held XRF
instrument is used to determine the presence of any metals.
- Core of the entire hole length was geologically logged and recorded on
standardised log sheets by qualified geologists.
- Qualitative logging of colour, grain size, weathering, structural fabric,
lithology, alteration type and sulphide mineralogy carried out.
- Quantitative estimate of sulphide mineralogy.
- 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 Anglovaal:
techniques and taken. - Details of sub-sampling techniques not available.
sample preparation - If non-core, whether riffled, tube sampled, rotary split, etc. and - Although no formal QC samples were inserted by the geologists at the
whether sampled wet or dry. time of drilling the Anglovaal Research Laboratory produced their own
- For all sample types, the nature, quality and appropriateness of the standards, certified by other commercial laboratories which were
sample preparation technique. routinely inserted into batches at the laboratory. Duplicate samples
- Quality control procedures adopted for all sub-sampling stages to were also inserted to check for repeatability.
maximise representivity of samples.
- Measures taken to ensure that the sampling is representative of the in Orion:
situ material collected, including for instance results for field - Samples from percussion pre-collars are collected by spear sampling.
duplicate/second-half sampling. - Sampling on site aims to generate a < 2kg sub sample to enable the
- Whether sample sizes are appropriate to the grain size of the material entire sample to be pulverised without further splitting.
being sampled. - Water is used in the dust depression process during percussion drilling,
resulting in wet chip samples.
- BQ and NQ core cut at core yard and half core taken as sample.
- With core samples, the entire sample length is cut and sampled.
- Sample preparation is undertaken at ALS, an ISO accredited laboratory.
ALS utilises industry best practise for sample preparation for analysis,
involving drying of samples, crushing to <5mm if required and then
pulverising so that +85% of the sample passes 75 microns.
- CRMs, blanks and duplicates are inserted and analysed with each
batch. Insertion rates for the current reporting is: CRMs = 10%, blanks =
5% and field duplicates = 2%.
Quality of assay data - The nature, quality and appropriateness of the assaying and Anglovaal:
and laboratory tests laboratory procedures used and whether the technique is considered - Surface drill exploration samples were all sent to Anglovaal Research
partial or total. Laboratory at Rand Leases Mine.
- For geophysical tools, spectrometers, handheld XRF instruments, - Underground drill hole samples were sent to the mine laboratory, where
etc., the parameters used in determining the analysis including the same analytical method was used.
instrument make and model, reading times, calibrations factors - Atomic Adsorption method was used with a Nitric-bromide digest.
applied and their derivation, etc. Underground drill hole samples were sent to the mine laboratory, where
- Nature of quality control procedures adopted (e.g. standards, blanks, the same analytical method was used.
duplicates, external laboratory checks) and whether acceptable levels - Although no formal QC samples were inserted with the drill samples of
of accuracy (i.e. lack of bias) and precision have been established. the exploration holes the Anglovaal Research Laboratory developed
their own standards, certified by other commercial laboratories and
those were used internally in the laboratory. Duplicate samples were
also inserted to check for repeatability.
Orion:
- Samples submitted to ALS were analysed for base metals, Au and Ag.
Analysis was by the Inductively Coupled Plasma and Optical Emission
Spectroscopy ("ICP-OES") methodology, using a four-acid digest.
- External quality control of the laboratory assays is monitored by the
insertion of blanks and CRMs.
- CRM samples show high accuracy and tight precision with no
consistent bias.
- Blank samples indicate no contamination, within the pre-determined
thresholds, during the sample preparation process.
- Laboratory samples show excellent accuracy and precision.
- ALS has their own internal QC protocols which include CRMs (5%),
blanks (2.5%) and duplicates (2.5%).
- External laboratory checks have been carried out.
- Metallurgical samples submitted to MINTEK and ICP-OES methodology
applied for assaying.
- The Mintek analytical services division is ISO 17025 accredited and
runs a QA/QC program to verify the analysis precision and repeatability
using SARM control charts. All the samples are analysed with CRM with
known values.
Verification of - The verification of significant intersections by either independent or Anglovaal:
sampling and alternative company personnel. - No records available.
assaying - The use of twinned holes.
Orion:
- Documentation of primary data, data entry procedures, data
- The Competent Person is personally supervising the drilling and
verification, data storage (physical and electronic) protocols.
sampling along with a team of experienced geologists.
- Discuss any adjustment to assay data.
- The Competent Person reviewed the calculation of the significant
intersections.
- Twin holes are drilled to verify historical drill intersections (Anglovaal).
- For the EM survey, data are collected on site and validated by a
geophysical technician daily. Data (raw and processed) is sent to a
consultant geophysicist for review and quality control.
- No adjustments have been made to the assay data.
Location of data - Accuracy and quality of surveys used to locate drill holes (collar and Anglovaal:
points down-hole surveys), trenches, mine workings and other locations - All surface and underground hole collars were surveyed by qualified
used in Mineral Resource estimation. surveyors using a theodolite.
- Specification of the grid system used. - The historic mine survey data is in the old national Lo23 Clarke 1880
- Quality and adequacy of topographic control. coordinate system.
- Downhole surveys were carried out for most of the V holes and all of the
D and F holes. Methodology of the downhole surveys is not recorded on
the available hardcopy information but plans and sections are
meticulously plotted and signed off by a certified surveyor.
- Both Eastman and Sperry Sun instruments were used in the downhole
surveys.
- Significant deflections in the dips of the holes have been noted,
especially for the deeper holes. V holes with no downhole surveys are
shallower holes drilled earlier on in the initial exploration phase. These
holes intersected areas where the mineralisation is now largely mined
out.
- All hole positions have been converted to Lo23 WGS84 coordinates.
- Underground D and F holes are recorded in local "V" line and "O"
distance coordinates with local mine datum elevations. Level plans have
both the local V/O grid and Lo23 Clark 1880 grids plotted and this has
been used to define transformation parameters from local grid to
geographical coordinates. All hole positions have been converted to
Lo23 WGS84 coordinates.
Orion:
- Drill hole collar positions are laid out using a handheld GPS.
- After completion of the Orion drilling all collars were surveyed by a
qualified surveyor using a Trimble R8 differential GPS.
- Downhole surveys are completed using a North-Seeking Gyro
instrument.
- All survey data is in the WGS84 ellipsoid in the WG23 Zone with the
Hartebeeshoek 1994 Datum. The coordinates are also supplied in
Clarke 1880 and in UTM WGS84 Zone 34 (Southern Hemisphere).
Data spacing and - Data spacing for reporting of Exploration Results. Anglovaal:
distribution - Whether the data spacing and distribution is sufficient to establish the - Original exploration holes (V) were drilled on 200m - 250m spacing.
degree of geological and grade continuity appropriate for the Mineral - Underground drilled holes (D, F and R) were not drilled on a regular
Resource and Ore Reserve estimation procedure(s) and spaced grid.
classifications applied.
Orion:
- Whether sample compositing has been applied.
- At the Deep Sulphide Target drill holes aim to intersect mineralisation
on spacings sufficient to establish geological and grade continuity
appropriate for Mineral Resource and Ore Reserve estimations.
- Variography studies were carried out on both the historic and Orion data
set to determine the drill spacing for Mineral Resource estimates.
- No sample compositing was applied.
Orientation of data - Whether the orientation of sampling achieves unbiased sampling of - Historical and current drilling is oriented perpendicular, or at a maximum
in relation to possible structures and the extent to which this is known, considering achievable angle to, 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 - No sampling bias is anticipated as a result of hole orientations.
sampling bias, this should be assessed and reported if material. - EM surveys by Orion were completed in an orientation perpendicular to
the interpreted or intersected mineralisation.
Sample security - The measures taken to ensure sample security. Anglovaal:
- No details of sample security available. However, during the mining
operations the site was fenced and gated with security personnel
employed as part of the staff.
Orion:
- Chain of custody is managed throughout, and the policy managed
through an appropriate SOP. Samples are stored on site in a secure
locked building and then freighted directly to the laboratory.
Audits or reviews - The results of any audits or reviews of sampling techniques and data. Anglovaal:
- No records available.
Orion:
- SRK Consulting has carried out a review on the sampling techniques
and data.
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 Rights are held by Repli Trading No 27 (Pty) Ltd and
and land tenure agreements or material issues with third parties such as joint Vardocube (Pty) Ltd, which are subsidiaries of Orion.
status ventures, partnerships, overriding royalties, native title interests, - The Prospecting Right areas covers a strike of 2460m for the Deep
historical sites, wilderness or national park and environmental Sulphide mineralisation.
settings. - All of the required shaft infrastructure and lateral access underground
- The security of the tenure held at the time of reporting along with any development is available within the two Prospecting Rights.
known impediments to obtaining a licence to operate in the area.
Exploration done by - Acknowledgment and appraisal of exploration by other parties. - All exploration and life of mine drilling (V, D and F holes) was done by
other parties Anglovaal, resulting in a substantial amount of hard copy data from
which Orion has been able to assess the prospectivity of the remaining
mineralisation.
- The Anglovaal exploration resulted in the delineation and development
of a large mine.
- Metallurgical testwork was supervised by DRA Projects South Africa
(Pty) Ltd (DRA) and most of the laboratory work conducted by MINTEK
in their Johannesburg laboratories, South Africa.
Geology - Deposit type, geological setting and style of mineralisation. - The Copperton deposit is a Volcanogenic Massive Sulphide (VMS)
deposit which is situated in the southernmost exposures of the north-
northwest trending Kakamas Terrain, which forms part of the Mid-
Proterozoic Namaqualand Metamorphic Complex.
- The deposit is hosted by the Copperton Formation of the Areachap
Group. The Areachap Group, also hosts several other but smaller VMS
deposits such as the Areachap, Boks Puts, Kantien Pan, Kielder, and
Annex Vogelstruisbult deposits.
- The structural sequence at the mine consists of a footwall Smouspan
Gneiss Member, Prieska Copper Mines Assemblage (PCMA), which
hosts the sulphide mineralisation, and the hangingwall Vogelstruisbult
Gneiss Member.
- The historically mined section of the deposit is confined to a tabular,
stratabound horizon in the northern limb of a refolded recumbent
synform, the axis of which plunges at approximately 5° to the south-
east.
- The mineralised zone outcrop has a strike of 2400m, is oxidised and / or
affected by leached and supergene enrichment to a depth of
approximately 100m and crops out 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. Current drilling indicates that the Deep Sulphides has
a strike length of at least 2860m in depth.
- The thickness of the mineralised zone exceeds 30m in places but
averages between 7m and 9m. The mineralised zone persists to a
depth of 1100m (as deep as 1228m in one section) after which it is
upturned due to the folding.
- The Deep Sulphide Target area located below the historical mined area,
comprises the steep down dip continuity ("steep limb and hinge zone”)
and from where it upturns to its subsequent synformal structure ("trough
zone").
- The morphology of the mineralised horizon in the eastern limb is well
mapped out by drilling and historic mining while the western limb up dip
extent is poorly tested and mapped.
Drill hole - A summary of all information material to the understanding of the - Drill hole collar coordinates, elevation, inclination and azimuth, down
Information exploration results including a tabulation of the following information hole length, interception depth and hole length are available in Orion’s
for all Material drill holes: geological database and are not included in this release.
o easting and northing of the drill hole collar - The significant mineralised intersections and the easting and northing of
o elevation or RL (Reduced Level – elevation above sea level in these mineralised intercepts are presented in prior releases.
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, - Significant Intersections for the Deep Sulphide Target are calculated by
methods maximum and/or minimum grade truncations (e.g. cutting of high average of assays result > 0.3% copper or 0.5% zinc and weighted by
grades) and cut-off grades are usually Material and should be stated. the sample width and specific gravity of each sample.
- Where aggregate intercepts incorporate short lengths of high grade - Significant Intersections for the +105 Level Target are calculated by
results and longer lengths of low grade results, the procedure used average of assays result > 0.3% copper or 0.5% zinc and weighted by
for such aggregation should be stated and some typical examples of the sample width of each sample only.
such aggregations should be shown in detail. - In general, the significant intersections correspond strongly to
- The assumptions used for any reporting of metal equivalent values geological boundaries (massive sulphides) and are clearly
should be clearly stated. distinguishable from country rock / surrounding samples.
- No truncations have been applied at this stage for either Target.
- Metallurgical samples were composited to form blends for variability
testing.
Relationship - These relationships are particularly important in the reporting of - Most holes intersected the mineralisation perpendicular or at high angle
between Exploration Results. to the attitude of the mineralisation.
mineralisation - If the geometry of the mineralisation with respect to the drill hole - The geometry of the Deep Sulphide mineralisation is complex and true
widths and intercept angle is known, its nature should be reported. widths can only be obtained from the three-dimensional wireframe
lengths - If it is not known and only the down hole lengths are reported, there created of the mineralisation.
should be a clear statement to this effect (e.g. ‘down hole length, true - Mineralisation widths have been reported in previous reports.
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 release 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 metallurgical test results referred to in the release are listed in
practicable, representative reporting of both low and high grades Tables 1,2 and 4. All other metallurgical and drill hole information have
and/or widths should be practiced to avoid misleading reporting of been detailed in previous releases as referred to in the text.
Exploration Results. - The Company has presented all available information in this report in a
balanced manner and has provided appropriate context for the
Exploration Results to allow a considered and balanced judgement of
their significance.
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 - The nature and scale of planned further work (e.g. tests for lateral - Further metallurgical testwork is on-going as part of the feasibility study.
extensions or depth extensions or large-scale step-out drilling). - Plan showing drill hole intersections for metallurgical testwork sample
- Diagrams clearly highlighting the areas of possible extensions, collection is included.
including the main geological interpretations and future drilling areas, - List of drill hole identification data for metallurgical samples drill holes is
provided this information is not commercially sensitive. included
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