Heemskirk Tin Project

Stellar’s 100% owned Heemskirk Tin Project is strategically located within the well-established mining town of Zeehan on the West Coast of Tasmania. The Project is close to critical infrastructure  including renewable energy sources (Wind and Hydro), access to the Burnie Port 150k to the north via sealed road providing access to world markets.

The Heemskirk Tin Project includes three nearby tin deposits: Severn, Queen Hill and Montana. Stellar holds secure Mining Leases over the Heemskirk Tin Project including the tailings pipeline route, tailings storage site and also over the St Dizier satellite tin deposit.

In addition to the Heemskirk Tin Project, Stellar owns a portfolio of nearby Exploration Licences including the Montana Flats EL which contains a number of historic silver-lead-zinc mines with associated tin mineralisation, the Oonah tin deposit.

Resource Definition Drilling

Two infill drilling programs were completed at the Severn tin deposit during 2022 and 2023, which focused on increasing the Heemskirk Tin Project Indicated Mineral Resource in wide high-grade areas of the Severn deposit. Severn is the largest of the four deposits in the flagship Heemskirk Tin Project.

Two extensive diamond drill programs were completed at the Severn deposits in September 2022 (Phase 2A) and June 2023 (Phase 2B) totalling 16 holes for ~7,150m, with highlights including:

  • ZS150:
    • 36.6m @ 1.07% Sn from 471.5m inc.
    • 12.0m @ 2.12% Sn from 485m
  • ZS148:
    • 34.9m @ 1.01% Sn from 333m inc.
    • 8.6m @ 1.66% Sn from 333m and
    • 12.7m @ 1.19% Sn from 355.3m
  • ZS156:
    • 42.9m @ 0.77% Sn from 490.1m inc.
    • 15.9m @ 1.27% Sn from 496m
  • ZS162:
    • 20m @ 1.16% Sn from 312m inc.
    • 8m @ 1.56% Sn from 312m and
    • 8m @ 1.34% Sn from 324m

Mineral Resource Estimate

Following the completion of resource drilling an updated Heemskirk Tin Project Total Mineral Resource Estimate (MRE) of 7.48Mt @ 1.04% Sn (77.87kt contained Sn) at a cut-off grade of 0.6% Sn was defined in September 2023 in accordance with the JORC Code 2012. The updated Indicated Mineral Resource of 3.52Mt @ 1.05% Sn (36.99kt contained tin) for Heemskirk represents a 24% increase in contained tin in the from the previous November 2022 MRE and a 58% increase from the 2019 MRE, significantly increasing confidence in the Project.

Heemskirk Tin Project Mineral Resource Statement (2023)

Classification Deposit Resource Date Tonnes (Mt) Sn (%) Contained Sn (t) Cassiterite % of Total Sn (%) Cu (%) Pb (%) Zn (%)
Indicated Upper Queen Hill 2023 0.37 1.07 3,991 88 0.14 1.84 0.72
Lower Queen Hill 2023 0.81 1.30 10,493 97 0.04 0.29 0.35
Severn 2023 2.33 0.96 22,507 98 0.07 0.02 0.03
Sub Total Indicated 3.52 1.05 36,991 97 0.07 0.27 0.18
Inferred Upper Queen Hill 2023 0.14 0.92 1,332 89 0.12 1.7 0.39
Lower Queen Hill 2023 0.77 1.16 8,873 98 0.04 0.21 0.12
Severn 2023 2.37 0.85 20,234 99 0.05 0.02 0.04
Montana 2019 0.68 1.54 10,443 96 0.08 0.72 1.42
Sub Total Inferred 3.96 1.03 40,881 98 0.05 0.23 0.30
Grand Total Heemskirk Tin Project 7.48 1.04 77,872 97 0.06 0.25 0.25

SRZ Announcement – 4 September 2023 – Severn MRE Returns 29% Increase in Contained Tin

2019 Scoping Study Overview

Stellar Resources completed a Scoping Study in October 2019 for the Heemskirk Tin Project, which was based on the development of an underground mine, processing plant, tailings storage facility and surface infrastructure to mine ~350kpta ore at a LOM head grade of ~0.95% Sn from the Queen Hill and Severn 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 ~ 4,500tpa 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 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.

SRZ Announcement – 1 October 2019 – Heemskirk Tin Scoping Study Confirms Attractive Economics

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

AUD:USD Tin Price (US$/t)
Exchange Rate 16,000 18,000 20,000 22,000 24,000
0.76 -9 23 55 88 120
0.73 2 35 69 102 136
0.70 13 48 83 118 153
0.67 26 62 99 135 172
0.64 39 78 116 154 192

St Dizier Open-Pit Satellite Tin Project

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.

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

Classification Tonnes (mt) Sn (%) Contained Sn (t) Cassiterite (%) of Total Sn (%) WO3 (%) Fe (%) S (%)
Indicated 1.20 0.69 8,280 87 0.04 23.70 2.64
Inferred 1.06 0.52 5,512 58 0.05 22.22 1.81
Total Resources 2.26 0.61 13,786 75 0.04 23.00 2.25

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.

Montana Flats Exploration Licence

The Montana Flats Exploration Licence EL13/2018 includes the following:

  • 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.