Image Resources has expanded the Mineral Resource at its Durack mineral sands project by 43% to 37.7 million tonnes, while lifting contained heavy minerals and zircon content. The upgraded estimate gives the company a stronger technical base for an economic evaluation due later in 2026, although changes to the cut-off and mineral definitions complicate direct comparisons.
- Durack Mineral Resource rises 43% to 37.7Mt
- Contained in-situ heavy minerals increase 11% to 0.83Mt
- 95% of the resource is now Measured or Indicated
- Zircon rises to 17% of the heavy mineral assemblage
- Economic evaluation expected later in 2026
Durack Resource Expands to 37.7 Million Tonnes
Image Resources NL (ASX:IMA) has substantially enlarged the defined resource at its 100%-owned Durack mineral sands project in Western Australia, with total tonnes rising 43% to 37.7 million tonnes. The updated estimate contains 0.83 million tonnes of in-situ heavy minerals, an 11% increase on the previous estimate.
The bigger number comes with a marked improvement in confidence. Measured Resources account for 32Mt at 2.3% total heavy mineral, while a further 3.9Mt at 1.7% sits in the Indicated category. Together, Measured and Indicated Resources represent about 95% of the updated inventory, leaving 1.8Mt at 1.6% total heavy mineral classified as Inferred.
Zircon Content Rises After New QEMSCAN Analysis
The resource also has a more attractive reported mineral mix. Zircon now represents 17% of the heavy mineral assemblage, up from 14% in the earlier estimate. Image says the result is based on 25 larger composite samples analysed using QEMSCAN, replacing the previous assemblage work based on 13 smaller composites.
That comparison needs some care. The 2026 estimate uses a 1.2% total heavy mineral cut-off, versus 1.4% in 2018, changes the sand-size fractions used in parts of the model, applies revised titanium-mineral definitions and includes monazite for the first time. Image's own technical summary says total heavy mineral grade fell 23%, while contained heavy mineral tonnes rose 11%; zircon tonnes increased 35% and total titania mineral tonnes decreased 9%.
Drilling and Metallurgy Support Project Evaluation
The updated model draws on 630 vertical reverse-circulation air-core holes covering 8,420 metres, including 447 infill holes drilled by Image over 6,170 metres. The central deposit is now predominantly supported by drilling on a 40-metre by 200-metre spacing, which underpins the Measured classification.
Metallurgical work provides an additional technical input. An approximately 8.9-tonne bulk sample produced a 91.7% heavy mineral concentrate, with reported recoveries of 84.6% for heavy minerals, 99.8% for zirconium oxide and 95.3% for titanium dioxide in the five-stage spiral testwork. Those results come from laboratory-scale testing and do not establish commercial production economics, but Image says conventional equipment was sufficient to produce a saleable concentrate.
Economic Study and Tenure Milestones Ahead
Image says the new Mineral Resource will feed a comprehensive economic evaluation, with results expected later in 2026. The Durack deposit is about 300 kilometres north of Perth and shares geological and metallurgical characteristics with the company's Yandanooka deposit, roughly 24 kilometres to the north. Potential mining assumptions include an excavator feeding a mobile in-pit unit and bulk, non-selective mining.
The project still has important hurdles before a development case can be judged. Image has applied for Mining Lease M70/1456 over the northern portion of Durack and plans a further mining lease application over the south. The underlying exploration licence, E70/3762, is due to expire on 4 May 2027, with renewal or extension work also planned. Additional density sampling is intended to verify the formulas used to estimate tonnage, particularly in the central mineralised area.
Bottom Line?
The resource upgrade strengthens Durack's technical credentials, but the economic evaluation must show how much of the growth survives the lower cut-off, revised mineral classifications, processing assumptions and outstanding tenure work.
Questions in the middle?
- What project economics will the comprehensive evaluation produce once mining, processing and infrastructure assumptions are applied?
- How much of the reported resource growth reflects new drilling and how much reflects the lower cut-off and revised mineral definitions?
- Can Image complete the planned mining lease and exploration licence work before Durack reaches its key tenure deadlines?