Wrap Text
Scoping Study Confirms a Robust Phase 1 for 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”)
SCOPING STUDY CONFIRMS A ROBUST PHASE 1 FOR THE PRIESKA ZINC-COPPER PROJECT
Orion Minerals Ltd (ASX/JSE: ORN) (Orion or Company) is pleased to present the outcomes of a scoping study,
based on recently updated Mineral Resources, for its Prieska Zinc-Copper Project (Prieska Project or Project),
located in the Northern Cape Province of South Africa (Scoping Study or Study).
The Study confirms the potential for the Prieska Project to become a significant near-term, low-cost, zinc and
copper concentrate producer, whilst laying the foundations for future opportunities. Based on Study
assumptions, the Project would provide excellent financial returns, for modest capital investment given the
scale of operations envisaged.
Presented in compliance with ASX Listing Rules for Release of Scoping Study outcomes:
The Study referred to in this announcement is a technical and economic investigation of the viability of the
Prieska Zinc-Copper Project. It is based on low-level accuracy technical and economic assessments (± 35%
accuracy) and is insufficient to support estimation of Ore Reserves, to provide assurance of an economic
development case at this stage or to provide certainty that the conclusions of the Study will be realised. The
Scoping Study is based on the material assumptions outlined in this report. The Production Target and forecast
financial information referred to in this technical document is based on JORC (2012) Mineral Resources which
are reported and classified at approximately 64% Indicated and 36% Inferred. There is a low level of geological
confidence associated with Inferred Mineral Resources and there is no certainty that further exploration work
will result in the determination of additional Indicated Mineral Resources or that the Production Target itself will
be realised. Further evaluation work in the form of a Feasibility Study is ongoing. To achieve the outcomes
specified in this Study initial funding in the order of AUD 300 million to AUD 330 million (including a 20%
contingency) is likely to be required. Investors should note that there is no certainty that Orion will be able to
raise funding when needed. It is also possible funding may only be available on terms that may be dilutive to or
otherwise effect the value of Orion’s shares.
Orion’s Managing Director and CEO, Errol Smart, commented:
“We are very pleased to have completed our Resource upgrade that has confirmed what an exceptional
deposit we have at Prieska. With nearly two-thirds of the Resource now in the Indicated category, we can
present the case for the first ten years of a very attractive mining operation. The Study indicates solid operating
margins, with the peak funding of AUD 320m inclusive of 20% contingency, recovered within the first third of
mine life all supported by current Indicated Resources yielding an NPV of AUD 420m.
The Study identifies important opportunities for further financial upside, both from extending the life of mine,
and from optimising the grade of extraction following further drilling to be conducted from underground. The
current Phase 1 Study has examined extracting only 75% of the total Mineral Resource at the mean Mineral
Resource grade.
The application of further modernisation, making optimised use of low-cost available renewable energy, also
provides an important cost saving opportunity being investigated in depth by the Bankable Feasibility Study
which is well advanced.”
KEY SCOPING STUDY RESULTS
Initial 10-year mining scenario supported by 64% of Indicated Mineral Resources, extracting 75% of a
combined underground Mineral Resource of 28.73Mt at 3.77% zinc and 1.16% copper.
2.4Mtpa operation, producing about 70kt to 80kt of zinc and 22kt of copper in concentrates per annum.
43% all-in-sustaining margin, with all-in-unit costs of AUD 1,701/t (USD 1,215/t) zinc equivalent metal sold.
Estimated AUD 130m annual free cash flow after-tax at steady-state.
AUD 400m to AUD 440m pre-tax NPV at 12.5% discount rate and approximately 38% pre-tax IRR.
Payback period of less than 3 years from first production.
Approximately AUD 300m to AUD 330m peak funding to setup the infrastructural foundation for future
expansion.
Bankable Feasibility Study due for completion in Q2 2019.
Estimated Estimated
Price and FX Assumptions Unit Financial Performance Unit
Value Value
Metal price – Cu (USD3.00/lb) USD/t 6,6141 NPV (pre-tax) @12.5% discount rate AUD m 400 – 440
Metal price – Zn (USD1.30/lb) USD/t 2,8661 IRR (pre-tax) % 38%
Exchange rate ZAR:USD 14 : 1 Payback from first production years 3
Exchange rate ZAR:AUD 10 : 1 Undiscounted free cash flow (pre-tax) AUD bn 1.2 – 1.3
Exchange rate AUD:USD 1.4 : 1 Peak funding AUD m 300 – 330
Estimated Estimated
Production Metrics Unit Project Cost Metrics Unit
Value Value
Life of Mine (Phase 1) years 10 Average cash operating unit cost (C1) AUD/t 83
Treatment plant capacity ktpa 2,400 All-in-sustaining cost per unit ROM t AUD/t 100
Phase 1 tonnage - ROM mt 22 All-in-sustaining cost per unit Zn eq t sold AUD/t Zn 1,701
Phase 1 tonnage - processed mt 22 All-in-sustaining cost per unit Cu eq t sold AUD/t Cu 4,949
Concentrate tonnage - Zn mt 1.4 Price received (net of NSR) - Zn AUD/t Zn 2,982
Concentrate tonnage - Cu mt 0.9 Price received (net of NSR) - Cu AUD/t Cu 8,677
Concentrate grade - Zn % 50.0% All-in-sustaining margin % 43%
Concentrate grade - Cu % 24.0% Operating breakeven grade (Zn eq) % 4.1%
NSR as % of metal price - Zn % 74.3%
Estimated
NSR as % of metal price - Cu % 93.7% Project Cash Flows Unit
Value
Metal sold (in concentrates) - Zn kt 686 LoM net revenue AUD m 3,457
Metal sold (in concentrates) - Cu kt 206 LoM operating costs AUD m 1,740
Total sales as Zn equivalent kt 1,285 Project start-up capital expenditure AUD m 360 - 390
Total sales as Cu equivalent kt 442 Sustaining capital expenditure AUD m 65 - 75
Table 1: Key Scoping Study Results for Phase 1 of the Prieska Zinc-Copper Project. Note that the overall Study accuracy level is ±35%.
The Scoping Study investigated the economic viability of an initial ten-year phase of exploitation of the Prieska
deposit. This initial phase will involve underground mining to extract portions of the delineated Mineral
1 Guided by Afriforesight (Pty) Ltd long-term consensus forecast as of August 2018.
Resources (refer ASX release 18 December 2018). A Bankable Feasibility Study (BFS) is well advanced and due
for completion in Q2 2019.
Phase 1 of the Project has a potential Net Present Value (NPV) of between AUD 400m and AUD 440m pre-tax
and post-royalties (AUD 280m to AUD 310m, post-tax, post royalties), using non-inflation-adjusted estimates and
a discount rate of 12.5%, and would achieve a pre-tax Internal Rate of Return (IRR) of 38%. The NPV is based
on long-term forecast metal prices of USD 1.30/lb (USD 2,866/tonne) for zinc and USD 3.00/lb (USD 6,614/tonne)
for copper. Peak funding requirements would amount to between AUD 300m to AUD 330m including a 20%
contingency allowance. This would occur in the third year of the capital expenditure (CAPEX) program.
Payback would occur about 5 years from the start of construction or about 3 years from the start of production.
Unit all-in-sustaining costs (AISC) over the duration of Phase 1 would be approximately AUD 1,701/t (USD
1,215/t) zinc equivalent metal sold. The realised price (net of smelter charges) would be AUD 2,982/t (USD
2,130/t) zinc equivalent sold, yielding in the order of 43% in all-in-sustaining margin. Operating break-even
grade is estimated at 4.1% zinc equivalent, well below the Mineral Resources grade of 6.9% zinc equivalent [Zn
eq grade = Zn grade + 2.91 x Cu grade] 2, applied in the production schedule.
The NPV estimate is most sensitive to the ZAR-USD exchange rate. Pre-tax NPV ranges from AUD 250m to AUD
550m as the ZAR-USD exchange rate varies from -15% to +15% of the base case assumptions.
PRIESKA SCOPING STUDY TECHNICAL REPORT EXTRACTS
Nature of and Contributions to the Scoping Study
The Scoping Study is based on work carried out by Orion, DRA Projects SA (Pty) Ltd (DRA), Fraser McGill (Pty)
Ltd, METC Engineering (Pty) Ltd, Precision Capital Development Services (Pty) Ltd, Bluhm Burton Engineering
(Pty) Ltd, METS South Africa (Pty) Ltd, ABS Africa (Pty) Ltd, Z* Star Mineral Resource Consultants (Pty) Ltd and the
MSA Group (Pty) Ltd. References are also made to historical and other more current Project documents.
The Scoping Study aims to consolidate the learnings from the various studies conducted on the Project and to
inform the ongoing BFS. The report complies with Australian Securities Exchange (ASX) listing rules and
Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC (2012))
reporting standards.
Project Context and Overview
Overview
The Project is located in the Northern Cape Province of South Africa. Figure 1 outlines the area of the
Company’s exploration activities, with the Project located at the southern extent, approximately 60km south-
west of the town of Prieska.
As part of the Project, a Scoping Study has been completed and a BFS is underway to evaluate establishing
new mining operations at the Prieska Copper Mine (PCM) which has been closed since 1991. The mine was
previously owned and operated by Prieska Copper Mine Limited, a subsidiary of Anglo-Transvaal Consolidated
Investment Company Limited (Anglovaal).
2 Refer to page 16 for Zn equivalent grade assumptions.
Figure 1: Location of the Prieska Zinc-Copper Project, Northern Cape Province, South Africa.
The Scoping Study, as summarised herein, was carried out to an accuracy level of ± 35% and is supported by
JORC-compliant Mineral Resources as announced in December 2018 (refer ASX release 18 December 2018). In
the Study, a mining scenario was assessed which covers the initial 10-year phase of operations, using
underground mining methods (Phase 1). Phase 1 excludes any open pit mining, historical pillar extraction and
does not exhaust all known deposit extensions. Project financial evaluations have thus been limited to
considering Phase 1 only.
Ownership and Mineral Tenements
Orion completed the acquisition of Agama Exploration and Mining (Pty) Ltd (Agama) and its subsidiaries in
March 2017. Orion now holds, through Agama’s subsidiary companies, a 73.3% interest in the Repli Prospecting
Right (Repli) and a 70% interest in the Vardocube Prospecting Right (Vardocube), which together cover an
area of 6,766 hectares that encompasses the historic PCM, Figure 2. The remaining project interests are held by
various Black Economic Empowerment (BEE) entities, in compliance with South African legislation. According to
the South African Department of Land Restitution and Reform, there are no land claims on any of the
properties covered by the prospecting rights.
Applications to obtain the rights to mine the Repli prospecting right area were lodged in April 2018. These
applications include a Mining Work Program (MWP), Environmental Authorisation (EA), Integrated Water and
Waste Management Plan (IWWMP) and a Social and Labour Plan (SLP). Vardocube Mining Right applications
were submitted in September 2018. Granting of the Repli Mining Right, along with associated environmental,
water and waste management permitting, is expected in Q3 2019, with granting of the Vardocube Mining
Right expected soon thereafter. This would enable construction activities to commence in calendar year 2019,
subject to a positive BFS and the availability of funding. Other required land access rights have already been
obtained through agreements negotiated with affected landowners and occupiers. Orion also holds other
neighbouring prospecting rights granted to Repli and another Orion subsidiary, Bartotrax (Pty) Ltd (Bartotrax),
Figure 2. These enable extensional exploration to continue delineating the dip and strike extensions beyond
the Phase 1 footprint of the Prieska deposit, as well as conduct exploration for satellite deposits.
Figure 2: Mineral Tenement Map for the Project Area.
History
PCM operated from 1971 until 1991. During this time, the mine processed 45Mt of run-of-mine (ROM) material
and produced 1.01Mt of zinc and 0.43Mt of copper as high-grade concentrates, whilst achieving average
processing plant recoveries of 84.3% for zinc and 84.9% for copper, (refer ASX release 15 November 2017).
Reported ‘mineral reserve’ grades at the time the original mine was commissioned were 3.8% zinc and 1.7%
copper3. Pyrite was also intermittently produced as a by-product. The concentrates were sent to either O'kiep
or Zincor for smelting or Saldanha Bay for export.
Existing infrastructure
Some of the infrastructure that serviced previous mining operations is still serviceable and can be used for the
new Project. This infrastructure includes a 60km-long bulk water supply pipeline transferring water from the
Orange River, tarred roads, regional grid power and an airstrip. The town of Copperton, which is located 4km
by road from the main rock hoisting shaft, used to be the principal residence for the PCM community. The
town is still in use, though only 40 of the original 300 houses remain. The farming service town of Prieska, with a
population of 14,000, lies 60km north-east of the Project site via the tarred R357 regional highway.
3 Note that these were historical estimates not compliant to JORC-Code reporting standards.
The main hoisting shaft, which is 1,024m deep, and its associated concrete headgear, are intact and re-
useable. Some 37km of underground tunnels and mined-out stopes are currently flooded to a depth of 330m
below surface and so an 18-month pumping program would be required to de-water these workings.
Geology, Exploration and Mineral Resources
Project Geology
The Prieska deposit is a Volcanogenic Massive Sulphide (VMS) body 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 smaller VMS deposits such as the Areachap, Boks Puts, Kantien Pan,
Kielder, and Annex Vogelstruisbult deposits. The structural sequence at the deposit consist of a footwall
Smouspan Gneiss Member, the Prieska Copper Mines Assemblage (PCMA), which hosts the sulphide
mineralisation, and the hangingwall Vogelstruisbult Gneiss Member, Figure 3. 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 outcrop of the mineralised zone has a strike of 2,400m, is oxidised and / or affected by leached and
supergene enrichment to a depth of approximately 100m. 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, at depth, the Deep Sulphide Zone
has a strike length of at least 2,860m. The thickness of the mineralised zone exceeds 30m in places but
averages between 7m and 9m. The mineralised zone persists to a depth of 1,100m (as deep as 1,228m in one
section) after which it is upturned due to the folding.
The Deep Sulphide Zone, located below the mined-out areas, comprises the steep, down dip continuity, then
upturns to its synformal structure, Figure 3 and Figure 4. The morphology of the mineralised horizon in the
eastern limb is well mapped out by drilling and historical mining while the western limb up-dip extent is poorly
tested and mapped.
The +105 Level Resource area comprises the oxide / supergene / mixed zone / primary sulphide gradation
profile situated from above the upper limit of mining at approximately 100m depth below surface, up to
surface. This zone has a strike length of 867m, Figure 4.
Figure 3: Surface plan and cross-section showing the interpreted strike and dip extents of the known Prieska Deposit (modified after Theart, et.
al, 1989 and Wagner and Van Schalkwyk, 1986).
Figure 4: Longitudinal section of the Prieska Project showing the positions of the Mineral Resources.
Exploration
Orion’s approach to defining the Mineral Resources for the Project was to initially use infill and verification
drilling campaigns from surface. These drilling campaigns targeted the historically-drilled and identified
mineralised areas and aimed to delineate sufficient Mineral Resources to motivate an initial phase of mining
operations. On re-establishing deep underground access, follow-up extensional exploration and infill drilling
programs would be conducted from more advantageous drill platforms located underground. This approach
allows for more cost-effective and efficient delineation and upgrading of the sparsely drilled strike and dip
extents of the deposit. The latest surface-based drilling campaign was completed in October 2018,
culminating in Orion having drilled approximately 85km using predominantly diamond coring drill rigs (refer ASX
release 15 October 2018).
Surface-based exploration work, to delineate the strike and dip extents of the Deep Sulphide Zone continues,
with downhole EM and SkyTEMTM campaigns in progress and more planned.
Mineral Resources
Total delineated Deep Sulphides Mineral Resources classified and reported in terms of JORC (2012) are 28.73
million tonnes grading 3.77% zinc and 1.16% copper, refer to Table 2. The Mineral Resources comprise of:
• Indicated Mineral Resources amounting to 18.51 million tonnes and grading 3.60% zinc and 1.17%
copper4 (refer ASX release 18 December 2018); and
• Inferred Mineral Resources, amounting to 10.22 million tonnes and grading 4.08% zinc and 1.14%
copper4 (refer ASX release 18 December 2018).
4Mineral Resource reported in ASX release of 18 December 2018: “Landmark Resource Upgrade Sets Strong Foundation” available to the public on
www.orionminerals.com.au/investors/market-news. Competent Person Orion’s exploration: Mr. Pottie Potgieter. Competent Person: Orion’s Mineral Resource:
Mr. Sean Duggan. Orion is not aware of any new information or data that materially affects the information included above. For the Mineral Resources, the
company confirms that all material assumptions and technical parameters underpinning the estimates in the ASX release of 18 December 2018 continue to
apply and have not materially changed. Orion confirms that the form and context in which the Competent Person’s findings are presented here have not
materially changed.
The Deep Sulphide Mineral Resources were modelled based on a 3% to 4% Zn equivalent [Zn Eq = Zn% + (Cu% x
2)] threshold range to constrain the mineralisation. All mineralisation within the modelled boundaries has been
reported.
Volume Density Cu
License Classification Tonnes Zn (tonnes) Zn (%) Cu (%)
(m3) (tonnes/m3) (tonnes)
Indicated 4,414,000 3.41 15,052,000 510,000 3.38 170,000 1.15
Repli Inferred 2,044,000 3.42 6,998,000 270,000 3.86 80,000 1.09
Total 6,458,000 3.41 22,050,000 779,000 3.53 249,000 1.13
Indicated 1,018,000 3.39 3,455,000 158,000 4.57 44,000 1.27
Vardocube Inferred 933,000 3.45 3,221,000 147,000 4.56 41,000 1.27
Total 1,951,000 3.42 6,676,000 305,000 4.57 85,000 1.27
Indicated 5,432,000 3.41 18,507,000 667,000 3.60 217,000 1.17
Deep
Inferred 2,977,000 3.43 10,219,000 417,000 4.08 117,000 1.14
Sulphide Total
Total 8,409,000 3.42 28,726,000 1,084,000 3.77 334,000 1.16
Rounding, as required by reporting guidelines, may result in apparent differences between tonnes, grades and contained metal content.
Table 2: Mineral Resource Estimate for the Prieska Zinc-Copper Project.
Mining Operations
Mining Methods and Layouts
Tunnel development established during previous operations allows for early access to underground production
areas. Phase 1 layouts extend approximately 600m down-dip of existing workings in the north-west section of
the deposit and some 250m down-dip of existing workings in the south-eastern section of the deposit, Figure 5.
Figure 5: Isometric View of the Conceptual Deep Sulphide Zone Underground Design Layout.
Whilst access development layouts were considered with the whole Phase 1 in mind, the layouts allow the
zones of Indicated Mineral Resources to be prioritised for mining, whilst upgrading of Inferred Resources is
completed by infill drilling from underground. Indicated Mineral Resources are contiguous across large areas
allowing efficient mining, Figures 6 and 7.
Figure 6: Isometric View of the Deep Sulphide Zone showing the distribution of Indicated and Inferred Zones. The contiguous nature of
Indicated Mineral Resources is highlighted.
Figure 7: Isometric View of the Deep Sulphide Zone showing contiguous nature of Indicated Mineral Resources.
A combination of longhole stoping with paste fill (LHSF) and Drift-and-Fill mining with paste fill have been
selected as the preferred mining methods. Generally, LHSF would predominate in the steeper sections of the
mining area and Drift-and-Fill would be employed in the flatter dipping areas. Longhole open stoping (LHOS)
was successfully employed during historical operations down to an approximate depth of 900m below surface.
Using paste fill, as well as Drift-and-Fill methods would cater for mining at greater depths and would
accommodate the changing dip of the deposit. These methods would also allow increasing the mining
extraction ratio compared to historical mining. Other improvements on historical mining practices would be
the use of a more technologically-advanced mining fleet to provide faster tunnel development and more
accurate production drilling. Layouts and sequencing would be formulated to reduce the need for rib and sill
pillars, resulting in mining extraction ratios of between 75% to 80% being achievable.
LHSF would be applied in both a transverse or longitudinal orientation, depending on the shape and width of
the mineralisation. Typically stope widths would range between 5m to 20m, with strike spans of a maximum of
60m. Inter-level spacings were designed at 20m.
Approximately 65% of monthly production would come from LHSF (130,000 tonnes) and 35% (70,000 tonnes)
from Drift-and-Fill mining. LHSF stope capacities range from 26,000 tonnes to 52,000 tonnes per stope. This
indicated that three to five stopes would need to be extracted each month to meet the required monthly LHSF
production volumes. Five to seven stopes would be kept in production, ready for blasting, at any one time as a
contingency measure.
Underground Mining Fleet
Underground development and production operations are planned to be fully mechanised, with all
development headings being advanced using twin boom jumbos and supported using bolting rigs. Load-haul
dump units (LHDs) would be used to load blasted development and production rock into ore passes in the
upper levels and into a truck fleet, which would haul up 1 in 7-inclined roadways to the central crusher
location, the excavations of which already exist. Rock is planned to be hoisted to surface via the Hutchings
Shaft, using existing skip-loading chambers already excavated below the 957 level. New crushing, conveying
and skip-loading plant would need to be installed.
The underground mining fleet has been selected assuming mechanical availability of 90% for all mobile
equipment, Table 3. The use of electric-drive and automated vehicles is being investigated as part of the BFS
and may present significant efficiency, safety and health and cost improvement opportunities.
Units Quantity Units Quantity
Drill Rigs Utility Vehicles
Development Drilling Rig 3 Development Scissor lift 2
LHSF Drilling Rig 3 Production Scissor lift 2
Drift-and-Fill Drilling Rig 4 LHSF Explosives Charging Unit 2
10 Dev Explosives Charging Unit 2
Bolters Men Transporter (cassettes) 2
Waste Development Bolter 2 10
Production Development Bolter 2 General and Supervision Vehicles
4 Development Supervision Vehicle 2
Underground Trucks Production Supervision Vehicle 3
Development Truck (40t) 4 Scissor Lift UV 2
Production Truck (40t) 5 Shotcreter 2
9 Agi cars (shotcrete) 1
LHD Units Mobile Crane 1
Waste development (12t) 3 Grader (UG) 1
Production LHD (14t) 4 Scaler 3
7 15
Total underground mobile units 55
Table 3: Underground Mining Fleet for the Prieska Zinc-Copper Project.
Underground Crushing and Hoisting
The existing crusher chamber would be rehabilitated and re-equipped, Figure 8. Crushed rock, at -140mm,
would then be discharged via two vibrating feeders onto two skip-loading flask conveyors. The loading flasks
would be located on the 957m level.
Figure 8: Crusher and Shaft Loading Arrangement – existing excavations.
The main shaft would be equipped with a rock hoisting capacity of 2.4Mtpa, utilising two 14-tonne skips with a
hoisting speed of 12m/s. A Koepe winder would be used for rock hoisting and would have a power rating of
approximately 1.8 MW. A ground-mounted double-drum, 4.9m-diameter winder would be used for the men-
and-materials cage which would have an estimated power rating of 2.7 MW. Scope exists for centralised
control and automation of processes within the crushing and hoisting functions being assessed as part of the
BFS.
Geotechnical Investigations
Observations from the existing tunnels in the upper levels of the historical mine indicate very competent rock
and very little tunnel support was previously installed. Localised roof-bolting was carried out in isolated areas
where small amounts of fracturing was observed.
Eight geotechnical drill holes provided test samples for 30 compressive and tensile strength tests, culminating in
the determination of Rock Quality Designations (RQD), Geological Strength Indices (GSI), Rock Mass Ratings
(RMR) and Q Index ratings (Q) for the areas targeted for development. The results confirm competent ground
conditions are to be expected and commensurate stope spans and support regimes have been assumed,
Table 4.
Average compressive Average
Rock type RQD Min RMR Max RMR Q
strength (MPa) RMR
Hangingwall gneiss 89 312 82 67 97 21.7
Foot-wall gneiss 90 312 81 63 92 19.4
Mineralised zone 88 197 78 59 89 19.4
Table 4: Rock Quality Metrics for the Deep Sulphide Zone Rock Regime.
Back-fill Design
Paste back-fill has been selected as the most effective fill type for the LHSF and Drift-and-Fill areas. Plant
tailings would be used with cement at various mix ratios depending on the fill and strength requirement.
Development waste would also be used to back-fill stopes where possible. Test results show one assumed
design mix achieving 500kpa uniaxial compressive strength after 7 days for a 7% cement mix.
Ventilation Design
Based on the underground diesel-powered fleet selected, approximately 600m3/sec of ventilation would be
needed, using the legislated requirement of 0.06m3/sec/kW of engine rating and an estimated 8,000 kW
engine power rating for the truck and LHD units. To cater for other smaller mining vehicles, workshops and
crusher stations, ventilation losses and leakage, a total requirement of 0.1m 3/sec/kW for the rated engine
output was assumed. If electric vehicles are employed, then it is expected that significant reductions in
ventilation requirements may be expected due to reduced heat and exhaust fume loads. The option exists to
centrally control, monitor and automate the operation of key ventilation fans via fibre optic-linked remotely-
controlled systems.
The Hutchings Shaft and Main Decline would be used as the primary intakes. The Boehmke and Beecroft Shafts
would be refurbished as up-cast ventilation shafts. New ventilation fans would be erected on the upcast shaft
collars. Further capital is allowed for the deepening of both upcast shafts using raise-boring techniques.
Underground Workings Rehabilitation
The existing main decline from surface into the underground workings is an estimated 7.1km and a provision for
rehabilitation of 30% of the total decline length has been allowed for. Rehabilitation would consist of cleaning
and making areas safe and replacing missing or inadequate roof support. The same approach was followed
for the crusher-station, station breakaways, underground workshops, pump stations and refuge chambers.
Shaft and Winder Housing Refurbishment
Visual inspections, non-destructive testing and thickness testing was carried out on the main shaft’s steelwork
and the majority of steel is in good order. For Scoping Study purposes, it has been estimated that 30% of the
steelwork would need to be replaced.
The Koepe rock winder housing on top of the shaft was removed at mine closure and must be replaced, along
with the installation of a new Koepe winder. A new winder room and a double-drum, ground-mounted, men-
and-materials winder would also be installed. It is intended to source a refurbished winder on the second-hand
market. There are a relatively large number of suitable winders available on the local market due to the recent
closure of gold and platinum mines. Assumed second hand winder costs were used for the Scoping Study.
New winder automation systems, conveyances, counterweights with all the required attachments, sheaves
and ropes have been provisioned for installation with the respective winders. This function will be automated.
Dewatering of Underground Workings
The Hutchings Shaft and underground workings are currently flooded with water to a depth of 330m below
surface. The water has accumulated over a 26-year period and is estimated at a volume of 8 to 10 million m3.
This accumulated water would be pumped out, over an 18-month period, using a system of cascading
submersible pumps lowered into the shaft barrel with multi-stage centrifugal pumps established in existing
pump chambers adjacent to the shaft barrel.
A separate mud pumping system is planned to be temporarily installed from the 957 level to the 720 level
settlers. Dewatering between the 957 level and the shaft-bottom would be done using submersible slurry
pumps as it is anticipated that the water at these levels will be muddy.
All pumped water would report to a 1 million m3 capacity, lined, dewatering dam on surface, where the water
would be evaporated, using a combination of natural and mechanically-assisted evaporation. This method of
using evaporators is in wide use globally as a means of accelerating the disposal of excess water. Evaporation
of excess water is expected to be particularly efficient at Prieska due to very high natural evaporation rates
exceeding 2,700mmpa.
Hydrogeology and Pumping
Historically the underground workings were exceptionally dry, with no significant groundwater inflows being
recorded. This has been borne out by recently compiled ground water models. Hence, the underground
pumping system has been designed to cope with a 1:50-year storm event, which could be 127mm in 24 hours
or 26.7 million litres over 24 hours.
Cut-off Grade and Metal Equivalent Estimation
To estimate an economic cut-off grade for planning purposes, a break-even grade was estimated at 4.1% zinc
equivalent, using assumptions as shown in Table 5.
Zn break-even cut-off grade Units Value
Cash operating cost per tonne treated AUD/t 83
Foreign currency exchange rates ZAR:AUD:USD 14 : 1.4 : 1
On-mine cash operating cost per tonne treated USD/t 59
Transport cost per tonne treated USD/t 12
Total cash operating cost per tonne treated USD/t 71
Metal price – zinc USD/t 2,866
Net smelter return (NSR) – zinc % price 74.3%
Net metal price received – zinc USD/t 2,130
Mining dilution 5%
Plant recovery factor (PRF) – zinc 85%
Break-even cut-off in-situ zinc grade 4.1%
Table 5: Underground Break-even Cut-off Grade Estimate5
The metal zinc equivalent grade was estimated as follows:
1% Cu = (Cu price x Cu NSR6) x (Cu PRF)
(Zn price x Zn NSR6) (Zn PRF)
= (6,6147 x 93.7%) x 85%
(2,8667x 74.3%) 85%
= 2.91% Zn
Therefore, Zn equivalent grade = [Zn grade + (2.91 x Cu grade)].
Mining Schedule and Modifying Factors
Underground mining access would be established 24 months after project commencement, with initial mining
targeting the upper levels, whilst shaft refurbishment is being completed lower down the shaft. Build up to full-
scale production would take 15 to 18 months to reach the steady-state output of 2.4Mtpa of ROM material
processed and would be scheduled to run for ten years. Mining production operations would be carried out
on a continuous roster, 24-hours a day, 7-days a week, using a 12-hour shift. Owner-mining has been assumed
as the base case operating philosophy.
5 Referenced in JORC Table
6 Refer Table 9.
7 Guided by Afriforesight (Pty) Ltd long-term consensus forecast as of August 2018.
Preliminary mine stope layouts were designed using the Mineral Resource model reported in April 2018 utilising
Mine Shape Optimiser (MSO) Datamine© Software and estimated modifying factors. Calculated break-even
cut-off grades and planned stope dimensions were used as inputs in order to derive estimated dilution and
economic stope limits. Assumptions were then made for geological and pillars losses, as well as mining
recovery as shown below, Table 6.
Parameter Source Tonnage Zn equivalent metal contained
Mineral Resources (below Cut-off: 4.5% Zn Eq.) Estimated 12% 8%
Mine design losses MSO 10% 11%
Design stope dilution MSO 10% n/a
Geological/pillar losses Assumed 5% 5%
Mining extraction factor (Mining recovery factor) Assumed 95% 95%
Table 6: Production Schedule Modifying Factors.
Applying the same modifying factors to the updated Mineral Resources resulted in the following proportions of
the Mineral Resources being used in the assumed production schedule, Table 7:
Proportion of Mineral Resources used in Conversion Ratio
Production Schedule (% of Resources)
Tonnage 78%
Metal Contained (zinc and copper) 75%
Table 7: Proportion of Mineral Resources used in the Conceptual Production Schedule.
The conceptual production profile is shown in Figure 9. It was assumed that the mining and treatment plant
feed schedules would be identical.
Figure 9: Conceptual Phase 1 Production Schedule.
The average ROM grades for the duration of Phase 1 are 3.7% zinc and 1.1% copper, with the average ROM
grades for the Indicated portion being 3.5% zinc and 1.1% copper and for the Inferred portion being 4.0% zinc
and 1.1% copper. Total production during Phase 1 would amount to approximately 22 million ROM tonnes.
Note that this production target includes 36% of Inferred Mineral Resources scheduled in the later years of the
Project. There is potential to significantly improve project returns by earlier scheduling of high grade zones of
the Inferred Resource. Additional drilling and optimising of the schedule would be required.
There is a low level of geological confidence associated with Inferred Mineral Resources and there is no
certainty that further exploration work will result in the determination of Indicated Mineral Resources or that the
Production Target referred to herein will be realised.
Mineral Processing
Metallurgical Testing
The metallurgical characteristics of the Deep Sulphide Zone are well known, given the long production history
from the deposit. Mine records show that over the 20-year mine life, average metal recoveries of
approximately 85% were achieved for both metals, (refer ASX release 15 November 2017). The metallurgical
test work program for the Project aimed to confirm the amenability of the Deep Sulphide Zone material to
conventional flotation as was previously used. The flowsheet tested incorporates crushing, milling and
sequential flotation stages to produce separated copper and zinc concentrates.
Approximately 800kg of mineralised hypogene samples from underground were collected from diamond drill
hole cores across the deposit. Bench-scale, lock-cycle metallurgical tests achieved targeted total metal
recoveries, ranging from 80% to 94% for zinc and 80% to 86% for copper into separated concentrates (refer ASX
releases 1 March and 12 June 2018).
The resultant concentrates had metal grades ranging between 45% and 54% for zinc and between 20% and
26% for copper in the respective products. Gold and silver reported to the copper concentrates at levels that
would qualify them as valuable by-products.
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.
Test results to date have generally equalled or exceeded the metal recoveries and concentrate grades
achieved during historical mining operations. Hence historical plant recoveries were assumed for the Scoping
Study.
Processing Plant Design
The proposed copper flowsheet has the following main processes:
• primary crushing;
• secondary crushing and screening followed by milling;
• a rougher flotation stage;
• re-grind of the rougher concentrate;
• a cleaner flotation stage;
• a re-cleaner flotation stage to produce a copper concentrate.
The zinc recovery section of the plant would start from the copper rougher tails and would have the following
main processes:
• a rougher flotation stage;
• a rougher low-grade concentrate re-grind stage;
• a low-grade cleaner stage;
• a low-grade re-cleaner flotation stage to produce a zinc concentrate;
• a rougher high-grade concentrate cleaner circuit producing a zinc concentrate;
• the high-grade cleaner tails would be sent to the low-grade re-cleaner flotation stage.
A schematic production flowsheet is shown in Figure 10.
Figure 10: Schematic Production Flowsheet.
Processing Plant Production
Process plant recoveries would range between 80% to 88% for both zinc and copper. Production would be
approximately 145 ktpa of zinc concentrates at a grade of 48% to 52% zinc and 94ktpa of copper
concentrates at a grade of 22% to 26% copper, Table 8.
Parameters Units Totals Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10
Total stoping tonnage kt 20,294 725 2,070 2,115 2,160 2,160 2,170 2,275 2,280 2,280 2,059
LHSF kt 13,191 471 1,346 1,375 1,404 1,404 1,411 1,479 1,482 1,482 1,338
Drift-and-Fill kt 7,103 254 725 740 756 756 760 796 798 798 721
On-reef development kt 1,814 147 307 285 240 240 230 125 120 120
Total ROM tonnage kt 22,108 872 2,377 2,400 2,400 2,400 2,400 2,400 2,400 2,400 2,059
Waste Development kt 2,477 216 347 400 397 308 263 243 236 68
Plant Feed (ROM) Grade
Copper % 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1%
Zinc % 3.7% 3.5% 3.5% 3.6% 3.5% 3.5% 3.5% 3.5% 4.0% 4.0% 4.0%
Plant Recovery Factor (PRF)
Copper % 85% 84% 85% 85% 85% 85% 85% 85% 85% 85% 85%
Zinc % 85% 84% 85% 85% 85% 85% 85% 85% 85% 85% 85%
Concentrates Produced
Copper kt 858 29 93 94 94 94 94 94 93 93 80
Zinc kt 1,372 43 141 145 145 145 145 144 162 163 140
Total kt 2,230 72 234 239 239 239 239 238 255 256 220
Metal Produced - in concentrates
Copper kt 206 7 22 23 23 23 23 23 22 22 19
Zinc kt 686 22 71 72 72 72 72 72 81 82 70
Total kt 892 28 93 95 95 95 95 94 103 104 89
Table 8: Conceptual Project Production Schedule.
There is a low level of geological confidence associated with Inferred Mineral Resources and there is no certainty that further exploration work
will result in the determination of Indicated Mineral Resources or that the Production Target referred to herein will be realised.
Net Smelter Return and Concentrate Sales
The base payabilities for zinc and copper have been assumed at 84.0% and 95.8% respectively. This is
the percentage of metal paid for by smelter customers before any deductions are made based on
concentrate grade supplied. A combined factor has been used to account for TC/RCs, by-product
credits and contingency for other deductibles. These factors are estimated at -9.7% of the metal price
for zinc and -2.1% of the copper price for copper. Based on concentrate grades of 50% for zinc and
24% for copper, the NSR is approximately 74.3% for zinc and 93.7% for copper, Table 9. Gold and silver
credits are expected in the copper concentrates.
NSR Estimate units Zinc Copper
Concentrate grade % 50.0% 24.0%
Smelter payability % metal price 84.0% 95.8%
Table 9: Metal Payabilities.
Transport charges have been estimated at approximately USD 120 per tonne of concentrate, which
includes trucking and rail from the Project site to port and shipping to a final smelter destination. The
transport costs are excluded from the NSR and are accounted for in off-site costs.
Tailings Storage Facility (TSF)
The existing TSF would be left untouched and a new TSF would be constructed in compliance with the
South African Code of Practice for Mine Residue Deposits (SANS 10286). Three possible sites were
investigated. The design of the TSF was carried out by Knight Piésold Consulting. The new TSF is designed
to cater for Phase 1, with a capacity to accommodate 15.5 million tonnes. The storage capacity has
been designed after allowing for 40% of the tailings to be returned underground as paste back-fill over
the duration of Phase 1 operations. The outside slopes of the TSF would be at 1:4 with a 1.6m high starter
wall and the footprint area would be covered with a 1.5mm thick, high-density polyethylene liner.
Page 18 of 41
General Surface Infrastructure
Surface Layout of the Project
The overall conceptual site layout, showing general infrastructure, offices and Project site services for the
Scoping Study mining scenario is shown in Figure 11.
Figure 11: Conceptual Surface Layout of the Project Site.
Transportation Infrastructure
A tarred road, the R357 regional highway, runs from the town of Prieska, 60km away, to the Project site.
Tarred roads link Prieska with the city of Kimberley (240km away) to the north-east and the town of
Upington (260km away) to the north. Existing road intersections on the Project site would be upgraded
to cater for the additional traffic anticipated during the construction and operational phase of the
Project. A new road access to the Project site would be constructed from the existing sealed road that
provides access to Copperton and the Project site.
Regional airports are situated at both Upington and Kimberley with daily flights to Cape Town and
Johannesburg. A 1.7km-long gravel airstrip is located 5km north of the Project area. This airstrip is
operated and maintained by Alkantpan and Orion has perpetual usage rights.
Power Supply and Reticulation
National grid power is available at the Cuprum Substation located adjacent to the Project site and
owned by Eskom, the State utility company. Eskom has confirmed the availability of the 33MW of power
required for the Project. A feasibility level costing exercise indicates that establishing a connection to
the substation will cost AUD 0.5 million for the Eskom infrastructure.
Power supply would also be supplemented by supply from a dedicated 33MW renewable energy
source, (likely a photo voltaic (PV) solar farm or wind energy farm), adjacent to the Project site, to be
built and operated by an independent power producer. Significant cost savings (in the order of 20%)
are anticipated from the grid power costs assumed for the Study of AUD 0.10 per kwhr. PV
supplemented power costs are in the order of AUD 0.08 per kwhr.
Water Supply and Reticulation
Bulk water supply for the Project would be pumped from the Orange River 60km away via the Prieska
Water Works and existing 450 mm diameter steel pipeline. The planned water consumption for the
Project and all other water users supplied by the same pipeline is estimated at 6.2 million litres per day.
To supply this volume of water, a number of upgrades and replacements would be carried out at both
the Prieska Water Works and on the pipeline. The total cost of this upgrade is estimated to be
approximately AUD 1.8 million and is included in the Project capital construction budget.
Other water management infrastructure to be constructed would include:
• a 1 million m3 dewatering dam, to be used for the forced evaporation during mine de-watering;
• a 5,000m3 process water dam, to service the treatment plant; and
• a 163,000m3 pollution control dam.
Buildings, Facilities and Explosives Storage
New buildings and surface facilities would consist of the following amenities:
• a management office block for approximately 60 people (this includes general management,
mining management, treatment plant management and engineering management);
• one change-house facility and adjoining lamp-room;
• a mine rescue room;
• an induction and first aid room, and training centre;
• a central control room housing the supervisory control and data acquisition (SCADA) systems for
the processing plant and for underground engineering;
• an engineering work-shop for surface engineering vehicles with an adjacent paint and oil store;
• a bunded diesel storage area;
• security and access control buildings at the two planned entrances to the Project site; and
• a mine village in Copperton or Prieska to accommodate the commuting workforce.
All offices and accommodation would be portable and containerised where possible.
There are eight serviceable explosive storage magazines and three accessories magazines on site.
These would be used for the planned operations.
Communications and Control Systems
The Project area is currently served by South Africa’s two largest telecom operators, which provide
mobile phone and data coverage via a 60m-high communications tower at the Project site. It is
expected that these services will remain in place over the foreseeable future.
A dustproof, air-conditioned surface control room would be built housing the SCADA system and a
centralised programmable logic control (PLC) system using an Industrial Ethernet 1 Gbit/s fibre optic
network. The SCADA would control and monitor the processing plant and underground rock handling,
pumping and ventilation functions. The SCADA system would also interface with MCCs across the site
for power monitoring via the plant engineering module.
Digital connectivity infrastructure to prepare the mine for future digitalisation would be considered.
Human Resources
A workforce of approximately 850 people would operate the mine as an owner-mined venture.
Continuous roster work schedules are planned, with personnel housed in a commuters’ work village
located in Prieska. Some project construction and shutdown maintenance crews will be housed in
Copperton, closer to the Project site on an ad-hoc basis.
Marketing and Transportation Logistics
Concentrates would be transported from the Project site in covered side tipper trucks or in sealed
shipping containers to either Groveput, Prieska or Kimberley railheads. The concentrates would then
either be loaded into shipping containers at a dedicated loading facility managed by the transport
contractor or the shipping containers arriving from site would be loaded on rail cars. The shipping
containers would be railed to the Coega Port near Port Elizabeth as the primary exporting port facility.
The ports of Cape Town, Port Elizabeth and Saldanha are considered as secondary options.
Operating Costs
Underground Unit Mining Costs
Underground mining costs including labour for Phase 1 were estimated at approximately AUD 48/t
based on numbers derived using a combination of zero-based build-up and benchmarking against
similar activities in other projects. The unit costs as applied for the various proposed mining activities are
shown in Table 10.
Description AUD/t ROM
Labour 8.84
Fuel 1.40
Electricity 0.40
Water 0.28
Plant and equipment 16.70
Ventilation 0.52
Consumables 3.32
Stores and materials 4.71
Explosives 1.81
Backfill 9.71
Total Cost (±20%) 47.69
Table 10: Underground Mining Operating Costs.
Processing Unit Operating Costs
Processing operating costs of AUD 15/t were compiled by DRA from a combination of zero-based
costing and benchmarking of similar operations. The cost build-up is shown in Table 11.
Description AUD/t ROM
Labour 3.47
Fuel 0.15
Electricity 4.50
Crushing and milling 2.51
Flotation reagents 2.99
Water 0.50
Maintenance 0.83
Laboratory 0.05
TSF operations 0.20
Total Cost (±20%) 15.20
Table 11: Processing Operating Costs.
Other Operating Costs
Cost items making up general and administration are:
• management, general and engineering staff not directly related to mining or processing and
including specialist consultants and external service providers, safety and health.
Cost items making up off-mine costs are:
• head office, social and labour commitments, environmental, insurance and marketing costs.
Marketing costs are a fixed amount of AUD 1.25 million based on preliminary discussions with a
concentrate logistics management company.
Total Operating Costs
A summary of the total operating cost structure for the Project is shown in Table 12. All-in-sustaining costs
were estimated at approximately AUD 100/t.
AISC - Operating costs AUD/t ROM
Mining - Underground 47.69
Processing 15.20
General and administration 2.77
Concentrate transport 17.01
Off-mine costs 2.72
Royalty (Government) 9.77
Marketing costs 0.54
Sustaining CAPEX 3.19
Total Operating Cost (±20%) 98.89
Table 12: Total Operating Costs.
Over the Phase 1 duration, the all-in sustaining cost (AISC) per tonne of zinc metal sold is estimated at
approximately USD 1,215/t (USD 0.55/lb) or in terms of equivalent copper sold, approximately USD 3,535t
(USD 1.60/lb).
Capital Cost Estimate and Construction Schedule
Whilst the anticipated total capital cost of construction is approximately AUD 360m to AUD 390m which
includes a 20% contingency, peak funding required is about AUD 300m to AUD 330m. The construction
period, to first mining underground, is estimated to be about 24 months, Figure 12.
Detailed engineering design would be the first workstream to begin once the project is approved and
would run for three months. Thereafter, on-site activities would commence in month 4 and continue until
month 28. The major Project milestones are Shaft dewatering complete – month 23; Access to upper
levels gained in – month 24; Shaft refurbishment and winder commissioning – month 28; Processing plant
commissioning –28; and Mining from below 957 starts – month 32.
Figure 12: Conceptual Project Construction Schedule.
Page 24 of 41
Table 13 outlines a summary of the capital expenditure estimated over the construction period.
Contingency has been estimated at 20% of the underlying capital cost items.
Capital Area Year 1 Year 2 Year 3 Year 4 Total in AUD m
1. Shaft de-watering 13.8 9.2 23.0
2. Shaft winders 12.9 14.6 27.5
3. Shaft refurbishment 3.6 3.6 1.8 9.0
4. Underground establishment 15.8 36.9 52.7
5. Underground mining fleet 16.0 24.0 40.0
6. Surface infrastructure 11.9 12.6 8.9 33.3
7. Process plant 72.2 18.0 90.2
8. Tailings facility 8.4 2.8 11.2
9. EPCM 3.4 10.9 5.5 19.8
10. Owner's costs 2.3 2.3 2.3 7.0
11. Contingency 9.6 29.9 18.4 4.8 62.7
Total (± 35%) 57.5 179.5 110.7 28.8 376.4
Table 13: Estimated Capital Budget Summary (AUD).
Financial Evaluation
Metal Price Forecasts
The following metal prices were used as the base case assumption, informed, for the base metals, by a
view of the Afriforesight long-term forecasts for zinc and copper as of August 2018, Table 14.
Metal Prices USD/lb USD/tonne Source
Copper 3.00 6,614 Afriforesight
Zinc 1.30 2,866 Afriforesight
Precious Metals USD/oz USD/g Source
Gold 1,350 41.99 Orion
Silver 17 0.53 Orion
Table 14: Metal Price Assumptions applied in Scoping Study.
Foreign Currency Exchange Rates
Table 15 lists the foreign currency exchange rates assumed. Exchange rates and ZAR-based commodity
prices are in constant money terms.
FX Rate USD AUD ZAR
USD 1.00 1.40 14.00
Table 15: Foreign currency exchange rate assumptions.
Taxes
A flat corporate tax rate of 28% was assumed, the current applicable corporate tax rate in South Africa.
CAPEX was assumed to be expensed 100% in the year in which it has been spent for tax purposes.
Discount Rates
A discount rate of 12.5% was applied in the base case scenario on constant money terms.
Page 25 of 41
Cash Flow
Phase 1 would be expected to generate about AUD 1.3bn (ZAR 12.7bn) in free cash pre-tax, AUD 930m
post-Tax, Table 16 and Figure 13. Zinc contributes about 52% of the net revenue (after allowing for
concentrate logistics, treatment costs and refining charges).
Phase 1 Capex Capex Year Year Year Year Year Year Year Year Year Year
Parameter Unit
Totals Yr1 Yr2 1 2 3 4 5 6 7 8 9 10
ROM Tonnage kt 22,108 0 0 872 2,377 2,400 2,400 2,400 2,400 2,400 2,400 2,400 2,059
Concentrates Sold - Zn kt 1,372 0 0 43 141 145 145 145 145 144 162 163 140
Concentrates Sold - Cu kt 858 0 0 29 93 94 94 94 94 94 93 93 80
Metal Contained - Zn kt 686 0 0 22 71 72 72 72 72 72 81 82 70
Metal Contained - Cu kt 206 0 0 7 22 23 23 23 23 23 22 22 19
Revenue (Post-NSR) AUD m 3,833 0 0 124 405 412 412 412 411 410 435 437 375
Selling & Realisation AUD m -376 0 0 -12 -40 -40 -40 -40 -40 -40 -43 -43 -37
Net Revenue AUD m 3,457 0 0 112 365 372 371 371 371 370 392 394 338
Mining Cost AUD m -1,054 0 0 -51 -112 -113 -113 -113 -113 -113 -113 -113 -100
Processing Cost AUD m -336 0 0 -17 -36 -36 -36 -36 -36 -36 -36 -36 -32
General & Admin. AUD m -61 0 0 -6 -6 -6 -6 -6 -6 -6 -6 -6 -6
Off-mine Costs AUD m -72 0 0 -6 -7 -7 -7 -7 -7 -7 -7 -7 -7
Royalties (Govt.) AUD m -216 0 0 -1 -2 -13 -29 -26 -29 -29 -30 -31 -26
Cash Operating Costs AUD m -1,740 0 0 -81 -163 -176 -191 -189 -191 -191 -193 -193 -172
Cash Operating Profit AUD m 1,717 0 0 31 202 196 180 182 180 179 199 201 167
Project Capital AUD m -376 -57 -180 -111 -29 0 0 0 0 0 0 0 0
Sustaining Capital AUD m -71 0 0 -5 -5 -5 -5 -30 -5 -5 -5 -5 -5
Net Cash flow pre-Tax AUD m 1,270 -57 -180 -84 169 192 176 152 175 174 195 197 162
Income Tax AUD m -343 0 0 0 0 0 -47 -43 -49 -49 -55 -55 -45
Net Cash flow after Tax AUD m 928 -57 -180 -84 169 192 128 110 126 126 140 141 117
Table 16: Prieska Project Phase 1 Conceptual Cash Flow Summary.
There is a low level of geological confidence associated with Inferred Mineral Resources and there is no
certainty that further exploration work will result in the determination of Indicated Mineral Resources or
that the Production Target or financial forecast information referred to in this release will be realised.
Figure 13: Profile of the Prieska Project Phase 1 Conceptual Cash Flow Post-Tax. The right axis shows the Cumulative Cashflow; the left
axis shows the Annual Net Cash Flow.
Financial Forecast Evaluation
The main production and financial metrics are shown in Table 17. In keeping with the low level technical
and economic assessment criteria for a Scoping Study, the estimated amounts are considered
approximations and key assumptions are provided within the report.
Estimated Estimated
Price and FX Assumptions Unit Financial Performance Unit
Value Value
Metal price – Cu (USD 3.00/lb) USD/t 6,6148 NPV (pre-tax) @12.5% discount rate AUD m 400 - 440
Metal price – Zn (USD1.30/lb) USD/t 2,8668 IRR (pre-tax) % 38%
Exchange rate ZAR:USD 14 : 1 Payback from first production years 3
Exchange rate ZAR:AUD 10 : 1 Undiscounted free cash flow (pre-tax) AUD bn 1.2 – 1.3
Exchange rate AUD:USD 1.4 : 1 Peak funding AUD m 300 – 330
Estimated Estimated
Production Metrics Unit Project Cost Metrics Unit
Value Value
Life of Mine (Phase 1) years 10 Average cash operating unit cost (C1) AUD/t 83
Treatment plant capacity ktpa 2,400 All-in-sustaining cost per unit ROM t AUD/t 100
Phase 1 tonnage - ROM mt 22 All-in-sustaining cost per unit Zn eq t sold AUD/t Zn 1,701
Phase 1 tonnage - processed mt 22 All-in-sustaining cost per unit Cu eq t sold AUD/t Cu 4,949
Concentrate tonnage - Zn mt 1.4 Price received (net of NSR) - Zn AUD/t Zn 2,982
Concentrate tonnage - Cu mt 0.9 Price received (net of NSR) - Cu AUD/t Cu 8,677
Concentrate grade - Zn % 50.0% All-in-sustaining margin % 43%
Concentrate grade - Cu % 24.0% Operating breakeven grade (Zn eq) % 4.1%
NSR as % of metal price - Zn % 74.3%
8Guided by Afriforesight (Pty) Ltd long-term consensus forecast as of August 2018, converting to a copper price of USD 6,614/tonne and a zinc price
of USD 2,866/tonne.
Estimated
NSR as % of metal price - Cu % 93.7% Project Cash Flows Unit
Value
Metal sold (in concentrates) - Zn kt 686 LoM net revenue AUD m 3,457
Metal sold (in concentrates) - Cu kt 206 LoM operating costs AUD m 1,740
Total sales as Zn equivalent kt 1,285 Project start-up capital expenditure AUD m 360 - 390
Total sales as Cu equivalent kt 442 Sustaining capital expenditure AUD m 65 - 75
Table 17: Key Scoping Study Results for Phase 1 of the Prieska Zinc Copper Project. Note that the overall Study accuracy is level ± 35%.
There is a low level of geological confidence associated with Inferred Mineral Resources and there is no
certainty that further exploration work will result in the determination of Indicated Mineral Resources or
that the Production Target or financial forecast information referred in this release will be realised.
Sensitivity
The Phase 1 NPV estimate is most sensitive to the ZAR-USD exchange rate variations, followed by zinc
price and copper price changes. The NPV is also more sensitive to operating costs than capital
expenditure. Pre-tax NPV ranges from AUD 250m to AUD 550m as the ZAR-USD exchange rate varies
from -15% to +15% of the base case assumptions, Figure 14.
Figure 14: Sensitivity Analysis Chart.
Funding
Orion is listed on the Australian Securities Exchange (ASX: ORN) and it has a secondary listing on the
Johannesburg Stock Exchange (JSE: ORN). Orion currently intends to fund the development of the
Project by means of a combination of debt and equity.
Project Closure Provisioning
In compliance with South Africa legislation and guided by international best practice guidelines,
financial provision for mine rehabilitation and closure has been made for an amount of AUD 18m (ZAR
180m).
Future Activities
A BFS is in progress and due for completion in Q2 2019. Based on a positive project outcome and
assuming funding is available, construction could begin in the second half of 2019. Underground mining
would then begin 24 months thereafter, with the plant being commissioned from Month 28. Open-pit
mining of shallow targets is being considered as a potential opportunity once Phase 1 is under way and
is the subject of a separate feasibility study.
Errol Smart
Managing Director and CEO
19 December 2018
ENQUIRIES
Investors Media JSE Sponsor
Errol Smart – Managing Nicholas Read Barnaby Hayward Rick Irving
Director & CEO
Denis Waddell – Chairman Read Corporate, Australia Tavistock, UK Merchantec Capital
T: +61 (0) 3 8080 7170 T: +61 (0) 419 929 046 T: +44 (0) 787 955 1355 T: +27 (0) 11 325 6363
E: info@orionminerals.com.au E: nicholas@readcorporate.com.au E: orion@tavistock.co.uk E: rick@merchantec.co.za
Suite 617, 530 Little Collins Street
Melbourne, VIC, 3000
Competent Person’s Statements
The information in the ASX release of 18 December 2018 that relates to the Production Targets is based on mining-
related information incorporated under the supervision of Mr Walter Shamu, a Competent Person who is a member
of the Australasian Institute of Mining and Metallurgy. Mr Shamu takes overall responsibility for the release as
Competent Person. Mr Shamu is an employee of Orion. Mr Shamu has sufficient experience that is relevant to the
type of mining and type of deposit under consideration and to the activities being undertaken to qualify as a
Competent Person as defined in the 2012 Edition of the JORC Code. Mr Shamu consents to the inclusion in this
release of the matters based on his information in the form and context in which it appears.
The information in the ASX release of 18 December 2018 that relates to the Production Targets is based on mining
information independently reviewed by Mr. John Edwards, Fellow of South African Institute of Mining and Metallurgy,
(a Recognised Overseas Professional Organisation, (ROPO), a Competent Person. Mr. Edwards is a consultant to
Orion. Mr. Edwards has sufficient experience that is relevant to the type of mineral processing 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 Edwards consents to the inclusion in this release 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).
Section 4 Estimation and Reporting of Ore Reserves modified for a Scoping Study which includes an approximate Production Target and/or Forecast
Financial Information (as advised in the ASX Scoping Study Interim Guidelines). No JORC (2012) Ore Reserves are being reported.
(Criteria listed in Section 1, and where relevant in Section 2, also apply to this section.)
Criteria JORC Code explanation Commentary
Mineral Resource • Description of the Mineral Resource estimate used as a • No JORC (2012) Ore Reserve estimate is classified and reported.
estimate for conversion to basis for the conversion to an Ore Reserve. • The preliminary production target is based on the total underground Mineral Resources for the Prieska
Ore Reserves • Clear statement as to whether the Mineral Resources are Project of 28.73 Mt 3.77% Zn and 1.16% Cu, classified and reported in terms of JORC 20129 in ASX
reported additional to, or inclusive of, the Ore Reserves. release 18 December 2018. The modifying factors, preliminary designs and schedules were done using
then Mineral Resources classified and released in February (refer ASX release 8 February 2018) and
April (refer ASX release 9 April 2018; with the December Mineral Resource (refer ASX release 18
December 2018) retrofitted.
• The Mineral Resources are based on drilling data available as at 30 November 2018.
• The Competent Person for the Mineral Resource is Mr Sean Duggan of Z* Consultants, RSA.
Site visits • Comment on any site visits undertaken by the • No JORC (2012) Ore Reserve estimate is classified and reported.
Competent Person and the outcome of those visits.
• If no site visits have been undertaken indicate why this is
the case.
Study status • The type and level of study to enable Mineral Resources • Feasibility studies are in progress but have not been completed; accordingly, an Ore Reserve is not
to be converted to Ore Reserves. being classified and reported.
• The Code requires that a study to at least Pre-Feasibility • A Scoping Study Technical Report has been completed at a low level of confidence relative to a BFS.
Study level has been undertaken to convert Mineral • The Scoping Study has been prepared to an accuracy level of ± 35% using Indicated and Inferred
Resources to Ore Reserves. Such studies will have been Mineral Resources; appropriate mine planning and modifying factors have been applied
carried out and will have determined a mine plan that is commensurate to a Scoping Study level of accuracy and are deemed to have reasonable prospects
technically achievable and economically viable, and of being technically achievable and economically viable.
that the material Modifying Factors have been • Section 4 of JORC Table 1 is being completed as part of the Scoping Study requirement to disclose
considered. material modifying factors and assumptions underpinning a conceptual Production Target estimates
are linked to forecast financial Information.
Cut-off parameters • The basis of the cut-off grade(s) or quality parameters • The cut-off grade of 4,1% Zn equivalent was estimated based on appropriate metal prices,
applied. anticipated plant recovery factors, metal payability factors, mining dilution and cost inputs.
• The cut-off grade table and Zn equivalent grade estimation is found in the body of the release.
• The payability factors stated in the above estimates assume recovery of silver (Ag) and gold (Au) from
the two concentrate streams. It is estimated from metallurgical testwork that the Cu concentrate will
produce 50 to 60g/tonne Ag and 2 to 3 g/tonne of Au while the Zn concentrate will produce 15 to 20
g/tonne Ag and 1 to 2 g/tonne of Au. Due to the anticipated smelter payment terms for the Zn
concentrate, no revenue would be received for the Ag produced.
Mining factors or • The method and assumptions used as reported in the • No JORC (2012) Ore Reserve estimate is classified and reported.
assumptions Pre-Feasibility or Feasibility Study to convert the Mineral • The Scoping Study used the preliminary design to determine an indication of the viability of the
Resource to an Ore Reserve (i.e. either by application of proposed mining project using Datamine© Mining Software and a Mine Shape Optimiser (MSO) as
appropriate factors by optimisation or by preliminary or detailed in the body of the ASX release. Deductions were made for material excluded by the MSO,
9
Mineral Resource reported in ASX release of 18 December 2018: “Landmark Resource Upgrade Sets Strong Foundation for Development of Prieska Zinc-Copper Project” available to the public on
www.orionminerals.com.au/investors/market-news. Competent Person Orion’s exploration: Mr. Pottie Potgieter. Competent Person: Orion’s Mineral Resource: Mr. Sean Duggan. Orion is not aware of any new
information or data that materially affects the information included above. For the Mineral Resource, the company confirms that all material assumptions and technical parameters underpinning the estimates in
the ASX release of 18 December 2018 continue to apply and have not materially changed. Orion confirms that the form and context in which the Competent Person’s findings are presented here have not
materially changed.
31
Criteria JORC Code explanation Commentary
detailed design). geological and pillars losses and a mining extraction factor. Dilution is included during the MSO
• The choice, nature and appropriateness of the selected process. The Mineral Resource conversion factors are listed below:
mining method(s) and other mining parameters including
associated design issues such as pre-strip, access, etc. Mineral Resources Conversion Factors for Production Scheduling
• The assumptions made regarding geotechnical Parameter Source Tonnage
Zn equivalent metal
parameters (e.g. pit slopes, stope sizes, etc.), grade contained
control and pre-production drilling. Mineral Resources (below Cut-off: 4.5% Zn Eq.) Estimated 12% 8%
• The major assumptions made, and Mineral Resource
Mine Design Losses MSO 10% 11%
model used for pit and stope optimisation (if
appropriate). Design stope dilution MSO 10% n/a
• The mining dilution factors used.
Geological/pillar Losses Assumed 5% 5%
• The mining recovery factors used.
• Any minimum mining widths used. Mining extraction factor (Mining recovery factor) Assumed 95% 95%
• The way Inferred Mineral Resources are utilised in mining
studies and the sensitivity of the outcome to their
inclusion. • The above factors result in a 78% conversion of Mineral Resource tonnes to tonnes used in the
• The infrastructure requirements of the selected mining production scheduling and a 75% Resource conversion to Zn equivalent metal in the production
methods. schedule.
• The modifying factors, preliminary designs and schedules were done using then Mineral Resources
classified and released in February (refer ASX release 8 February 2018) and April (refer ASX release 9
April 2018) and the same factors were then applied to the December Mineral Resource (refer ASX
release 18 December 2018).
• Material assumptions regarding timeframe for development and production: It is assumed that the
BFS is positive, water may be realistically and economically pumped from underground and that the
Mining Right is granted by the authorities.
• The conceptual mine model scenario for the Scoping Study can be summarised as the establishment
of underground operations to extract the extensions of the Indicated and Inferred Mineral Resource
from the hypogene Deep Sulphides (the Deeps) at > 1,000m accessed via existing underground
mine infrastructure which would require dewatering and some refurbishment. Preliminary
observational and non-destructive testing studies by specialists on exposed underground
infrastructure as well as water tests suggest a 15% replacement would probably be required (refer
ASX release 2 February 2018). During historical operations, water was not required to be pumped
from the mine. The current water-level is at 330m and it is assumed that successful dewatering of the
operation will then reveal the actual conditions for mining at >1,000m. This factor has been built into
the conceptual mine schedule and anticipated estimated costs. Gas hazards, equipment, backfill
design, crushing and hoisting, mine ventilation and underground rehabilitation of existing structures
also formed part of these mining studies.
• Mining Method: Historically a tabular body of mineralisation was almost continuously economically
mined over a strike length of 2,400m, between 1971 and 1991, from levels -100m to approximately -
850m using the LHOS mining method. Assuming successful dewatering, refurbishment and new mine
infrastructure are realised, preliminary mining scenarios propose Drift-and-fill (an estimated 75% of
monthly production) for the flatter dipping sections in areas and Long-hole-open-stoping-with-fill
(LHSF) (an estimated 25% of monthly production) for the steeper sections - based on the shape and
layout of the Mineral Resource. Blasted rock from both operations is loaded into trucks and trammed
back the existing crusher station at 920 Level.
• Geotechnical: Observations from the existing tunnels in the upper levels of the historic mine indicate
very competent rock with very little tunnel-support. Localised roof bolting was carried out in fractured
sections. Geotechnical studies were carried out by the Company. 30 compressive and tensile strength
tests were carried out on the hanging wall, mineralised zone and footwall rocks from 8 drill holes to
32
Criteria JORC Code explanation Commentary
estimate rock mass ratings at depth. The results indicate competent rock for all three rock-types.
• Mining Dilution Factors: 10%
• Mining Recovery Factors: 95%
• Minimum Mining Widths: Drift-and-Fill: 4m by 4m high stope dimensions with access drives of 4.5m by
4.5m (estimated at approximately 70,000 tonnes/month). LHSF: 5-20m with a strike span of 60m giving
approximate stope capacities ranging between 26,000 tonnes and 52,000 per stope (estimated at
approximately 130,000 tonnes/month). Planning assumed at least two operating stopes at a time.
Inter-level spacing is designed at 20m. Tunnel dimensions designed at 5 by 6m for main ramps and
footwall tunnels and 4m-4.5m by 4m-4.5m for stope access drives.
• Mineral Resource Model: It is important to note that the Inferred Mineral Resource lies at the base of a
tabular mineralised body which was previously successfully mined. In the Scoping Study mining
scenario, Indicated and Inferred are interspersed in the Mineral Resource model (refer ASX release 18
December 2018) mainly defined by drill spacing constraints and the mine modelling follows suit.
• Inferred Mineral Resources are only scheduled in the latter years of the production forecast, beyond
the payback period.
• Infrastructure Requirements for the chosen mining methods:
o Existing Infrastructure (remaining from previous mine operation): The project area is well serviced
by infrastructure that was originally established for the historical mine; this includes the old mine
roads on the site itself, some accommodation, telecommunications, water and electricity
provision which are in use. On surface there remain the Hutchings Shaft, the main portal and
decline which is operational. Underground, the mine tunnels and stopes are mainly accessible
to 330m. It is assumed that the old mine infrastructure below water level at 330m such as the
existing underground workshop at 957 Level, the crushing and shaft loading arrangement at 920
Level and the pre-existing mine ventilation facilities (Boehmka and Beecroft Shafts (note the
surface structure and fans have been removed and the shaft collars made safe) would be
refurbished or rebuilt. Preliminary mining studies on these aspects have been included in the
Scoping Study process and to inform the BFS studies underway.
o Additional Infrastructural Requirements for the chosen mining methods: the following were
considered as part of the Scoping Study. The refurbishment or rebuilding of existing mine
infrastructure including a Koepe Man-and-Winder for the Hutchings Shaft and new or second-
hand equipment for the remaining shafts; additional water and electrical provisions from
existing structures; deepening of the ventilation shafts and additional ventilation airways
constructed; additional power reticulation; the additional availability of power from
neighbouring renewable solar and wind plants presently in the process of construction; water
dams (including effluent dams, potable water facilities, sewerage treatment plant, process
water and storm water management) are considered at a high-level. New buildings and
facilities: management and office block, underground change and ablution facility, mine
rescue room, training centre, central control room for the mine and processing plant;
engineering workshop; a bunded diesel storage area; security and access control for mine
safety.
Metallurgical factors or • The metallurgical process proposed and the The design of the processing plant allows for the Phase 1 treatment of the hypogene (underground) feed
assumptions appropriateness of that process to the style of and the optional, later stage, supergene (open-pit) with modifications. Unit processing costs and plant
mineralisation. design and equipment assumes underground feed only in Phase 1. Only Phase 1 is addressed in the
• Whether the metallurgical process is well-tested Scoping Study.
technology or novel in nature.
• The nature, amount and representativeness of • Metallurgical Process: conventional, crushing, grinding and differential froth flotation processing is
metallurgical test work undertaken, the nature of the proposed for the hypogene material which should produce saleable concentrates of Zn and Cu with
metallurgical domaining applied and the corresponding the potential for Ag and Au as by-products.
metallurgical recovery factors applied. • Appropriateness: appropriate for the type of material anticipated from the mining operation.
• Tested Technology: Not only is the technology in common use in the industry but it was successfully
33
Criteria JORC Code explanation Commentary
• Any assumptions or allowances made for deleterious used during the previous operation of the Prieska Mine. Over the 20-year mine life, metal recoveries
elements. averaged 85% for both zinc and copper into concentrate grades ranging between 28% to 30% for
• The existence of any bulk sample or pilot scale test work copper (in the copper concentrates) and 51% to 53% for zinc (in the zinc concentrates) (refer ASX
and the degree to which such samples are considered release 15 November 2017).
representative of the orebody as a whole. • Metallurgical Testwork: Specialists: Mintek Laboratories under the guidance of the DRA Metallurgical
• For minerals that are defined by a specification, has the team undertook the metallurgical testing. Open and closed circuit testwork on the copper-circuit and
ore reserve estimation been based on the appropriate zinc-circuit. Process flow tests to determine the optimal recovery processes based on the metallurgical
mineralogy to meet the specifications? characteristics of the material. 800kg of test sample was used from 7 drill holes ensuring representivity
from various zones of the deposit (the NE and SW zones). Using geological logging and assay values
for the drill holes, the sample would be split further into a zinc-dominant and copper-dominant
material each of which were tested independently. These hypogene zones contain, in decreasing
order of abundance, pyrite, sphalerite, chalcopyrite, pyrrhotite, and minor amounts of galena.
Accessory minerals include magnetite, molybdenite, marcasite, arsenopyrite, minor gold and silver.
Testwork achieved higher-than-anticipated recoveries. Flow-sheet development was carried out on
blended samples.
• Recovery Factors: Testwork indicates metallurgical recovery rates of approximately 80-88%, resulting in
higher zinc and copper concentrates of 48-52% and 22 to 26%, respectively.
• Assumptions or allowances made for deleterious elements: historic sales of the PCM concentrates
were recorded as clean with low concentrations of penalty elements. 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.
• Bulk sample testwork and representivity: discussed under “testwork” above.
• With respect to minerals that are defined by a specification and used in the Production Target
estimate, the metallurgical testwork was done to produce saleable products.
• Metallurgical testing is still in ongoing. Results are reported in the Scoping Study to 22 October 2018.
Metallurgical results were released to the ASX on 17 November 2017, 8 February 2018, 1 March 2018,
12 June 2018 and 22 October 2018.
Environmental • The status of studies of potential environmental impacts • The previous mine owner, PCML, obtained a Conditional Closure Certificate in 1996 from the
of the mining and processing operation. Details of waste authorities in terms of the Minerals Act, 1991, in terms of which rehabilitation of the old mine is legally
rock characterisation and the consideration of potential considered complete; with the condition that a fund, be provided to rehabilitate any residual or
sites, status of design options considered and, where deleterious aspects related to the closure of the mine and the remaining old Tailings Storage Facility
applicable, the status of approvals for process residue (TSF) which potentially may occur in the future. The Nature Conservation Trust No. 723/89 Fund
storage and waste dumps should be reported. currently stands at ZAR20,550,812 (end July 2018 - Financial Year End).
• The existing Repli Prospecting Right has an Approved EMPlan (Environmental Management Plan) and
the Vardocube Prospecting Right has the newer, Environmental Authorisation (EA), which form part of
the prospecting rights and compliance therewith.
• The new Mining Right Application (MRA) of the Repli Prospecting Right area was submitted on 6 April
2018 together with an Environmental Authorisation Application in terms of the NEMAct, 1998, which
runs concurrent to the Mining Right Application. Similarly, the EA application linked to the Vardocube
MRA was submitted to the authorities on 27 September 2018. Specialist studies to inform the
Environmental Impact Reports (EIR), Environmental Impact Assessments (EIA) and EMPrs
(Environmental Management Programme), Integrated Water and Waste Management Plan (IWWMP)
and Water Use Licenses (WUL) for the EA application process are underway. The EA process also
integrates the concerns raised during the Public Participation Process and incorporates mitigation
measures for issues raised by affected parties. Some agreements have already been concluded
including for the solar energy projects located nearby.
• A preliminary estimate for the Financial Provision for the LoM is ZAR 180 million. This total amount is in
34
Criteria JORC Code explanation Commentary
line with specialist recommendations and the EIA;
• In accordance with legislated timelines, the grant decision by the authorities for the Environmental
Authorisations are anticipated by Q1 2019 for the Repli EA and Q3 2019 for the Vardocube EA.
Infrastructure • The existence of appropriate infrastructure; availability of • The combined area for the Repli and Vardocube Prospecting Rights upon which the mine and mine
land for plant development, power, water, transportation infrastructure is planned, is approximately 6,766 hectares in extent.
(particularly for bulk commodities), labour, • Surface Rights: Repli Trading No. 27, an indirect subsidiary of Orion Minerals Ltd, and the entity which
accommodation; or the ease with which the infrastructure holds the Prospecting Right and the Mining Right application, controls the surface use for the farm
can be provided or accessed. Vogelstruis Bult 104 and Slimes Dam 154 (Prieska District, Northern Cape Province) primarily in the form
of direct surface right ownership (97.5% shareholding in PCML (Prieska Copper Mining Limited);
servitude rights written into the property deed for land owned by the Request Trust as well as a long-
term Surface Users Agreement signed in November 2018 between the latter in which users rights for
prospecting and mining operations are guaranteed and the land-owner compensated. In addition,
the holder of a prospecting and mining right is entitled to carry out the relevant operations for the
winning of minerals in terms of Section 54 of the MPRDAct, 2002. To date, Orion is aware of no Land
Claims that have been registered for the properties. The Company has used reasonable endeavours
to confirm that land is therefore available for the building of new or use of any existing infrastructure.
• Infrastructure Requirements:
o Existing Infrastructure (remaining from previous mine operation): This is discussed in the body of
the ASX release.
o It is assumed that the old mine infrastructure below the 330masl water level would be
refurbished or rebuilt. Preliminary mining studies on these aspects have been included in the
Scoping Study process and inform the BFS studies currently underway.
o Additional Infrastructural Requirements: This is discussed in the body of the ASX release.
Costs • The derivation of, or assumptions made, regarding • Conceptual Capital Cost (CAPEX) Assumptions:
projected capital costs in the study. o CAPEX used: AUD 376 million, then a range was reported.
• The methodology used to estimate operating costs. o Conceptual Construction Schedule for the first 28 months.
• Allowances made for the content of deleterious o Initial Life of Mine (LoM) of about 10 years.
elements. The derivation of assumptions made of metal o Contingency of 20% of the underlying capital cost items.
or commodity price(s), for the principal minerals and co- o Target accuracy of ±35%.
products. o The base currency is the South African Rand (ZAR) and an exchange rate has been fixed at ZAR
• The source of exchange rates used in the study. 14 : USD 1 and ZAR 10 : AUD 1.
• Derivation of transport charges. o Estimate is base dated to August 2018.
• The basis for forecasting or source of treatment and • Source of CAPEX estimated costs:
refining charges, penalties for failure to meet o Process Plant: A costed Mechanical Equipment List (MEL) with the remainder of the costs
specification, etc. factorised from the MEL.
• The allowances made for royalties payable, both o Surface Infrastructure: items sized and quantified off preliminary assumptions, designs or
Government and private. previous projects. Costs determined from similar recent projects or databases (often supplied by
consultants) relative to quantified components. Independent pricing obtained as follows: TSF
and Return Water Dam by a specialist consultancy; bulk power supply upgrade from a
specialist consultancy; water supply pipe-line upgrade from a specialist consultant.
o Underground Mining: quotes received for the underground fleet, the evaporators; the winders
(man-winder) costed as new but optimised the configuration, rock-winder costed as second-
hand, ventilation fans by a ventilation consultant. All remaining items were sized or quantified
off preliminary assumptions, designs or previous projects.
o Open-pit Mining: Not included in the financial forecast estimates.
o General: EPCM and consultant costs are factorised off the various capital estimates in each of
the above areas at a percentage as observed across various projects done by consultants,
transport during construction, first fills, consumables and spares are allowances based off
previous projects done by consultants. Project owner’s costs are from Orion Minerals.
35
Criteria JORC Code explanation Commentary
• Conceptual Operating Cost (OPEX) Methodology and Assumptions:
o Operating costs of approximately AUD1.8bn with AISC (all-in-sustaining-costs) of AUD100/t.
o Total Conceptual Operating Cost Summary are provided in the body of the ASX release.
o For the underground feed, 30% re-handling has been allowed for.
o OPEX costs for the scenario were estimated by modified numbers using a combination of zero-
based build-up and benchmarking against similar activities in other projects.
o Underground Mining: AUD 48/t. Mining carried out by contractor services; geotechnical,
geology and grade-control by Orion staff. Unit mining costs supplied by DRA using a
combination of zero-based build up and benchmarking against similar activities in other
projects. Costing includes trackless equipment, mining consumables, services, labour, trucking
and backfill.
o Open-Pit: not included in financial forecast estimations.
o Material Processing: Compiled by reputable contractor from a combination of zero-based
costing and benchmarking of similar operations. Labour rates are current industry norms for an
operation of the same scale. Processing costs for hypogene (underground) material = AUD 15/t.
Costs include labour, fuel, power, crushing & milling, flotation & reagents, water costs,
maintenance, laboratory and TSF operations.
o General and Admin and Off-mine costs are discussed in the body of the ASX release.
o Marketing costs are a fixed amount of AUD1.25 million based on preliminary discussions with a
concentrate logistics management company.
• Exchange Rate: Base currency is ZAR with a fixed exchange rate at ZAR 14 : USD 1 and ZAR 10 : AUD 1.
The rates of exchange used have been empirically estimated and are based on exchange rates at
the time of this report.
• Commodity price assumptions and source: see “revenue below”.
• Derivation of Transport charges: for the purposes of this Study it is assumed that the concentrate will
be trucked from the processing plant at the mine to Kimberley daily. Shipping containers will be
railed to Coega Port near Port Elizabeth. Cape Town or Saldanha Bay are options. Charges
estimated at USD120 per tonne of concentrate.
• Forecasting Treatment & Refining Charges (and penalties): The conceptualised scenario anticipates
that an unrefined product will be sold to the market.
• Penalties and allowances for deleterious elements: refer to the NSR estimate detailed in this release.
• Royalties:
o Government Royalties: the royalties were set at the formula for “unrefined minerals”, in terms of
the Royalties Act, 2010, linked to the MPRDA, 2002. Where Y = 0.5 + [EBIT/(gross sales of
unrefined minerals) x9] x 100 {maximum Y is 7.0%}.
o Private Royalties: No private royalties were included in the estimate.
• The estimates are for the total project and do not take into account the percentage of the
Company’s ownership of the right holding companies (i.e. between 70% and 73.67%).
Revenue factors • The derivation of or assumptions made regarding • Head Grade Assumptions:
revenue factors including head grade, metal or Mining modifying factors were applied to Mineral Resources grades as covered in the report.
commodity price(s), exchange rates, transportation and
treatment charges, penalties, net smelter returns, etc.
• The derivation of assumptions made of metal or
commodity price(s), for the principal metals, minerals
and co-products.
36
Criteria JORC Code explanation Commentary
• Metal Price Assumptions
Metal Prices USD/tonne USD/lb Source
Copper 6,614 3.00 Afriforesight
Zinc 2,866 1.30 Afriforesight
Precious Metals USD/oz Source
Gold 1,350 Orion
Silver 17 Orion
• Contribution by the co-products of silver and gold were included in the estimates for the Phase 1
scenario.
• Foreign Currency Exchange Rate Assumptions:
FX Rate USD AUD ZAR
USD 1.00 1.40 14
The rates of exchange used have been empirically estimated and are based on exchange rates at
the time of this report.
• Assumptions or allowances made for deleterious elements: historic sales of the PCM concentrates
were recorded as clean with low concentrations of penalty elements which were cadmium, iron
(applicable for zinc concentrates only), mercury and bismuth. 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.
• Payabilities: The payabilities for zinc and copper have been assumed at 84.0% and 95.8%
respectively. This is the percentage of metal paid for by smelter customers. A combined factor has
been used to account for TC/RCs, by-product credits and penalty elements. These factors are
estimated at -9.7% of the zinc price for zinc and -2.1% of the copper price for copper. The smelter
payabilities and combined factors have been selected based on the discussions mentioned above.
Based on concentrate grades of 50% for zinc and 24% for copper, the NSR is estimated at
approximately 74.3% and 93.7% respectively.
• The conceptual NSR Estimate table is provided in the body of the ASX release.
• Derivation of Transport charges: Charges assumed at USD120 per tonne of concentrate.
• Derivation of assumptions made for metal for commodity price(s) for the principal metals, minerals
and co-products: Independent estimates for Zn and Cu; guided by Afriforesight (Pty) Ltd long-term
consensus forecast as of August 2018.
Market assessment • The demand, supply and stock situation for the particular • Demand, supply and stock situation for zinc and copper: the global supply and demand balance for
commodity, consumption trends and factors likely to zinc is at a deficit forecasted to be balanced by an increase in smelter production and several new
affect supply and demand into the future. mines; non-the-less it is anticipated that there will be an overall strong demand for zinc concentrates
• A customer and competitor analysis along with the over the coming years. Copper is consistently in demand. The supply of copper is presently in surplus
identification of likely market windows for the product. but reserve depletion in existing mines is anticipated to create an increase in demand after 2020.
• Price and volume forecasts and the basis for these • Customer Analysis: historically the concentrates produced from the PCM were regarded as clean
forecasts. products with few and low-levels of impurities. Current assay results support this and it is concluded
• For industrial minerals the customer specification, testing that the concentrates will be in demand to blend down impurities in other concentrates. Nine zinc
and acceptance requirements prior to a supply smelters and ten copper smelters are listed in the Scoping Study as potential customers.
37
Criteria JORC Code explanation Commentary
contract. • No formal competitor analysis has been included at the Scoping Study stage.
• Metal price and volume forecasts: Metal price assumptions for copper and zinc as supplied by
Afriforesight, August 2018 and consensus forecasts were the guideline used to estimate Study prices.
Economic • The inputs to the economic analysis to produce the net • The inputs for the NPV estimation are tabulated in the body of the ASX release.
present value (NPV) in the study, the source and • Valuation Methodology
confidence of these economic inputs including The Discounted Cash Flow (“DCF”) method of valuation which is commonly used to determine the
estimated inflation, discount rate, etc. attractiveness of an investment opportunity, discounts future free cash flow projections to arrive at an
• NPV ranges and sensitivity to variations in the significant NPV. For the purposes of this Scoping Study, a discount rate commonly used for similar projects of
assumptions and inputs. 12.5% has been used.
In generating the financial model, the following parameters and assumptions were used:
o The financial model is in real terms;
o The model was set up in months for the first three years, and annual increments for the
remainder of the mine life. The financial year ending of the Company is June;
o No escalation has been applied;
o The operation is valued as a single tax entity;
o Royalties were set at the formula applicable for unrefined minerals;
o No salvage value was included for plant and mining equipment remaining at the end of
operations.
o South Africa corporate tax rate of 28% has been applied.
o NPV ranges: AUD 250m to AUD 550m.
o Sensitivity analysis for the economics shows the Project most sensitive to the ZAR-USD exchange-
rate, followed by zinc-price, copper-price and zinc-grade.
550
NPV (AUDm) pre-tax
500
450
400
350
300
250
-15% -10% -5% Base 5% 10% 15%
Zinc Price Copper Price Opex
Capex USD-ZAR Zn Grade
• Using the assumed factors and inputs, Zinc contributes 52% of the LoM revenue post net smelter return
and concentrate logistics costs.
Social • The status of agreements with key stakeholders and • Surface Use: The Company, through Repli Trading No. 25 (Pty) Ltd controls Prieska Copper Mines
matters leading to social licence to operate. Limited which owns some of the surface rights. The Company has a long-term Surface user
Agreement, signed November 2018, with the remaining surface right holder for the area of the
proposed mine infrastructure.
• Social License to operate:
o This aspect is guided by the Mining Charter and regulated by the Social and Labour Plan (SLP)
which was compiled and submitted as part of the Repli and Vardocube Mining Right
Applications. The SLP is currently being evaluated by the South African regulatory authorities.
38
Criteria JORC Code explanation Commentary
o The Company signed an MOU (Memorandum of Understanding) with the Siyathemba
Municipality for the Prieska District in February 2018 in which the Municipality endorsed the SLP.
o Several significant social investment initiatives proposed in the SLP, designed to and agreed
between the Company and the Siyathemba Municipality have already been started including
the provision of internet facilities to the public in Prieska assisting the local community with
application for work and/or as service providers for the proposed mining operation. The
Company views the SLP as being a dynamic document that will continue to be revised as the
Project develops and the needs and understanding of the local community change.
Other • To the extent relevant, the impact of the following on the • Identified material natural occurring risks: nil.
project and/or on the estimation and classification of the • Status of material legal agreements: all agreements are current and active. Detail of the status of the
Ore Reserve legal agreements was not addressed in the Scoping Study Technical Report.
• Any identified material naturally occurring risks. • Status of material marketing agreements: no marketing agreements are in place at the Scoping Study
• The status of material legal agreements and marketing stage.
agreements. • Tenement Status: Mineral tenure in South Africa is regulated by the MPRDA (2002) with the
• The status of governmental agreements and approval environmental aspects regulated by NEMA (1998), both managed under the authority of the DMR.
critical to the viability of the project, such as mineral The Project mineral tenure or tenement holding comprises a set of contiguous prospecting rights
tenement status, and government and statutory surrounding the old PCM area: the Repli-Copperton Prospecting Right (Repli Prospecting Right), the
approvals. There must be reasonable grounds to expect Vardocube Prospecting Right, the Bartotrax Prospecting Right and the Repli-Doonies Pan Prospecting
that all necessary Government approvals will be Right. Applications for mining rights have been submitted to the DMR for both the Repli Prospecting
received within the timeframes anticipated in the pre- Right area and the Vardocube Prospecting Right area.
feasibility of Feasibility study. Highlight and discuss the
materiality of any unresolved matter that is dependent The primary tenement licenses and applications are detailed below:
on a third party on which extraction of the reserve is Repli Prospecting Right:
contingent. o NC 30/5/1/1/2/2105PR (NC10445PR): A prospecting right renewal and a Section 102 (addition of
further minerals), have been granted to Repli, in terms of section 17(1) of the MPRDA for
copper, zinc, lead, silver, gold, sulphur, cobalt, barytes, limestone, stone aggregate, gravel,
sulphur in pyrite, pyrite, molybdenum ore, tungsten ore, sand (general) and iron ore in respect
of the farm Vogelstruis Bult No 104, portion RE25 and portion 26 and the farm Slimes Dam 154, in
the Prieska District, Northern Cape Province. The date of expiry is 2 November 2019 by which
time Repli is anticipating having been granted the Mining Right which has been applied for.
o Orion effectively holds a 73.3% interest in the project, with the remaining 26.7% as BEE ownership
in compliance with existing legislation.
Vardocube Prospecting Right:
o NC 30/5/1/1/2/11841PR: Vardocube has been awarded a prospecting right, in terms of section
17(1) of the MPRDA, for copper ore, zinc ore, lead, gold, cobalt, sulphur in pyrite, barytes,
limestone, pyrite, tungsten and molybdenum in respect of the farm Vogelstruis Bult No 104,
portion RE1 in the Prieska District, Northern Cape Province. The date of grant is 25 April 2018;
valid for five (5) years. The Prospecting Right has been notarially executed and registration is in
process.
o Orion effectively holds a 70% interest in the Vardocube Prospecting Right, with the remaining
30% as BEE ownership in compliance with existing legislation.
Repli Mining Right Application
o Mining Right: NC30/5/1/2/2/10138MR. The Repli Mining Right Application (MRA), in terms of
Section 22 of the MPRDA, 2002, for the Repli Prospecting area and commodities was submitted
to the authorities, together with the pre-requisite EA application, on 6 April 2018. The application
includes the proposed Mine Works Program and the SLP. The MRA application has been
officially accepted and is in process.
Vardocube Mining Right Application
o Mining Right: NC30/5/1/2/2/10146MR. The Vardocube Mining Right Application (MRA), in terms
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Criteria JORC Code explanation Commentary
of Section 22 of the MPRDA, 2002, for the Repli Prospecting area and commodities was
submitted to the authorities, together with the pre-requisite EA application, on 27 September
2018. The application includes the proposed Mine Works Program and the SLP. The MRA
application is in process.
• Tenure Compliance: At the time of writing, the prospecting rights were compliant with statutory fee
payments, annual reporting and financial provision audits up to date.
• According to the Department of Land Restitution and Reform, there are no land claims on any of the
properties covered by the prospecting rights.
• The Conditional Closure Certificate is discussed under “environmental”, above.
• Government and statutory approvals: There are reasonable grounds to expect that all necessary
government approvals will be received within the timeframes anticipated in the Scoping Study.
• Status of government agreements: Apart from the tenement status (addressed above) the Company
is not aware of any government agreements necessary for the project to continue.
• Discussions continue with the South African Department of Science and Technology to ensure
compliance with technical aspects which may impact on the Square Kilometre Array (“SKA”) radio
telescope, being built near Carnarvon over 40km from the Project.
• In 1987, Armaments Corporation of South Africa (SOC) Ltd (“Armscor”), a State-owned enterprise for
acquiring defence capabilities for the South African Defence Force and other State agencies,
established the Alkantpan ballistic test range on ground neighbouring the Project area (“Alkantpan”)
These surface rights are unlikely to interfere with mine development and operating activities.
• Unresolved matters with 3rd parties which would materially affect the results of the Scoping Study –
none.
Classification • The basis for the classification of the Ore Reserves into • Ore Reserves have not been classified and reported.
varying confidence categories. • Section 4 of JORC Table 1 is being completed as part of the Scoping Study requirement to disclose a
• Whether the result appropriately reflects the competent conceptual Production Target estimate linked to forecast financial information.
Person’s view of the deposit.
• The proportion of Probable Ore Reserves that have been
derived from Measured Mineral Resources (if any).
Audits or reviews • The results of any audits or reviews of the Ore Reserve • No audits or reviews of the ore reserves have been undertaken.
estimates.
Discussion of relative • Where appropriate a statement of the relative accuracy • Ore Reserves have not been classified and reported.
accuracy/confidence and confidence level in the Ore Reserve estimate using • The level of accuracy for the Scoping Study Technical Report is ± 35%.
an approach or procedure deemed appropriate by the • The level of confidence for the preliminary estimates used in the conceptual production schedule is
Competent Person. For example, the application of too low to classify and report Ore Reserves in terms of JORC 2012.
statistical or geostatistical procedures to quantify the • For the Deep Sulphide Mineral Resource (underground mining), a 64% Indicated Mineral Resource
relative accuracy of the reserve within stated and 36% Inferred Mineral Resource was used for the purposes of the Scoping Study. The Company is
confidence limits, or, if such an approach is not deemed confident in using the Inferred Mineral Resource to guide the Scoping Study process as it has
appropriate, a qualitative discussion of the factors which considered that this Mineral Resource is a continuation of a historically-mined deposit and a large
would affect the relative accuracy and confidence of amount of infrastructure remains on site - which lends confidence to the assumption made that the
the estimate. Mineral Resource has the potential to be economically mined.
• The statement should specify whether it relates to global • Mining studies in preparation for a Bankable Feasibility Study are in progress.
or local estimates, and, if local, state the relevant • A sensitivity analysis has been included in the Scoping Study and is included in the “economic”
tonnages, which should be relevant to technical and section above.
economic evaluation. Documentation should include • The data compares very favourably with historical production records for the Anglovaal Prieska
assumptions made and procedures used. Copper Mine which operated between 1971 and 1991 on the Prieska Copper Project.
• Accuracy and confidence discussions should extend to
specific discussions of any applied Modifying Factors that
may have material impact on Ore Reserve viability, or for
which there are remaining areas of uncertainty at the
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Criteria JORC Code explanation Commentary
current study stage.
• It is recognised that this may not be possible or
appropriate in all circumstances. These statements of
relative accuracy and confidence of the estimate
should be compared with production data, where
available.
41
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