Operations Update For The South Crofty Tin Project

Cornish Metals plc (AIM: TIN) (“Cornish Metals” or the “Company”), a mineral exploration and development company focused on advancing its wholly owned and permitted South Crofty tin project in Cornwall, United Kingdom, is pleased to provide an update on the progress of activities at South Crofty.

Highlights

Market conditions remain robust and the current tin price of approximately US$53,000 /tonne further supports the South Crofty project economics with the NPV6% at current spot market prices estimated at approximately £500 million[1]

Surface civil works at Roskear shaft are complete, with the winder house under construction

New workshop and stores facility is nearing completion, with minor exterior works and landscaping remaining

Construction activities for the north and south winders infrastructure are underway to support planned winder mechanical installation in H2 2026

New Cook’s Kitchen (“NCK”) offices are now open with upgraded security, site access and welfare facilities completed

Front-End Engineering Design (“FEED”) of the process plant completed with Detailed Engineering being progressed, with both engagements led by Ausenco

Excavation at the pre-concentration building is approximately 50% complete, with civil works expected to continue as planned throughout 2026

Dewatering underway through the fully commissioned 195-level pump station

Development at the 25-level is advancing, with employee training ongoing

FEED for the underground loading, unloading and hoisting infrastructure is being progressed by Optimult

Orders being placed for long-lead items including shaking tables for the process plant and skips and cages for the NCK shaft

Don Turvey, CEO of Cornish Metals commented:

“I am pleased to report continued strong progress across multiple workstreams at South Crofty. On surface, our new NCK offices are now operational, while construction of the workshop and stores building is nearing completion. Activity at Roskear has also intensified, with erection of the winder house well advanced and early-stage shaft refurbishment commencing. Further, the completion of FEED for the process plant marks a significant step in advancing the project.

“Underground activities are progressing with dewatering underway through the fully commissioned 195-level pump station for the first time in over 28 years. Development at the 25-level continues to advance and is also being used as a training facility for newly recruited employees. As we continue to grow the team, developing a skilled workforce remains a key priority to ensure South Crofty is well positioned as it transitions through development and into production.”

Surface activities

Surface activity at South Crofty continues at pace with several significant milestones achieved as the project advances towards operational readiness.

Construction of the new workshop and stores building at the site of the former Bartles Foundry is nearly complete with only minor exterior works and landscaping remaining. The facility will provide permanent maintenance, storage and engineering support infrastructure for the mine, with completion expected in the coming weeks.

Image 1: Workshop and stores building is nearing completion.

In addition, the new NCK offices are now operational, providing improved modern working facilities for the expanding on-site team. Several site infrastructure and security upgrades have also been completed.

At Roskear, surface activities have progressed in parallel with underground works. Earthworks, foundation, the primary steel structure and building cladding installation for the winder house are now complete.

Image 2: Roskear shaft winder house.

At NCK shaft, civil works within the winder foundation area for the production and service winders have also commenced, supporting the planned equipment mechanical installation programme during the second half of 2026.

The second phase of excavation for the new pre-concentration plant has reached 50% of completion and is progressing according to plan, with civil works expected to continue throughout the year. In parallel, FEED for the process plant has been completed, representing a significant milestone in advancing the project's engineering definition and construction readiness. Ausenco is responsible for the engineering design of the process facilities, while Paterson & Cooke is leading the backfill paste plant design. Overall engineering completion is expected by year-end.

Image 3: Pre-concentration plant excavation.

Across the surface programme, the scale and pace of activity reflects the Company’s continued disciplined and methodical approach to advancing South Crofty. With multiple workstreams progressing simultaneously, meaningful progress has been achieved across infrastructure, facilities and site preparation activities, supporting the next phase of construction and development.

Underground activities

Underground works at South Crofty are progressing across multiple workstreams, advancing the physical development of South Crofty’s underground infrastructure in parallel with ongoing engineering design activities. At NCK shaft, dewatering is ongoing and on-track towards the 400-level (approximately 730 metres below surface) in H1 2027. Refurbishment activities are progressing, including engineering design work for the shaft infrastructure across all key workstreams. Pre-production development at the 290-level (approximately 530 metres below surface) is now expected to commence in Q4 2026, from Q3 2026, with the underground drilling programme also set to start shortly thereafter.

Development from the Tuckingmill decline at the 25-Level, approximately 45 metres below surface, continues alongside training activities for recently recruited miners. The 25-Level development serves multiple purposes within the overall project plan, including establishing future rock-handling and skip discharge infrastructure and supporting workforce capability development. Building a skilled and experienced workforce alongside critical mine infrastructure remains a core priority for the Company, ensuring the operational team is well prepared ahead of South Crofty returning to production.

Image 4: 25-Level underground development.

At Roskear shaft, located approximately 850 metres west of the NCK shaft, early-stage refurbishment preparations continue to advance with scaffolding in place, the shaft cover removed and work platforms being installed. Roskear shaft is planned to serve as the mine’s primary ventilation shaft and secondary means of egress.

Image 5: Roskear shaft.

Corporate

The Company continues to make good progress with the appointment of an independent Non-Executive Director following Ken Armstrong’s retirement from the Board, and is now in the final stages of the recruitment process. The Board expects to announce the successful candidate in due course and looks forward to further strengthening its governance and expertise.

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