Cornish Metals’ $225M EXIM backing: South Crofty tin project economics for engineers
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Cornish Metals has received a letter of interest from the US Export-Import Bank for up to $225 million in financing to restart the historic South Crofty tin mine in Cornwall, conditional on supplying “responsible” tin to the US electronics sector. South Crofty hosts 2.9 million indicated tonnes at 1.5% tin and 2.63 million inferred tonnes at 1.42% tin, with a PEA outlining a 14-year life, average 4,700 t/y tin output and £198 million pre-production capex. The project’s after-tax NPV6 is £180 million with a 20% IRR and 3.3-year payback, with EXIM funding potentially covering almost all initial capital.
Technical Brief
- EXIM’s letter of interest specifies funding is conditional on supplying “responsible” tin to US buyers.
- South Crofty is described by Cornish Metals as the highest-grade tin deposit currently not in production.
- Near-mine exploration target is 6–13 Mt grading 0.5–1.8% Sn, offering potential mine-life extension.
- Peak tin production is scheduled for year 4 of operations at 5,000 t/y Sn.
- EXIM support is framed as a step towards a final investment decision, not yet committed debt.
Our Take
The potential US EXIM financing for Cornish Metals is roughly in line with the South Crofty PEA after-tax NPV6 of $235 million, which typically gives lenders room for full project debt coverage while still leaving equity with meaningful upside in a conventional project finance structure.
With pre-production capital at £198 million versus a market capitalisation of about £161.9 million, South Crofty remains in the classic junior position where external debt or strategic capital is essential; the EXIM interest, if converted, could materially reduce dilution pressure on existing shareholders such as Vision Blue Resources.
A 14‑year mine life and a 3.3‑year payback in the PEA suggest South Crofty could sit in the lower half of the cost curve for Western tin supply, which is significant given our database shows most tin and critical minerals stories still centre on Asian supply hubs like China, Myanmar and Indonesia.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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