Mr. Garrett Ainsworth reports

DISTRICT ANNOUNCES PROMISING WATER TREATMENT RESULTS FROM COLLABORATION WITH XOMA AB

District Metals Corp. has released highly encouraging results from collaboration with Swedish water treatment innovator Xoma AB. The joint initiative is focused on advancing effective solutions for the purification of water impacted by metal leaching from mineralized alum shale recovered from the Viken property, located in Jamtland county, central Sweden.

The collaboration underscores District's commitment to working with Swedish-based partners and supporting domestic innovation as the company advances its mineral projects in Sweden. By leveraging Swedish engineering expertise and environmental technology developed specifically for Nordic operating conditions, District aims to create robust solutions that meet or exceed environmental standards and regulations for all of its mineral projects in Sweden.

Preliminary testing evaluated a stepwise microalgae-based purification process using water mixed with mineralized alum shale (leachate) designed to replicate conditions associated with natural alum shale weathering. Under certain environmental conditions, alum shale has potential to mobilize metals into water.

District notes that Boliden Mineral AB and Xoma AB started collaborating in May, 2025, on the evaluation and pilot deployment of Xoma's Flow water treatment technology at Boliden's Ronnskar smelter operation in Sweden.

Strong performance from microalgae treatment

The initial study compared leachate against water treated through one, two and three sequential purification steps, using both single and double doses of microalgae biomass.

Results demonstrated a consistent and substantial reduction in key metal concentrations across all treatment stages. Notably, when a double algae dose was applied, drinking water quality thresholds for central parameters were achieved after just one treatment step for nickel and uranium as shown below in Table 1.

These findings indicate that the treatment process is both effective and responsive, with increased biomass yielding improved purification efficiency and a stronger safety margin.

Scalable and controllable solution

The results confirm that microalgae-based treatment offers a controllable and scalable method for reducing metal concentrations in water. While single-dose treatments delivered strong performance, the enhanced results from double dosing suggest the process is capacity driven, providing valuable insights for optimization and future design.

Next steps

Based on these positive outcomes, District and Xoma will look to advance additional testing as the Viken deposit is developed. Future work may include:

• Increased sample replication;
• Testing across varied water chemistries;
• Monitoring operational parameters such as biomass and treatment duration;
• Simulating continuous-flow systems to support scalability.

These efforts are expected to further refine the process and support its transition toward a real-world application.

Commitment to sustainable innovation

Garrett Ainsworth, chief executive officer of District, commented: "Water stewardship is a central pillar of how we advance our projects, and these results represent a meaningful step forward. We are truly grateful to the team at Xoma AB for their expertise, innovation and strong collaboration throughout this work. Working together with a Swedish technology company such as Xoma AB is particularly meaningful for us as we advance a Swedish project. We strongly believe that local collaboration, innovation and expertise will play an important role in shaping responsible resource development in Sweden.

"The impressive performance of their microalgae-based treatment with achieving key drinking water thresholds at an early stage highlights the potential for a practical, scalable and environmentally responsible solution. As we continue to advance the Viken deposit, partnerships like this are essential and reinforce our commitment to integrating leading-edge technologies that support both responsible mineral resource development and environmental protection."

Mourad Lahdo, chief executive officer of Xoma, commented: "I would like to express my sincere thanks to District Metals for their driven initiative and constructive participation in the project. Their ambition to develop safe, sustainable and circular extraction of uranium and critical metals from Swedish alum shale deposits, with Swedish innovation at its core, is inspiring and well in line with Xoma's vision of environmentally friendly solutions for water treatment."

Technical information

All scientific and technical information in this news release has been prepared by or approved by Garrett Ainsworth, PGeo, president and chief executive officer of the company. Mr. Ainsworth is a qualified person for the purposes of National Instrument 43-101, Standards of Disclosure for Mineral Projects.

All tests have been performed by Xoma and independently analyzed by a third party laboratory (SGS Analytics Sweden) according to standard SS-EN ISO 17294-2:2023. The test water was prepared by adding 40 grams of crushed alum shale to a 20-litre water container. The container was shaken once per day for seven days to allow the alum shale to leach metals into the water. The resulting water was used as leachate water in all purification tests. The prepared leachate water was treated with microalgae in sequential steps. Two dose levels were evaluated: a single algae dose and a double algae dose. Each dose level was tested over one, two and three treatment steps, allowing the stepwise effect of both biomass quantity and repeated treatment to be assessed. Water samples were collected after each step and analyzed by SGS Analytics in Sweden according to SS-EN ISO 17294-2:2023.

The analysis by SGS Analytics was performed using ICP-MS (inductively coupled plasma -- mass spectrometry). This method involves introducing the water sample into a high-temperature plasma (approximately 8,000 C), which ionizes the elements. The ions are then separated and quantified using a mass spectrometer. ICP-MS is highly sensitive and capable of detecting trace element concentrations at the microgram-per-litre level. The following elements were analyzed: aluminum (Al), antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni), selenium (Se), uranium (U) and vanadium (V).

Mr. Ainsworth has not verified any of the information regarding any of the properties or projects referred to herein other than the Viken property. Mineralization on any other property referred to herein is not necessarily indicative of mineralization on the Viken property.

About District Metals Corp.

District Metals is led by industry professionals with a record of success in the mining industry. The company's mandate is to seek out, explore and develop prospective mineral properties through a disciplined science-based approach to create shareholder value and benefit other stakeholders. District is a 2025 TSX Venture 50 company, ranking among the top-performing issuers on the TSX Venture Exchange in the past year.

District is a uranium polymetallic exploration and development company focused on its flagship Viken property in Sweden. The Viken property covers 100 per cent of the Viken energy metals deposit, which contains the largest undeveloped mineral resource estimate of uranium in the world, along with significant mineral resource estimates of vanadium, molybdenum, nickel, copper, zinc, and other important and critical raw materials.

For further information on the Viken property, please see the technical report entitled "NI 43-101 Updated Mineral Resource Estimate and Technical Report on the Viken Energy Metals Project, Jamtland County, Sweden," dated effective April 25, 2025, which is available on SEDAR+.

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