South Crofty’s updated Preliminary Economic Assessment (PEA) outlines improved project economics and provides additional detail on planned mine developments.

Cornish Metals, a Canadian mine development company focused on restarting the South Crofty Project in Cornwall, UK, published an updated PEA for the project in September 2025, following its initial release in May 2024.

The revised study highlights stronger project economics, with an after-tax net present value (NPV) (at a 6% discount rate) of US$235M and an internal rate of return (IRR) of 20% at a base tin price of US$33,900/t, compared with the previous NPV (at a 8% discount rate) of US$201M and IRR of 29.8% at a base tin price of US$31,000/t. Both economic metrics were calculated over a 14-year life-of-mine.

Cost metrics were also revised, with pre-production capital now estimated at US$257M (up from US$177M in May 2024) and a life-of-mine average all-in sustaining cost of US$14,461/t of payable tin (vs US$13,661/t in May 2024).

Operational metrics remain largely unchanged from the May 2024 PEA. South Crofty is expected to operate for 14 years, with total mine throughput of 500ktpy and processing throughput of 250ktpy.

Minor adjustments include a marginal reduction in total life-of-mine tin production to 49,168t Sn (from 49,310t Sn), with nameplate capacity anticipated by year two. From years two to six, the average output is projected at 4,695tpy Sn, compared with 4,765tpy in the previous assessment.

The updated PEA represents a key milestone for the South Crofty Project, with Cornish Metals targeting commissioning and first production by mid-2028. The tin market has been supported by tight supply conditions following a two-year production halt at Myanmar’s Man Maw Mine, which contributed to elevated prices.

Whilst a resumption of supply from Myanmar is expected in the near term, Project Blue’s medium-term outlook continues to indicate a constrained concentrate market, highlighting the need for supply expansion from both existing producers and new entrants such as Cornish Metals, among others.