Highlights

  • Column testwork achieved 95% gold recovery from paleochannel material at Mulgabbie North.
  • Metallurgical hole MNODH 022 returned 6m at 11.64 g/t Au, including 1m at 61.10 g/t Au.
  • Recovery exceeded 60% within 15 days and 90% within 65 days.
  • Cyanide consumption was about 0.26 kg/t, compared with a typical figure of around 0.5 kg/t.

OzAurum Resources Ltd (ASX:OZM) has reported heap leach column testwork results from its Mulgabbie North Gold Project, about 130km northeast of Kalgoorlie in Western Australia. The company said the results indicate the material is well suited to heap leaching, a lower-capital route than a carbon-in-leach plant.

Column Testwork Results

Column 3, using paleochannel material from metallurgical hole MNODH 022, recovered 95% of gold from a head grade of 2.58 g/t Au crushed to -12mm. Leaching was rapid, with more than 60% recovery in 15 days, more than 80% in 35 days and more than 90% in 65 days.

Columns covered three different ore types, all returning strong heap leach recoveries. Cyanide consumption was about 0.26 kg/t. The testwork was carried out by ALS Balcatta under the supervision of Kappes Cassiday & Associates Australia. OzAurum cautioned that laboratory results may not match recoveries at operating scale.

High-Grade Intercept and Resource Base

Hole MNODH 022 returned 6m at 11.64 g/t Au, including 1m at 61.10 g/t Au from 22m. Mineralisation sits within the Relief Shear, a corridor up to 50m wide extending about 8km within OzAurum's tenure, about 2km from Northern Star's Carosue Dam operation.

The Mineral Resource Estimate stands at 11.6Mt at 0.70 g/t Au for 260,000oz. Fresh material accounts for 184,000oz, or about 71% of resource ounces.

Development Strategy and Next Steps

CEO and Managing Director Andrew Pumphrey said the results demonstrate strong potential for a low-cost heap leach operation, with column testwork now covering all geological domains the company intends to process.

The results support a Stage 1 heap leach development and a possible Stage 2 expansion along the Relief Shear corridor. Future testwork will focus on fresh material, which could potentially be included in later stages if successful.

Key Takeaways

  • 95% recovery supports heap leaching as a low-capex development route.
  • Fast leach kinetics and low cyanide use are positive early indicators.
  • Fresh material, making up most resource ounces, is the next testwork focus.
  • Laboratory results still need to be confirmed at operating scale.