GREAT WESTERN MINING CORPORATION PLC

("Great Western", "GWM" or the "Company")

Metallurgical Test Work Underway at Tungsten Project

Great Western Mining Corporation PLC (AIM: GWMO & ESM: 8GW), the exploration and development company focused on mineral projects in Nevada, USA, is pleased to announce that it is undertaking proof-of-concept flotation test work on material from its Defender - Pine Crow Tungsten Project ("Defender - Pine Crow" or the "Project") in Mineral County, Nevada.

HIGHLIGHTS

·    Eriez Global of Erie, Pennsylvania appointed to conduct flotation test work on a 750 kg bulk sample from Defender - Pine Crow.

·    Programme to target scheelite mineralisation in skarn host rocks, applying a proven flowsheet to produce a high-grade tungsten ore concentrate with high recovery.

·    Test work to validate processing potential and advance the Project as a US-based tungsten opportunity

·    Assay results, expected in Q3 2026, to contribute towards maiden Mineral Resource Estimation ("MRE") targeted for Q4 2026.

Great Western CEO, Ed Loye, commented: "Engaging Eriez to undertake this test work represents an important step forward in validating the metallurgical characteristics of the mineralisation at Defender - Pine Crow. By applying an established flowsheet to a representative bulk sample, we aim to confirm the suitability of conventional flotation techniques for scheelite recovery.

"We are conducting this work alongside several other activities at the Project, including geophysics, mapping and trenching, all ahead of the fully funded drill campaign scheduled to commence in July 2026.  This highlights the team's confidence in the near-term potential for Defender - Pine Crow and our eagerness to expedite exploration efforts and advance towards a maiden MRE this year."

DETAILS

Metallurgical Test Work Programme

The Company has dispatched a 750 kg bulk sample of run-of-mine material from the Defender - Pine Crow opencut mines to Eriez in Erie, Pennsylvania. The sample is representative of scheelite-bearing skarn mineralisation observed at surface in previously active open-pit mines abandoned after the cessation of WWII.

Eriez will undertake proof-of-concept flotation test work using a pre-existing flowsheet applicable to this style of tungsten mineralisation. The programme is designed to assess recovery characteristics, concentrate grades and overall processing response of the material.

The work will be carried out at Eriez's Pennsylvania laboratory, a well-established facility known for metallurgical process development and simulation across a range of mineral systems.

Results from this test work will contribute to the Company's understanding of the processing pathways available for Defender - Pine Crow and will inform future metallurgical and processing workstreams.

Background

The Defender and Pine Crow tungsten skarns are located approximately 3 km northeast of and on trend with the Company's M2 skarn copper resource in Mineral County, Nevada. Historic production of tungsten from these skarns dates back to a short period during the Second World War.

Following earlier positive field mapping and grab sampling, in December 2025 the Company undertook a machine-cut channel sampling programme at Defender. Two channels returned significant tungsten mineralisation, including 6 m at 0.17% WO₃, including 1 m at 0.43% WO₃, and 16 m at 0.30% WO₃, including 2 m at 0.66% WO₃ (see RNS dated 29 January 2026). Importantly, elements that could represent potential processing penalties were recorded at very low concentrations, and silver mineralisation was also intersected within Channel B.

The Company launched a fully funded expanded exploration programme at Defender - Pine Crow during Q1 2026 to accelerate progress towards defining a maiden MRE and test its scale, continuity and geometry of the mineralised system.  This work also includes testing the potential geological relationship of Defender - Pine Crow to the broader mineralised trend extending towards M2, located more than 3 km to the southwest.

Further announcements will be made in due course.

**ENDS**

Notes

Great Western Mining Corporation PLC (AIM: GWMO / Euronext Growth: 8GW) is an exploration and development company focused on strategic minerals across several 100%-owned claim groups in Mineral County, Nevada, a highly prospective and mining-friendly jurisdiction. The Company has an increasing strategic emphasis on tungsten as a critical mineral, while continuing to advance its Huntoon Copper Project, which hosts a JORC-compliant resource of 4.3 Mt at 0.45% Cu with further porphyry upside. It also maintains exposure to gold and silver through exploration and tailings reprocessing opportunities, alongside evaluating farm-out and joint venture options to unlock wider portfolio value.