Resource Upgrade Raises Stakes for Diatreme’s Long-Life Silica Sand Mine

Significant Resource Upgrade

Diatreme Resources Limited (ASX, DRX) has unveiled a major Mineral Resource Estimate (MRE) upgrade for its Northern Silica Project’s Si2 Deposit in North Queensland. The Measured Mineral Resource has surged by 278%, from 49.5 million tonnes to 187.5 million tonnes, while total tonnage increased by 16% to 272.5 million tonnes. Since 2021, the total MRE has grown by an impressive 513%, underscoring the deposit’s expanding scale and quality.

This substantial upgrade confirms Si2 as one of Australia’s most significant undeveloped high-grade silica sand deposits, boasting an average purity exceeding 99% SiO2. Such high purity is particularly sought after for photovoltaic glass production, a critical component in solar energy technologies.

Strategic Location and Market Potential

Located within the Cape Bedford–Cape Flattery Dune Field and adjacent to the Port of Cape Flattery, the Si2 Deposit enjoys logistical advantages that enhance its commercial appeal. The proximity to port facilities supports efficient export capabilities, positioning Diatreme to tap into the growing global demand for premium silica sands, especially in renewable energy sectors.

Diatreme’s CEO, Neil McIntyre, highlighted the project’s potential, stating that the upgrade “reinforces the outstanding potential” of the Northern Silica Project. He emphasized the company’s focus on establishing a long-life mining operation tailored to photovoltaic silica markets, with permitting and testwork advancing alongside the planned Pre-Feasibility Study (PFS).

Pathway to Development

The updated MRE provides a robust geological foundation for the upcoming PFS, which will explore mine scheduling and design optimized for a 25-year life of mine. Production targets are set between 3 to 5 million tonnes per annum, reflecting a significant scale of operation.

Environmental permitting remains a priority, with detailed impact and mitigation assessments underway as part of the Environmental Impact Statement (EIS), expected for submission in the third quarter of 2025. Concurrent metallurgical testwork aims to refine product specifications and confirm suitability for photovoltaic and other industrial applications.

Following successful testwork, Diatreme plans to initiate binding offtake discussions with global end-users, signaling a move towards commercialisation. The project’s designation as a Major Project by the Federal Government further underscores its strategic importance and potential economic impact.

Technical Rigor and Confidence

The MRE upgrade is underpinned by extensive drilling campaigns, including vacuum, aircore, and hand auger methods, totaling nearly 500 drill holes. The resource classification adheres to the JORC Code (2012), with a significant portion now classified as Measured, reflecting high confidence in geological continuity and grade consistency.

Bulk density testing and metallurgical assessments confirm the deposit’s amenability to conventional processing techniques, such as washing and screening, to produce low-iron, high-purity silica sands. The geological model accounts for dune morphology and groundwater levels, ensuring accurate tonnage and grade estimations.

Broader Portfolio and Strategic Partnerships

Diatreme’s Northern Silica Project is part of a broader silica sands portfolio in Far North Queensland, including the Galalar and Cape Flattery projects. The company benefits from a strategic partnership with global materials group Sibelco, which has invested approximately $49 million into the projects and Diatreme at the corporate level.

With a strong focus on environmental, social, and governance (ESG) principles, Diatreme is engaging closely with local communities and stakeholders to ensure sustainable development. The company’s experienced management team is well-positioned to advance the project through exploration, development, and financing stages.