Estelle Project Sees 68.7% Gold Recovery via Heap Leaching, Nova Reports

Metallurgical Advances at RPM Deposit

Nova Minerals Limited has unveiled promising metallurgical test results from its RPM Deposit, part of the Estelle Project in Alaska. The company’s recent test work demonstrates a remarkable 4.33 times upgrade in gold grade through advanced ore sorting technology, alongside heap leaching recoveries reaching 68.7% for lower-grade ore. These findings mark a pivotal step in refining the project’s processing strategy and enhancing its economic outlook.

The ore sorting test, conducted in partnership with Steinert Mining, employed X-Ray Transmission (XRT) and 3D laser technology to separate higher-grade gold ore from waste rock. A bulk test of 1,000 kilograms upgraded ore from 1.32 grams per tonne (g/t) gold to 5.72 g/t in a single pass. This selective pre-concentration reduces the volume of material requiring intensive processing, thereby lowering energy consumption and tailings production.

Heap Leaching Unlocks Value from Lower-Grade Ore

For ore below 2 g/t gold, which is rejected by the ore sorter, Nova Minerals is advancing heap leaching as a cost-effective recovery method. Heap leaching involves stacking crushed ore and irrigating it with a leaching solution to dissolve and extract gold. Test columns showed gold recoveries as high as 68.7% after 59 days, with reasonable reagent consumption. This approach allows the company to economically process material that might otherwise be considered waste, significantly increasing overall gold output.

Heap leaching is a proven technique used by major gold producers, including operations in Alaska, and offers lower capital and operating costs compared to conventional milling. By combining ore sorting and heap leaching, Nova aims to optimize resource utilization and reduce environmental impact.

Integrated Processing Flowsheet and Ongoing Optimization

Nova Minerals has proposed a high-level conceptual flowsheet integrating ore sorting, heap leaching, and carbon-in-pulp/carbon-in-leach (CIP/CIL) processing. High-grade ore (>2 g/t) will feed directly into the CIP/CIL circuit to maximize recovery, while lower-grade ore will be upgraded or heap leached accordingly. This multi-pronged strategy is designed to maximize gold recovery, improve capital efficiency, and lower processing costs.

Further test work is underway to refine the CIP/CIL process and to evaluate high pressure grinding rolls (HPGR) crushing technology, which could enhance power efficiency and reduce operational costs. Nova’s CEO Christopher Gerteisen highlighted the potential for this approach to position the Estelle Project as a low-cost, high-margin gold producer with a long mine life.

Strategic Implications for Estelle Project

These metallurgical advancements come as Nova Minerals continues its prefeasibility study, aiming to unlock the full value of the Estelle Project’s extensive mineral resources. The ability to upgrade ore grades significantly and recover gold efficiently from lower-grade material could materially improve project economics and accelerate development timelines.

With the Estelle Project located in the prolific Tintina Gold Belt, home to some of North America’s largest gold deposits, these results reinforce Nova’s ambition to deliver a major new gold mine in Alaska. The company’s ongoing work will be closely watched by investors seeking exposure to innovative processing technologies and scalable gold projects.