Castile Resources has released a robust 2026 Scoping Study for its Rover 1 IOCG project, showcasing strong financial metrics and the strategic inclusion of bismuth as a new revenue stream.
- Two-stage underground mine development with 11-year life
- Inclusion of bismuth adds approximately A$600M in revenue
- Pre-tax NPV8% of A$1.08 billion and IRR of 56.3%
- Five key products: gold, copper, bismuth, cobalt, magnetite
- Initial CAPEX estimated at A$171.6 million
Rover 1 Project's Multi-Metal Strategy Boosts Economics
Castile Resources Limited (ASX:CST) has unveiled the results of its 2026 Scoping Study for the Rover 1 Project, a polymetallic iron oxide copper gold (IOCG) deposit located near Tennant Creek in the Northern Territory. The study models an underground mine with an 11-year life, producing five metals: gold, copper, bismuth, cobalt, and magnetite. Notably, bismuth is included in the economic model for the first time, contributing an additional A$600 million in revenue.
The project’s two-stage development plan starts with an underground mine and a 750,000 tonnes per annum processing plant onsite. Stage Two envisages a refining facility at the Middle Arm Sustainable Development Precinct (MASDP) in Darwin, leveraging cash flows from Stage One to produce refined metals including gold doré, 99% copper cathode, cobalt hydroxide, and high-purity magnetite concentrate.
Strong Financial Metrics Underpin Viability
Financial modelling assumes conservative commodity prices, including a copper price of US$7.50/lb and gold at US$5,000/oz for the base case, with an upside scenario reflecting higher prices. The study estimates a pre-production capital expenditure of A$171.6 million and total project revenues of A$4.81 billion. Operating costs are forecast at A$1.95 billion, yielding a pre-tax net present value (NPV8%) of A$1.08 billion and an internal rate of return (IRR) of 56.3%. Post-tax NPV stands at A$682.8 million with an IRR of 43.3%. Payback is projected within 1 year and 7 months of production start.
The project plans to produce 270,900 ounces of gold, 72,500 tonnes of copper, 5,400 tonnes of bismuth, 2,800 tonnes of cobalt, and over 1.1 million tonnes of magnetite concentrate over the life of mine. The inclusion of bismuth, a critical mineral with a concentrated supply chain and growing strategic demand, underscores the project's alignment with evolving market dynamics.
Market Dynamics and Price Assumptions
Castile’s price assumptions reflect structural supply deficits and demand growth in key metals. Copper and cobalt markets are expected to tighten from 2028 onwards, coinciding with Rover 1’s production window. Bismuth, dominated by Chinese supply, has seen price volatility due to export controls and is forecast to command a premium for non-Chinese certified 4N bismuth. Magnetite from Rover 1 is distinguished by its high purity (96.5% Fe3O4), commanding a premium over standard iron ore products, with demand driven by green steel technologies and industrial applications.
Development Pathway and Funding Outlook
Castile intends to progress to a Bankable Feasibility Study (BFS) later in 2026, building on the scoping study’s foundation. The company plans to commence formal funding negotiations, targeting a mix of debt, equity, and potentially metal streaming or offtake agreements. Preliminary informal discussions with financial institutions have indicated interest, though no formal agreements are in place. The company’s cash balance of A$9.37 million as of June 30, 2026, supports ongoing BFS activities.
Environmental approvals are underway, with an Environmental Impact Statement (EIS) expected by late 2026 and final approvals anticipated 12–18 months thereafter. Castile emphasizes its commitment to sustainable mining practices, including underground mining to minimize surface disturbance and the use of paste fill to reduce tailings footprint.
Exploration Upside and Regional Potential
The Rover 1 deposit remains open at depth, with adjacent deposits Rover 4, Explorer 108, and Explorer 142 offering potential extensions to the project’s life and scale. Exploration continues to target these prospects, aiming to develop a mineral hub in the region. This strategy could enhance the project’s longevity and regional economic impact.
Castile’s Executive Chair and Managing Director Mark Hepburn highlighted the strategic value of the polymetallic approach, stating that the inclusion of bismuth has materially enhanced project economics and that the staged development offers funding flexibility. The company is focused on delivering value for stakeholders while adhering to environmental and social best practices.
Bottom Line?
The Rover 1 Scoping Study sets a solid commercial foundation, but investors should watch the upcoming BFS outcomes and funding progress closely.
Questions in the middle?
- How will final metallurgical testing for bismuth influence the BFS and project economics?
- What funding structures will Castile pursue amid evolving critical minerals market dynamics?
- Could exploration success at adjacent deposits extend Rover 1’s mine life beyond 11 years?