Midgee Uranium Project

Stellar Resources Limited, via its wholly owned subsidiary Hitaba Gold Pty Ltd, holds Exploration Licence EL 6350 over the Midgee Uranium Project on Eyre Peninsular, South Australia.

EL6350 reached the end of its initial 2 year licence term on 25 March 2021. Stellar has applied for a further 2 year renewal of EL6350 in February 2020, relinquishing the previously held 73km2 area to a retained area of 38 km2. The renewal application is currently being processed by Department for Energy and Mining, SA.

On 18th May 2021, Stellar entered into a Binding Term Sheet with Alligator Energy Limited (ASX:AGE, or “Alligator”) to sell EL6350 for a total consideration of 7,105,263AGE shares.  Key terms of the Binding Term Sheet signed between Stellar and Alligator include:

  • Stellar’s 100% owned subsidiary, Hiltaba Gold Pty Ltd has agreed to sell EL6350 to Alligator’s 100% owned subsidiary, S Uranium Pty Ltd (SUPL) for a total consideration of 7,105,263 AGE shares.
  • The transaction is subject to obtaining necessary regulatory approvals including;
    • Approval of the EL6350 renewal application lodged on 19th February 2021 by the South Australian Department for Energy and Mining (DEM), and
    • Ministerial approval of the transfer of EL6350 to SUPL.
  • The issue of Alligator shares payable to Stellar under the transaction is subject to approval by AGE shareholders at an Extraordinary General Meeting targeted to be held at the end of June 2021.
  • The transaction is also subject to Hiltaba completing all 2020/21 compliance reporting obligations to DEM which are due by 25 May 2021.
  • Alligator will assume all tenement expenditure commitments and liabilities in relation to EL6350 at the time the transaction completes and will also cover annual rentals and other costs from the date of executing the Binding Terms Sheet.

Results of the 2010 drilling on EL6350 indicate that the licence is unlikely to have the potential to support a stand-alone project and as such is a non-core asset for Stellar. Stellar will benefit from the 7.1M AGE to be paid as consideration for the transaction providing an investment exposure to the uranium sector and to Alligators exciting portfolio of projects. The sale will also result in savings to Stellar in expenditure commitments and tenement management costs for EL6350 moving forward.

The retained 38 kmarea of EL6350 under renewal application contains two geologically and physically distinct blocks: the NE Block and the SW Block

NE Block

The north east block is prospective for southern continuations of the known Plumbush sediment hosted uranium deposit (north of the EL boundary within EL 5926 held by Alligator Energy Limited). Previous rotary mud drilling completed by Stellar’s JV partner in 2010, UraniumSA Limited, intersected potentially economic sediment hosted uranium mineralisation in a number of holes within the northern part of the NE block.

Hole MRM136 provided the best result with an intersection of 7.6m at 0.041% eU3O8, including 1.4m grading 0.106% eU3O8. Hole MRM137, 800m to the east of MRM136 recorded an intersection of 5.0m grading 0.032% eU3O8. Other significant intersections included: MRM128 (2.9m grading 0.016% eU3O8), MRM127 (0.7m grading 0.039% eU3O8), and MRM138 (0.5m grading 0.014% eU3O8).

SW Block

A south-western block which is prospective for uranium and base metals mineralisation associated with the Hiltaba age Charleston granite.

EL6350 – February 2021 Renewal Application Tenement Location Map

EL6350 Midgee: NE Block 2010 USA Drilling with best intercept U3O8 grades

 

North East Tasmania Gold Exploration Project

NE Tasmania – A Continuation of Victorian Western Lachlan Fold Belt

Gold deposits in North East Tasmania lie within a continuation of the Western Lachlan Fold Belt in Victoria – one of the world’s largest orogenic gold provinces.

The Western Lachlan Fold Belt in Victoria hosts the >3 MOz Fosterville Mine, Bendigo and other Tier 1 goldfields and has produced >80 MOz gold.

NE Tasmania hosts the Beaconsfield Mine (2.3 MOz), New Golden Gate Mine (0.3 MOz) and Lefroy Goldfield (0.2MOz), along with hundreds of smaller historic gold mines and occurrences.

While Victoria is currently experiencing intense gold exploration activity, NE Tasmania has had very little modern gold exploration undertaken.

Continuation of Western Lachlan Fold Belt from Victoria into NE Tasmania

Gold deposits in NE Tasmania share the same geological setting as their Victorian counterparts:

  • Ordovician turbiditic meta-sediments (Mathinna Super-Group).
  • Ordovician to Devonian deformation and metamorphism (Western Lachlan Orogen).
  • Associated with nearby Devonian granitoid intrusives.
  • Gold commonly in quartz veins occupying dilational zones along large- scale faults related to folding and deformation during the Lachlan Orogen.
  • Predominantly NW oriented lodes controlled by regional structures and rheological contrasts between sedimentary units.
  • Intrusion Related Gold System (IRSG) deposits also occur in NE Tasmania.

Timing of Geological Events in NE Tasmania vs Melbourne and Bendigo Zone of Western Lachlan Fold Belt in Victoria (after Bierlein et al, 2005)

NE Tasmania Exploration Licence Applications

Stellar has 12 first-in-time Exploration Licence Applications (ELAs) covering an area of 2,534 km2 in NE Tasmania which is highly prospective for Victorian-style and IRGS gold exploration and contains ~77 recorded historic gold occurrences and 25 recorded historic tin occurrences:

  • 10 first-in-time ELAs were registered in September 2020 covering an area of 2,295 km2. These are expected to be granted by the end of June 2021.
  • 2 first-in-time ELAs were registered in March 2021 covering an area of 240 km2. These are expected to be granted later in 2021.

Stellar ELA’s, NE Tasmania Geology and Mineral Occurrences

NE Tasmania Gold Exploration Targets

Numerous gold exploration targets have been identified within Stellar’s ELA’s areas based on the following targeting criteria:

  • Ordovician turbiditic meta-sediments (Mathinna Super-Group)
  • Ordovician to Devonian deformation and metamorphism (Western Lachlan Orogen)
  • Devonian granitoid intrusives nearby
  • Predominantly NW Regional scale structural trends/lineaments identified in aeromagnetic and gravity surveys and corresponding mapped faults. Intersecting NE trends/faults also identified in some of the ELA’s
  • Intrusive Related Gold Style (IRSG) targets identified from aeromagnetic surveys on some ELA’s
  • Location of recorded gold (and tin) occurrences
  • Ground open for application

A number of desktop orogenic and IRGS gold exploration targets have already been identified using full GIS targeting capability developed by Stellar’s technical team including; recently reprocessed aeromagnetic, radiometric and gravity data, geology, recorded gold and tin occurrences, historic drilling and geochemical data. A summary of the gold exploration targets within each of Stellar’s 12 NE Tasmania ELA’s is shown in the table below.

Summary of Stellar NE Tasmania ELA Gold Targets

Proposed Exploration Program

NE Tasmania Gold Exploration Project – Proposed Work Program Summary

2021 Tin Exploration Drilling Program

Phase 1 Drilling Program

A Phase 1 drilling program (~9 diamond holes, ~4,900m) aimed at identifying new areas of high-grade tin mineralisation near the defined Heemskirk tin deposits / resources is being undertaken in 2021 including:

  • Part A – 7 holes targeting depth extensions below key historic silver-lead mines
  • Part B – 2 holes targeting depth extensions of the Severn tin resource

Phase 1 Drilling Program Summary

Phase 1 Part A – Historic Silver-Lead Mines – Depth Extension Drilling

The highly mineralised Zeehan mineral field contains many historically significant high-grade silver-lead mines which have a total recorded production of 26 MOz Silver & 190,000 t Lead and resulted in the development of a major town and smelters at Zeehan in the late 1800’s / early 1900’s.

Part A of the Phase 1 drilling program includes 7 planned holes (total of ~3,000m) aimed at identifying new areas of high-grade tin mineralisation below 4 of the largest historic silver-lead mines in the Zeehan mineral field (Montana No.1, Zeehan Western, Oonah & Zeehan Queen No. 4) which are located on Stellar’s licences and typically had:

  • Ore grades of 20 Oz/t Silver to 100 Oz/t Silver
  • Mining widths of a few cm up to 2.7m (fissure veins)
  • Mining lengths up to 300m
  • Mining depths of 70m to 300m

Silver-Lead lodes typically transition into tin (with pyrite) lodes at depth. The 7 Phase 1 Part A holes target depths below the historically mined silver-lead lodes where transition to tin mineralisation is expected although there is also potential to intersect deeper high-grade silver-lead-zinc fissure lodes. No drilling ever done below these mines.

 

Zeehan Mineral Field – Sn Deposits & Historic Ag-Pb-Zn Mines on simplified Geology

Phase 1 Part B – Severn Resource Depth Extension Drilling

Part B of the Phase 1 drilling program includes two ~700m holes with provision for wedging & daughter holes planned (total of ~1,900m) targeting depth extensions of the Severn tin resource.

Severn is the largest of the Heemskirk Tin Project deposits and has been drilled only to ~500m depth. The 2 holes planned target extension of the Severn deposit ~100m below the current resource limit at a depth of ~600m. Severn remains open at depth where it is hoped that mineralisation will continue and increase in grade towards the underlying granite contact, predicted to be >1,000m below the surface from geophysical surveys.

Phase 2 Drilling Program

A Phase 2 diamond drilling program is under review by Stellar including:

Severn and Queen Hill Indicated Resource Infill Program

Severn and Queen Hill  are the two largest Heemskirk Tin Project deposits with a combined total Mineral Resource of 5.33Mt @ 1.0% Sn, of which 40% is Indicated & 60% Inferred.

The Phase 2 drilling program under review comprises Infill drilling to upgrade a significant part of the Severn and Queen Hill Inferred Resource to an Indicated Resource in order to support a PFS / BFS for the project.

Deep Hole

A deep hole is being considered as part of a Phase 2 drilling program to target the main conduit of mineralising fluids into the Severn and Queen Hill deposits from the underlying interpreted granite.

Advancement of Heemskirk Tin Project to PFS/BFS Completion

Other project work streams and studies required to advance the Heemskirk Tin Project to PFS and BFS completion are also under review by Stellar.

Many of the project work streams and studies have already been completed to a PFS level.

Work towards completion of the DPEMP is well progressed with environmental assessment program agreed and stage 1 surveys completed.

The project has secure Mining Leases granted over mine site, tailings pipeline route and tailings dam site.

Heemskirk Tin Project Scoping Study

Scoping Study Overview

In October 2019, Stellar announced the results of its Heemskirk Tin Project Scoping Study based on development of an underground mine, processing plant, tailings storage facility and surface infrastructure to mine ~ 350ktpa ore at a LOM head grade of ~ 0.95% tin from the Queen Hill and Severn tin deposits (2 of the 4 Heemskirk deposits) over a 10 year initial mine-life. The project also includes open-pit mining of the St Dizier satellite tin deposit and trucking of ore to the Heemskirk processing plant during year 11 of the mine plan.

The processing plant is expected to produce ~ 4,500 tpa of concentrate containing ~ 2,200tpa of tin. Concentrate produced will be trucked 150km to the north via sealed road to the Port of Burnie for export to smelters in Asia.

The Heemskirk Tin Project 2019 Scoping Study was undertaken for the purpose of ascertaining whether a business case can be made to proceed to more definitive studies on the viability of the Heemskirk Tin Project. It is a preliminary technical and economic study of potential project viability based on low level technical and economic assessments that are not sufficient to support the estimation of ore reserves. Further exploration and evaluation work and appropriate studies are required before Stellar will be in a position to estimate any ore reserves or to provide any assurance of an economic development case.

Economic Evaluation

The 2019 Scoping Study confirmed the Heemskirk Tin Project has attractive economics:

  • With a low pre-production capital base of A$57m, the Heemskirk Tin Project generates a pre-tax NPV10% of approximately A$83m (post-tax NPV10% of approximately A$71m), at a tin price of US$20,000/t and 0.70 USD:AUD exchange rate, to an accuracy of ±35%. The pre-tax internal rate of return of the project is approximately 45%.
  • A competitive All-In Sustaining Cost of ~US$13,100/t of tin generates ~34% operating margin based on US$20,000/t tin price and 0.70 USD:AUD exchange rate.

Heemskirk Tin Project – Key Results from 2019 Scoping Study

Sensitivity analysis undertaken as part of the 2019 Scoping Study highlights the robustness and attractiveness of higher tin prices to the Heemskirk Tin Project.

Heemskirk Tin Project – Sensitivity Analysis

Mining

A study of mining the Queen Hill and Severn deposits based on the updated May 2019 Heemskirk mineral resource estimate was completed in September 2019 by technical consultants, Mining One.

Conceptual Heemskirk Mine Design Showing Stopes based on Indicated Mineral Resource (Grey) and Inferred Mineral Resource (Brown)

Key parameters of the mine design selected for the 2019 Scoping Study include:

  • Long hole stoping underground mining method with either Cemented Aggregate Fill or Cemented Rockfill.
  • Mine access via a single decline enabling quick access to Upper Queen Hill, with an initial underground connection access to Severn, followed by an internal decline at Severn and a second connection from Queen Hill to Severn for recovery of upper Severn later in mine life.
  • Mine ventilation provided by using two exhaust shafts and an emergency escape way system designed as a second egress and fresh air intake.
  • Decline dimensions 5mW x 5.5mH
  • Ore drives dimensions 5mW x 4.5mH
  • Stope height 20 m
  • Minimum stope width 2 m
  • Maximum stope width 100 m
  • Strike length 15 m
  • Pillar width 5 m

Heemskirk Tin Project – Preliminary Production Schedule by Resource Category

The preliminary mining schedule for Queen Hill and Severn used in the 2019 Scoping Study includes total mineral resources of 3.29Mt @ 0.95% Sn after application of mining dilution and recovery factors and mining cut-off grades.

For the first 5 years of production and most of year 6, ore is mined from indicated resources. Indicated resources represent 58% of total ore mined over the 11-year life of the project.

Mining of indicated resources from the St Dizier satellite deposit has also been included in the final year (year 11) of the 2019 Scoping Study preliminary mining schedule.

Metallurgy

The Heemskirk Tin Project’s Queen Hill and Severn tin deposits are broadly similar with cassiterite being the principle tin mineral (97% of total tin) in association with coarser grained sulphides (pyrite and pyrrhotite), silicates and carbonates (siderite) and accessory fluorite and rutile. Minor amounts of lead and zinc sulphide occur in the Upper Queen Hill deposit but become less common below 1100RL.

A number of metallurgical test work programs have been completed between 2010 and 2015 on composited drill core samples from the Queen Hill and Severn deposits by ALS Metallurgical Laboratory in Burnie, Tasmania, and supervised by Worley Parsons.

The table below summarises the recovery and concentrate grade estimated from test work completed and the Life of Mine average head grades for each ore type.

Average Head Grade, Recovery and Concentrate Grade by Deposit

Processing Plant and Surface Infrastructure

Due to similarities between ore types, metallurgical test work at Heemskirk and St Dizier has used a modified version of the Renison Tin processing flowsheet. The Renison plant has operated for more than 50 years and under-gone several adaptions over its history to deal with changing ore-types. Such demonstrated flexibility will be a significant advantage for the Heemskirk processing plant.

The flowsheet for the Heemskirk processing plant was designed by GR Engineering and later reviewed by Mincore in July 2016.

Heemskirk Tin Project – Process Flow Diagram  (Mincore)

The main elements of the Heemskirk processing plant flowsheet include:

  • 2 stage crushing followed by grinding (open-circuit rod mill feeding a closed-circuit ball mill)
  • Primary sulphide flotation, regrind of sulphide concentrate and flotation of fine sulphide
  • Coarse and fine gravity separation using spirals and wet tables to produce a concentrate
  • Gravity middling regrind and recycle
  • Flotation of deslimed fine cassiterite
  • Sulphuric acid leach of concentrate to remove carbonate
  • Concentrate dressing using sulphide flotation and magnetic separation

In July 2016, engineering consultants, Mincore, completed plant layout, typical equipment drawings and a +/-35% capital cost estimate for a 200ktpa Heemskirk Processing Plant and Surface Infrastructure.

Mincore were re-engaged by Stellar in August 2019 to scale their June 2016 estimate up to a 350ktpa Heemskirk Processing Plant and Surface Infrastructure capital cost estimate which has been used as the basis for this 2019 Scoping Study.

Opportunities exist for optimisation of the flow sheet and recovery including addition of ore sorting.

Proposed Heemskirk Tin Processing Plant (Mincore 2016)

Tailings Pipeline and Storage

Tailings from the Heemskirk Tin processing plant will be thickened to recover process water and pumped via a 6.7km slurry pipeline to the planned tailings storage facility located within ML 2M/2014. Tailings water is to be reclaimed from the tailings storage facility and pumped back via return water pipeline for use in the process.

An area has been selected for a tailings storage facility located in a concealed valley on crown land with no competing land use and no observed endangered flora or fauna. The site is secured by ML2M/2014 and has no observed geological structures that might make the site unsuitable. The valley is naturally shaped to contain tailings with only a relatively small embankment required to be constructed at the northern limit, minimizing the cost of construction.

Proposed Heemskirk Tailings Storage Facility Plan (Initial Stage) and Site Photograph

Capital Costs

The Heemskirk Tin Project pre-production total capital cost is estimated to be ~A$57M.

Heemskirk Tin Project Capital Cost Summary (±35% accuracy)

Operating Costs

The Heemskirk Tin Project has competitive operating costs of ~A$123/t ore or ~US$13,100/t tin All in Sustaining Cash Cost (AISC).

Heemskirk Tin Project – Operating Costs Summary (±35% accuracy)

Environment

A Stage 1 environmental review of the Heemskirk and St Dizier project areas has been completed by John Miedecke and Partners Pty Ltd. The Stage 1 environmental review concluded that there are no environmental issues that would prevent development of the Heemskirk or St Dizier projects.

Stellar has registered the projects with the Tasmanian Environmental Protection Authority by lodging a notice of intent. The EPA has responded by issuing guidelines for the preparation of a Development Proposal and Environmental Management Plan for each of Heemskirk and St Dizier.

Stage 2 environmental surveying will be conducted in accordance with EPA guidelines and compiled into a DPEMP submission to the EPA and the West Coast Council in support of final mining approvals.

Community

The Heemskirk tin deposits surround Queen Hill a prominent topographical feature (70m elevation above town) that marks the northwest extremity of Zeehan. Housing is sparse on the town side of Queen Hill and non-existent on the northwest side of the hill.

All surface infrastructure including the mine portal, processing plant, surface stockpiles, workshops and offices are sited on the northwest side of Queen Hill above the Trial Harbour Road. The location selected prevents the transmission of noise and dust emissions into the town precinct. Mine access routes are also designed to prevent any interaction between mine vehicles and private vehicles operated within the town.

Underground mine development, particularly of the Severn tin deposit, will extend below the sparsely populated town side of Queen Hill. Much of this activity will occur below 200m from the surface and should have no impact on surface dwellings. Stellar expects to confirm this assessment with vibration and seismic modelling as part of a DPEMP.

Zeehan has a population of 728 people many of whom are involved in the mining industry and would support an increase in mining activity in the area. Stellar has conducted a number of diamond drilling programs on the town side of Queen Hill with the cooperation and support of local residents. The Company also has a good relationship with the West Coast Council who would like to see a Heemskirk workforce making use of the many unoccupied dwellings in the town.

Mount Razorback Exploration Licence

Geology

The style of mineralisation at the historic Razorback Mine is essentially the same as at Renison Mine, located 7km along strike to the north.

The geology of the Razorback Mine is dominated by the Razorback Fault where the Cambrian serpentinite is in faulted contact with the younger Dundas Group Red Lead Conglomerate and Hodge Slate. The Serpentinite has been strongly dolomitized and talc altered within 20-30m of the fault contact.  The sequence strikes north-northwest and is near vertically dipping with the fault dip steep east near surface to steep west dipping below 100m depth.

Tin mineralisation is hosted within the talc-carbonate altered serpentinite and the Red Lead Conglomerate where they are adjacent to the Razorback Fault.  The mineralised lodes are semi continuous and plunge steeply south within the plane of the fault.  Mineralisation consists of semi-massive pyrrhotite with cassiterite, pyrite, arsenopyrite, chalcopyrite, sphalerite and galena.

The lode is wedge shaped with a width of 10-15m at the top (base of pit floor), narrowing to widths of 2-3m at a depth of approximately 100m below the pit floor. The average length of the significant intersections listed in Appendix 1 is 6.4m. The Razorback lode strikes over [200m] and possibly plunges steeply south to over 400m in depth.

Razorback Mine Typical Cross Section 5,363,850mN

Exploration and Mining History

Initial exploration over the Razorback Tin Mine was undertaken from 1958 to 1969 by the Bureau of Mineral Resources and the Tasmanian Mines Department who completed 7 surface diamond drillholes for 528m.

Extensive underground exploration development, 22 underground diamond drillholes (1,009m) and underground bulk sampling was completed over the Razorback Mine by Placer Prospecting Ltd between 1964 and 1966. Placer also completed 16 surface diamond drillholes over the Razorback Mine during this period.

The Razorback Mine was operated as an open pit mine by Minops Pty Ltd from 1975 to 1978 during which time an estimated 180,000 tonnes of ore at ~0.6% Sn was mined and processed by an on-site processing plant and tailings facility.

In 1978 Minops completed a further 7 surface diamond drillholes aimed at locating extensions of the ore to the south of the open cut.

In 1979 a Joint Venture was signed between Minops and CRA Exploration who proceeded to drill 5 deeper surface diamond drillholes over the next few years. In 1982, CRA Exploration decided not to procced further with the project.

In total 35 historic surface diamond drillholes (6,054m) and 22 underground diamond drillholes (1,009m) have been completed over the Razorback Mine between 1958 and 1984.

In 2018, Stellar dug and sampled 3 costeans in the pit floor.

Razorback Mine Long Projection

Razorback Mine Exploration Target

An Exploration Target of 180,000 – 220,000 tonnes @ 0.8 – 1.0% Sn at a cut-off grade of 0.3% Sn has been defined to a depth of 100m below the previously mined Razorback pit floor in accordance with the JORC Code 2012 by technical consultant, Resource and Exploration Geology, in July 2019. There has been no material change to assumptions since the estimate was completed in 2019.

Razorback Mine Exploration Target

It should be noted that this Exploration Target estimate is conceptual in nature. There has been insufficient exploration to define a Mineral Resource in this volume and it is uncertain if further exploration will result in the determination of a Mineral Resource.

Most of the historic drilling, which forms the basis of the Razorback Mine Exploration Target, has only tested mineralisation to a depth of ~150m below the current pit floor. Possible extensions to the Razorback Mine orebody were further identified by CRA Exploration in 1979 after drilling 5 deeper holes. Further drilling of deeper extension targets, such as those identified by CRA Exploration in 1979, have the potential to substantially increase the Razorback Mine Exploration Target.

Razorback Fault and Grand Prize Exploration Potential

There is potential for discovery of further mineralisation along the Razorback Fault over the 7km of strike length between Razorback and Rension and including the Grand Prize Tin deposit, also within Stellar’s Exploration Licence (EL11/201).

The Grand Prize-Razorback Fault structure is a large mineralizing system. Its proximity to the Pine Hill Granite and the Renison Bell Tin Mine make it highly prospective for structural and replacement style tin-copper deposits.

Broad spaced historic exploration of the Grand Prize Fault suggests it is a large mineralizing system, although possibly sub ore grade at this stage. There are ore grade intercepts within the larger low-grade intercepts suggesting there may be some scope for targeting and modelling of higher-grade zones. There is also the possibility of recovering a copper concentrate adding value to the mineralisation. To put it into perspective, the known mineralizing system covers an area twice that of the Severn deposit at Zeehan and remains open down dip.

Razorback – Grand Prize Fault Structure Geological Plan

 

St Dizier Open-Pit Satellite Tin Project

Geology and Exploration History

St Dizier is a satellite open-pit tin deposit located 20km to the northwest of Zeehan. St Dizier is a tin skarn, formed by metasomatic alteration of an original dolomite unit by tin bearing fluids emanating from the Heemskirk Granite. Much of the dolomite is altered to serpentine-magnetite-calc-silicate rock flanked by shales to the south and quartzites to the north. The total meta-sediment package has the form of an east-west trending, vertically dipping roof pendant surrounded by Heemskirk Granite. The skarn consists of magnetite-serpentinite-cassiterite-schoenfliesite-scheelite-bismuthinite. Tin mineralisation is zoned with dominantly cassiterite in the west and increasing amounts of schoenfliesite and other tin species to the east.

43 historic diamond drill holes for 7,309m have been completed at St Dizier over a number of campaigns by different operators. Stellar has completed a further 3 confirmatory diamond drill holes for 317m at St Dizier.

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Plan View of St Dizier Geology

The Indicated Resource at St Dizier includes the West and Central Lodes. The bodies crop-out at the surface and strike east-west over a distance of 400m. They dip vertically to a depth of 200m from the surface (in the case of Central) and vary in width from 3m to 40m. Higher tin grades occur between the surface and a depth of 70m in the Central Lode and grades are higher nearer to the surface making the deposit attractive as a potential low-cost open pit development. The smaller Western Lode could also potentially be considered for open pit mining but has not been included in the mine design at this stage.

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Cross-Section 345,150mE, Central Lode, St Dizier

Resource

A total mineral resource for the St Dizier satellite tin deposit of 2.3mt @ 0.61% Sn (13,786t of contained tin) at a cut-off grade of 0.3% Sn was defined in accordance with the JORC Code 2012 by technical consultant, Resource and Exploration Geology, in March 2014.

St Dizier Mineral Resource Statement (JORC 2012), March 2014

St Dizier Mineral Resource Statement (JORC 2012), March 2014

Mining

A mining study on the St Dizier Deposit completed by Polberro Consulting in July 2015 forms the basis of the mining assumptions used in the 2019 Scoping Study. The Polberro mining study included; pit optimisation, open pit mine design, consideration of geotechnical factors, bench geometry, mine production rate and mining operating and capital costs.

The Polberro St Dizier mining study focused purely on part of the Central Lode Indicated Resource and determined that an open pit mining method which is well suited to the Central Lode mineralisation as it crops out at the surface, has its highest grades within 50m of the surface, occurs as multiple lenses over widths of 3m to 40m and is surrounded by relatively competent wall rocks. It is also the lowest cost mining method available for the style of mineralisation.

Key results from the Polberro St Dizier mining study, used in the 2019 Scoping Study include:

  • In-pit diluted indicated mineral resource of 409,179t @ 0.90% Sn with an average strip ratio of 4.7:1 after application of 10% mining dilution and 95% mining recovery factors
  • 100% Indicated Mineral Resource
  • Mining capital costs of A$3.3m for drainage diversion, pit development and construction of a waste which can be completed within 3 months
  • Mine closure capital cost of A$0.5m
  • Contractor operated mining costs estimated at A$26/t ore mined inclusive of waste removal,
  • Trucking cost of A$5/t for trucking St Dizier ore a distance of 20km to the processing plant at Heemskirk
  • The accuracy of the mining operating cost and capital cost estimates was ±35%

The Heemskirk Tin Project 2019 Scoping Study includes mining from the St Dizier satellite tin deposit which will be mined as an open pit mine and processed in the Heemskirk plant during the last year of the project.

Long Projection St Dizier Tin Deposit

Metallurgy

St Dizier ore is similar in complexity to that at Upper Queen Hill. Stage 1 test work on diamond drill core from St Dizier has been undertaken by ALS Metallurgical Laboratory in Burnie and supervised by Worley Parsons. The test work showed the following outcomes:

  • Mineralisation in the sample was quite variable and provides a wide range of responses
  • High tin losses to magnetite, slime and tin float tails resulted in overall recovery of 43%
  • Gravity concentrate tin grade of 55% is possible through pre-gravity sulphur removal
  • Tin float grade could be significantly upgraded by optimising deslime, talc management and acid leaching of concentrate
  • Stage 2 optimisation has the potential to increase tin recovery up to 50% into a 50% tin in concentrate product

Overview of Tasmanian Tin Projects

Stellar’s 100% owned tin projects have an enviable location within the well-established mining district on the West Coast of Tasmania with access to established infrastructure including nearby water and renewable power, access to the port of Burnie 150km to the north via sealed highway for export of concentrate, and a competitive local market for services, mining and processing inputs and labour.

Stellar’s flagship Heemskirk Tin Project is just 18km to the southwest of the Renison tin mine, the largest and most productive tin mine in Australia. Including Renison, there are 5 major underground metal mines, 3 of which are operating, within 30km of the Heemskirk Tin Project.

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Location of Stellar’s Tin Projects in the West Coast of Tasmania

Stellar holds the following tin licenses in the West Coast of Tasmania near the historic mining town of Zeehan:

  • Heemskirk Tin Mining Lease (ML2023P/M) containing 3 of the 4 Heemskirk Tin Project deposits (Queen Hill, Severn and Montana) and the proposed site for the Heemskirk Tin Project processing plant near Zeehan.
  • Heemskirk Tailings Storage Mining Lease (ML2M/2014) over the tailings storage site for the Heemskirk Tin Project
  • Heemskirk Tailings Pipeline Route Mining Lease (ML2040P/M) over the tailings pipeline route for the Heemskirk Tin Project
  • St Dizier Tin Mining Lease (ML10M/2017) over the St Dizier satellite open-pit tin deposit located 20km to the northwest of Zeehan
  • Montana Flats Exploration License (EL13/2018) containing the Oonah deposit, the fourth of the 4 Heemskirk Tin project deposits, along with significant exploration potential and a number of historic silver-lead-zinc mines and associated tin mineralisation
  • Mount Razorback Exploration License (EL11/2017) containing the historic Razorback Mine, Razorback Mine Tin Exploration Target (a satellite project located 8km east of Zeehan), Razorback Tailings and significant exploration potential

 

Stellar holds the best Portfolio of Tin Assets in Australia with Secure ML’s over Heemskirk and St Dizier and a large EL package providing further upside and flexibility.

Location of Stellar’s Tin Licences around Zeehan, Tasmania

Stellar’s flagship Heemskirk Tin Project includes the Queen Hill, Severn, Montana and Oonah tin deposits.

The Heemskirk Tin Project Scoping Study completed in 2019 is based on development of an underground mine, processing plant, tailings storage facility and surface infrastructure to mine ~ 350ktpa ore from the Queen Hill and Severn tin deposits (2 of the 4 Heemskirk Tin Project deposits) over a 10 year mine-life. The Scoping Study also includes open-pit mining of the St Dizier satellite deposit and trucking to the processing plant at Heemskirk during the final year (year 11) of the project.

Montana Flats Exploration Licence

The Montana Flats Exploration License EL13/2018 was granted to Stellar in August 2018 after a competitive tender process run by Mineral Resources Tasmania for the license.

Montana Flats EL13/2018 includes:

  • The Oonah Mine – a large historic silver-lead mine with a recorded silver production of 2.0 MOz and underlying Oonah Inferred Resource, the fourth of the known Heemskirk Tin Project deposits.
  • The Zeehan Western Mine – one of the largest historic silver-lead mines in the Zeehan field with a recorded silver production of 7.1 MOz.
  • A number of other smaller historic silver-lead mines.
  • The extension of the northwest trending structural corridor along which all tin deposits and major historic silver-lead-zinc mines in the Zeehan field lie, greatly enhancing the exploration potential of the Heemskirk Tin Project.

The 2021 Phase 1 Drilling program includes the following holes located on Montana Flats EL13/2018:

  • 2 holes to be drilled beneath the Oonah Mine and Resource
  • 2 holes to be drilled beneath the Zeehan Western Mine

 

Montana Flats EL13/2018 – Interpretative Geology

Heemskirk Tin Project Geology and Resources

Geology and Exploration

The Heemskirk Tin deposits are granite related cassiterite and basemetal stockwork and replacement style mineralisation hosted in older sediments and volcaniclastics of the Zeehan Sub Basin, Western Tasmania.  Mineralisation is generally stratabound. The stratabound mineralisation is structurally controlled on fold/fault dilation zones between lithologies of contrasting rheology.

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Schematic Geology Cross-Section Showing Queen Hill and Severn Tin Deposits

A total of 58 diamond drillholes (18,709m) have been completed by Stellar over the Heemskirk deposits since 2010. A further 133 historic diamond drillholes (31,485m) have been completed prior to 2010 by other companies over the Heemskirk deposits.

The Heemskirk Tin Project includes 4 deposits which have been defined over a total strike length of approximately 1,300m to depths of <500m below surface.

Orientation, Strike Length, Dip and Thickness of Heemskirk Tin Deposits

Mineralisation in all of the Heemskirk deposits remains open down plunge. Tin occurs principally as cassiterite with minor stannite and base-metal sulphides located towards the top and periphery of the Queen Hill and Montana Deposits.

Mineral Resource

An updated total mineral resource for the Heemskirk tin deposits of 6.6mt @ 1.1% Sn (70,930t of contained Sn) at a cut-off grade of 0.6% Sn has been defined in accordance with the JORC Code 2012 by technical consultant, Resource and Exploration Geology, in May 2019. There has been no material change to assumptions since the resource estimate was completed in 2019.

 

Heemskirk Tin Project Mineral Resource Statement (JORC 2012), May 2019

2.12 Mt of the Heemskirk total mineral resource is in the Indicated Mineral Resource Category and 4.48Mt is in the Inferred Mineral Resource Category.  All deposits have higher grade zones and are amenable to mining at higher cut-off grades. All deposits open at depth.

Heemskirk May 2019 Mineral Resource Model @ 0.6% Sn Cut-off Grade – Indicated Resources highlighted in Red with Inferred Resources in Green

Benchmarking the Heemskirk Tin Project Resource

Heemskirk is the highest grade undeveloped tin resource in Australia and the second highest grade undeveloped tin resource globally.

Comparison with Renison Tin Mine

The Renison Tin Mine located 18km to the NE of Heemskirk has similar geology and ore genesis to the Heemskirk Tin deposits.  Renison started with a 4.0Mt reserve and 5 year mine life in 1968 and has since increased the mine life to 50 years with at least another 15 years to go. The Heemskirk deposits contain only ~20% of contained tin found at Renison to date.

 

Comparison of Heemskirk and Renison Tin Deposits