Diatreme Resources has upgraded the Si2 deposit at its Northern Silica Project to 272.5 million tonnes with 99.21% SiO2. This confirms the scale and purity needed for premium PV glass markets. With permitting, testwork, and a PFS underway, Diatreme is progressing toward a long-life silica supply chain from Cape York.
Diatreme Resources, a prominent Australian mineral sands developer, has announced a significant mineral resource upgrade for its Si2 deposit, part of the Northern Silica Project in north Queensland. The latest resource estimate now places the Si2 deposit at 272.5 million tonnes, with an exceptionally high silicon dioxide (SiO2) content of 99.21% and minimal impurities. This development confirms the project's capacity to supply premium-grade silica sand for high-end applications, particularly in photovoltaic (PV) glass manufacturing.
CEO Neil McIntyre emphasized the importance of this milestone, stating, “This major resource upgrade reinforces the outstanding potential of our Northern Silica project. We have more than confirmed the scale and purity needed to support a long-life mining operation targeting PV silica markets.” The company views this resource confirmation as a foundational step in establishing a long-term, high-purity silica sand supply chain originating from Cape York.
The resource estimate includes a notable 278% increase in the measured resource category, which now accounts for 187.5 million tonnes. Overall, the upgrade represents a 16% increase from the previous total of 235 million tonnes. The revised estimate is based on a refined bulk density of 1.65 t/m³ and confirms a consistent particle size distribution. This uniformity is favorable for downstream processing into high-purity silica products, enhancing the deposit's attractiveness for industrial applications.
Strategically located within the renowned Cape Bedford–Cape Flattery dune field, and near the Port of Cape Flattery, the project enjoys logistical advantages due to its proximity to key export infrastructure and international markets. These factors bolster Diatreme’s ability to efficiently transport and supply high-grade silica sand to global customers.
Diatreme noted that this upgraded resource provides the geological confidence required to proceed with mine planning and supports the upcoming completion of a prefeasibility study (PFS). Simultaneously, the company is advancing its environmental permitting efforts, with comprehensive assessments ongoing ahead of the planned submission of the environmental impact statement (EIS) in Q3 2025.
Metallurgical testwork is also progressing to finalise product specifications, which will pave the way for initiating offtake discussions with potential customers in the high-purity silica sector. The Si2 deposit’s superior characteristics align with the growing demand for advanced silica materials used in solar energy and electronics manufacturing.
When combined with its additional silica holdings across the Cape Flattery and Cape Bedford regions, Diatreme’s total global resource now surpasses 500 million tonnes. This scale positions the company as a major contender in the rapidly expanding high-purity silica market, underlining its strategic role in supporting clean energy and advanced material supply chains.
