Project life revenue by stream
- GoldA$1,935.2M40%
- CopperA$1,711.5M36%
- BismuthA$595.2M12%
- MagnetiteA$330.7M7%
- CobaltA$233.9M5%
- Total revenueA$4,806.5M100%
Rover 1
The flagship: gold and critical minerals from one deposit.
Rover 1 is a high-grade IOCG deposit 57 km from Tennant Creek. The 2026 Scoping Study models a two-stage development — a 750,000 tpa underground operation producing gold doré, 99% copper, bismuth, cobalt and magnetite, refined downstream at Middle Arm in Darwin — over an 11-year initial mine life.
August 2026 study
What the 2026 Scoping Study concluded.
The 2026 Scoping Study lifts Rover 1 from the 500 ktpa plan of the 2022 PFS to a 750 ktpa steady-state operation over an 11-year initial mine life, with roughly ten years of steady-state production from 2030 to 2039. On base case metal prices it values the project at A$1.08B pre-tax NPV at an 8% discount rate, and pays back the pre-production capital in a little over eighteen months.
- Steady-state rate
- 750 ktpa
- Initial mine life
- 11 yrs
- Payback period
- 1 yr 7 mths
- Material processed
- 7.27 Mt
Up from 500 ktpa in the 2022 PFS
≈ 10 yrs steady state, 2030–2039
From first capital deployment
Life of mine
| Project economics | Units | Scoping study outcome | Upside scoping study outcome |
|---|---|---|---|
| Total revenue | A$M | 4,806.5 | 5,507.5 |
| Project operating costs | A$M | 1,953.8 | 1,952.3 |
| Project cash flow | A$M | 1,941.4 | 2,598.4 |
| Pre-production capital | A$M | 171.6 | 171.6 |
| Underlying mine profit | A$M | 2,070.1 | 2,727.4 |
| NPV @ 8% (pre-tax) | A$M | 1,077.1 | 1,491.4 |
| IRR (pre-tax) | % | 56.3 | 72.3 |
| NPV @ 8% (post-tax) | A$M | 682.8 | 956.9 |
| IRR (post-tax) | % | 43.3 | 55.9 |
- Base case
- US$5,000/oz Au, US$7.50/lb Cu, US$35/lb Bi, US$60,000/t Co, US$210/t Fe₃O₄. Exchange rate US$1.00:A$0.70.
- Upside case
- US$7,667/oz Au, US$7.37/lb Cu, US$42.18/lb Bi, US$88,083/t Co, US$230/t Fe₃O₄. Exchange rate US$1.00:A$0.77.
Metal price assumptions and financial results from ASX:CST, 20 August 2026 — “2026 Rover 1 Scoping Study Produces Outstanding Results”.
Read the full scoping study presentation (PDF)
Sources: “2026 Rover 1 Scoping Study Produces Outstanding Results”, ASX:CST, 20 August 2026 · Mineral Resource update, ASX:CST, 20 October 2025.
Production and cashflow
What an average year looks like.
At steady state the study models 750,000 tonnes of ore a year through the plant, producing around 28,200 ounces of gold, 7,500 tonnes of copper, 500 tonnes of bismuth, 300 tonnes of cobalt and 110,500 tonnes of magnetite — A$479.9M of revenue and A$219.1M of pre-tax cash flow in an average year.
| Summary | Units | Annual average | Initial life of project |
|---|---|---|---|
| Cashflow | |||
| Total revenue | A$M | 479.9 | 4,806.5 |
| Pre-tax cash flow | A$M | 219.1 | 1,941.4 |
| Production | |||
| Total ore mined | t ore | 750,000 | 7,268,800 |
| Gold | oz Au | 28,200 | 270,900 |
| Copper | t Cu | 7,500 | 72,500 |
| Bismuth | t Bi | 500 | 5,400 |
| Magnetite | t Fe₃O₄ | 110,500 | 1,102,300 |
| Cobalt | t Co | 300 | 2,800 |
Production and cashflow summary from ASX:CST, 20 August 2026 — “2026 Rover 1 Scoping Study Produces Outstanding Results”. Base case metal price assumptions as above.
Mineral Resource
What is in the ground.
The October 2025 estimate lifted the Rover 1 JORC 2012 Mineral Resource 41% to 7.86 Mt at 1.35 g/t Au, 1.24% Cu, 0.11% Bi, 0.07% Co and 23.97% Fe₃O₄, and raised every contained metal against the prior estimate. It is the resource the 2026 Bankable Feasibility Study will be built on. The breakdown by Indicated and Inferred category is in the scoping study presentation.
- Gold
- 341.3 koz
- Copper
- 97.4 kt
- Bismuth
- 8,900 t
- Cobalt
- 5,200 t
- Magnetite
- 1.88 Mt
+8% on the prior estimate
+17% on the prior estimate
+51% on the prior estimate
+30% on the prior estimate
+45% on the prior estimate
Rover 1 Mineral Resource Estimate, ASX:CST, 20 October 2025, reported under JORC 2012. Tonnages and grades are rounded; minor computational and summation rounding differences may occur.
Revenue streams
Five products from one orebody.
Downstream products
Finished on Australian soil.
- Gold doré, refined to finished form in Australia.
- 99% copper, produced at the Middle Arm precinct, Darwin.
- 99% cobalt, alongside the copper stream.
- 96.5% magnetite as a saleable product.
- Bismuth concentrate, with China currently producing 83% of global 4N supply.
Sources: “2026 Rover 1 Scoping Study Produces Outstanding Results”, ASX:CST, 20 August 2026 · Mineral Resource update, ASX:CST, 20 October 2025.
Mine to metal
Beneficiate at Tennant Creek, refine in Darwin.
Ore is beneficiated at Rover 1 to a concentrate, then refined downstream at the Middle Arm Sustainable Development Precinct in Darwin. The NT Government awarded the project Major Project Status in April 2024, with land allocated at Middle Arm.
Stage One funds Stage Two: concentrate sales from Tennant Creek pay for the Darwin refinery, so the downstream position is built out of the mine's own cash flow rather than a second raise. Rail, highway, airport and gas all sit near the project.
Geology
Jupiter and the broader Rover 1 system.
Rover 1 is an IOCG polymetallic deposit. The October 2025 Mineral Resource update lifted the JORC Mineral Resource 41% to 7.86 Mt. The orebody is open at depth and to the east, and is mined by long hole open stoping from a decline, at a 750 ktpa production rate.
Project video
A four-minute walk through the case.
Recorded after the 2022 PFS, the video walks through the mining and processing design and the downstream product strategy. The fundamentals are unchanged; the 2026 Scoping Study lifts throughput to 750 ktpa and adds the bismuth case.
Drilling
Bonanza intercepts in the Jupiter lode.
Roughly 90,000 m of diamond drilling defines Rover 1 — about 75,000 m before Castile acquired the ground and 15,000 m since. The best gold intercept is 7 m at 125.93 g/t Au from 542 m; the best copper, 21 m at 6.86% Cu from 469 m.
The 2020 season materially improved the understanding of the higher-grade gold zones within the Jupiter lode, and supported a reinterpretation in which Jupiter Deeps is the depth extension of Jupiter West, continuing through to the Ganymede intercepts. The full intercept tables are in the scoping study presentation.