South Crofty’s Tin Economics Have Changed Dramatically, but Cornish Metals Still Has a $161 Million Financing Test

For much of its recent history, the investment case around Cornish Metals was relatively straightforward.

Could the company successfully restart the historic South Crofty tin mine in Cornwall after almost three decades of closure?

That question is gradually changing.

The mine is already undergoing physical redevelopment. Dewatering has reached approximately 360 metres below surface, a depth not reached for more than 28 years. Shaft refurbishment is progressing, process-plant engineering is underway, surface infrastructure is being built, and process-plant excavation had reached approximately 80% completion by September.

Cornish Metals continues to target first tin concentrate production in mid-2028.

The more immediate question is now financial.

The company has arranged a substantial portion of the debt needed to develop South Crofty, but cannot access most of that money until it completes a large equity financing.

The project's underlying commodity economics have improved dramatically at precisely the time when financing execution has become its principal constraint.

Tin Prices Have Moved Far Beyond the PEA Assumption

The most important change since Cornish Metals published its updated preliminary economic assessment in September 2025 is the tin price.

The PEA assumed $33,900 per tonne.

The London Metal Exchange official cash price for tin was $54,025 bid and $54,050 ask on September 25, 2026, the latest official LME price available before publication.

That is approximately 59% above the PEA assumption.

*Cornish Metals' £550 million estimate used the June 30 spot tin price of approximately $56,600/t and period-end exchange rates, rather than the September 25 LME price.

The sensitivity is substantial.

At the original $33,900-per-tonne assumption, the 2025 South Crofty PEA generated a £180 million post-tax NPV at a 6% discount rate and a 20% IRR.

At the approximately $56,600 spot price prevailing on June 30, Cornish Metals estimated that the same project framework would produce a post-tax NPV6 of roughly £550 million.

That is more than three times the PEA valuation.

It does not constitute a new feasibility study, and investors should not treat it as one. Capital costs, operating assumptions, exchange rates, development schedules and other inputs can change before production.

But it demonstrates how strongly South Crofty is leveraged to the tin price.

The Margin Structure Explains the Sensitivity

South Crofty is expected to produce approximately 4,700 tonnes of tin-in-concentrate annually during years two through six.

The PEA estimated an all-in sustaining cost of approximately $13,400 per tonne over that period.

At the September 25 LME cash price of roughly $54,050 per tonne, the difference between the metal price and the PEA AISC is more than $40,000 per tonne.

That is not equivalent to mine-level profit. Concentrate payability, treatment charges, royalties, taxes, sustaining capital, corporate costs and other items must still be considered.

But the scale of the difference illustrates why the project's modeled value moves rapidly when tin prices increase.

Using the PEA production rate simply as an operating reference:

The $254 million figure is not a revenue forecast because tin-in-concentrate does not receive the full refined-metal benchmark price.

It is useful instead as a measure of the commodity exposure embedded in the project.

The Tin Market Is Supporting the Project

South Crofty is benefiting from more than company-specific progress.

Tin supply remains geographically concentrated.

Cornish Metals estimates that approximately two-thirds of mined tin originates from China, Myanmar and Indonesia. The company also notes that Asia accounts for well over half of mined production and approximately 80% of refined production.

Independent USGS data support the concentration.

China accounted for approximately 24% of global mined tin production in 2024, while Indonesia produced roughly 55,000 tonnes that year. Myanmar produced approximately 20,000 tonnes, although output fell sharply following disruption in the Wa region.

Myanmar is particularly important because the Man Maw mining district has historically supplied a meaningful portion of Chinese tin concentrate imports.

Supply concentration matters because tin is difficult to remove from one of its largest applications: solder.

Electronics, semiconductors, data infrastructure, solar equipment and broader electrification all require large quantities of solder, creating a direct connection between technology-sector growth and tin demand.

South Crofty would therefore enter production into a market where Europe and North America currently have no primary tin production.

South Crofty Would Still Be Small Globally, but Strategically Relevant

A 4,700-tonne annual operation is not large compared with global base-metal mines.

Tin is different because the global market itself is relatively small.

Cornish Metals estimates South Crofty's expected production would represent approximately 1.5% of global mined tin supply.

That would make the mine strategically more significant than its absolute tonnage suggests.

The project also sits in an unusual jurisdictional position.

South Crofty is:

• located in the United Kingdom;
• already permitted for underground mining through 2071;
• permitted for a new processing facility and required site infrastructure;
• expected to operate without surface tailings;
• potentially the first primary tin producer in Europe or North America; and
• targeting lowest-quartile operating costs based on the current PEA.

This combination helps explain why governments have become increasingly involved in its financing.

Government Capital Is Already Embedded in the Funding Structure

South Crofty is increasingly an example of how Western critical-mineral policy is moving from grants and policy statements toward direct capital support.

The UK's National Wealth Fund previously invested £28.6 million of equity in Cornish Metals and this year agreed to provide up to £35 million of additional secured financing.

Together with Vision Blue Resources, Cornish Metals has access to approximately £52 million of secured credit facilities.

The U.S. government is also considering involvement.

The U.S. Export-Import Bank has provided Cornish Metals with a non-binding Letter of Interest indicating capacity to consider up to $225 million of financing through its Supply Chain Resiliency Initiative.

That fits within the broader UK-U.S. critical-minerals agreement signed in February, which specifically seeks to expand secure mining and processing capacity for materials required by commercial and defense industries.

The strategic logic is straightforward.

A Western tin mine does not eliminate dependence on Asian supply, but it introduces geographically diversified primary production into a supply chain where essentially none currently exists in Europe or North America.

But the $210 Million Bond Is Not Yet Available

This is the most important financial detail in the investment case.

Cornish Metals successfully placed an oversubscribed $210 million senior secured bond in May.

The financing appears substantial relative to the PEA's £198 million pre-production capital estimate.

But the headline number is misleading if viewed as immediately available liquidity.

The bond proceeds are currently held in escrow.

At June 30, Cornish Metals reported $215.8 million of bond proceeds in escrow, including amounts associated with the financing structure. The company cannot access those funds until specified conditions precedent are satisfied.

The most significant condition is an equity financing of at least:

$161 million.

Until that happens, more than $200 million of arranged debt does not fund construction.

That makes the equity raise the central near-term corporate event.

The Financing Requirement Is Large Relative to Cornish Metals' Equity Value

Cornish Metals had a market capitalization of approximately £130 million at the September 25 close.

A required $161 million equity raise therefore represents a very substantial amount relative to the company's current public-market capitalization.

Using a rough GBP/USD conversion simply for scale, the required equity financing is of a similar order of magnitude to the company's entire existing market value.

That creates the central tension in the investment case.

A large equity financing can create substantial dilution.

But the other side of the equation is equally important: the modeled value of the underlying project has increased sharply as tin prices have risen.

The financing discussion therefore cannot be analyzed solely by looking at the size of the proposed equity raise.

The relevant question is what percentage of the project's economic value existing shareholders retain after the complete financing package is assembled.

High-Cost Debt Makes the Capital Structure Important Even After the Equity Raise

The bond itself is not inexpensive.

It carries a 13.5% fixed annual coupon, payable quarterly, has a six-year tenor and was issued at 98% of nominal value. It matures at 103.5% of nominal value.

There are no principal repayments for the first 48 months. After that, quarterly amortization begins, with a 60% bullet payment remaining at maturity.

The secured shareholder facilities are also expensive.

They carry 13.0% annual interest, capitalized and compounded daily, although these facilities are designed primarily as bridge financing and become repayable following a qualifying equity raise.

This is another reason the current tin price matters.

Higher commodity prices do not simply improve the theoretical NPV. They increase the project's potential capacity to support a relatively expensive financing structure.

If tin prices were to fall materially toward the PEA assumption before production, the economics would still remain positive under the PEA, but the margin available to service debt would narrow substantially.

Construction Is Advancing Before the Full Financing Package Is Complete

Cornish Metals is not waiting for the final equity raise before progressing the asset.

As of its September update:

• process-plant excavation was approximately 80% complete;
• the new workshop and stores facility had been completed;
• mine dewatering was progressing toward the 400-level, approximately 730 metres below surface;
• shaft refurbishment was continuing;
• detailed process-plant engineering was underway;
• long-lead equipment procurement had started;
• Roskear West exploration drilling was active; and
• construction of the process plant remained scheduled to begin in the first quarter of 2027.

The company had £14.5 million of unrestricted cash as of September 22, excluding the escrowed bond proceeds.

The second tranche of its shareholder facilities, approximately £20.6 million combined from the National Wealth Fund and Vision Blue, was drawn in August to maintain development activity while the larger financing package is completed.

This reduces the immediate risk that construction simply stops while financing discussions continue.

It does not remove the financing requirement.

Exploration Provides an Additional Variable Outside the PEA

The existing economic study is based on a 14-year mine life.

But South Crofty historically operated for centuries, and the current resource does not necessarily define the ultimate scale of the mineral system.

Cornish Metals has identified a near-mine Exploration Target of approximately 6 million to 13 million tonnes grading 0.5% to 1.8% tin. The company correctly notes that this is conceptual and is not a Mineral Resource.

Recent drilling provides some early evidence that mineralization extends beyond the current resource model.

The first Roskear West drillhole returned:

Several intercepts were outside the current Mineral Resource Estimate, while mineralization remains open to the west.

For investors, exploration is therefore useful optionality rather than something that should be capitalized fully into the present valuation.

The immediate value driver remains financing and construction.

The Equity Raise Is Now More Important Than Another Tin-Price Move

At this stage, another $2,000 or $3,000 move in the tin price probably matters less to the near-term equity story than the structure of Cornish Metals' final financing package.

The key questions are now:

1. At what valuation can Cornish Metals raise at least $161 million of equity?
2. Will strategic investors or offtakers participate?
3. Does U.S. EXIM financing become part of the final capital structure?
4. How much of the existing high-cost debt remains after project financing is finalized?
5. Can construction stay on schedule for mid-2028 production?
6. How much dilution will existing shareholders absorb before the project reaches cash generation?

Those variables will determine how much of South Crofty's improved commodity economics ultimately accrue to current shareholders.

The Investor Takeaway

South Crofty illustrates an increasingly important distinction in critical-minerals investing.

A strategically important mineral deposit can have attractive economics, government backing, permits and strong commodity prices and still face a difficult transition from project value to shareholder value.

Cornish Metals has made considerable progress.

Tin was approximately $54,050 per tonne on September 25, compared with the $33,900 assumption used in the 2025 PEA. The company estimates that the project's post-tax NPV6 increased from £180 million to approximately £550 million when calculated using the June 30 tin price and exchange rates. Construction is advancing, the mine is being dewatered, and the project could introduce meaningful primary tin production into a Western supply chain that currently has essentially none.

But the balance between asset value and financing risk remains unusually visible.

Cornish Metals has already placed $210 million of secured bonds, yet the money remains inaccessible until the company completes at least $161 million of equity financing. Its current market capitalization is only around £130 million.

That means the next major value-creating event is unlikely to be another engineering milestone.

It is whether Cornish Metals can convert stronger tin economics and government interest into a financing package that unlocks construction capital without transferring too much of the project's upside away from existing shareholders.