Riversgold Ltd has confirmed strong gold recoveries exceeding 90% from oxide metallurgical testing at its Northern Zone Intrusive Hosted Gold Project, located 25 kilometres east of Kalgoorlie in Western Australia. The company also reported the final assay results from its recent reverse circulation (RC) and aircore (AC) drilling campaigns, which will inform the forthcoming maiden Mineral Resource Estimate (MRE).
Northern Zone Project Map showing proximity to the Kalgoorlie "Super Pit".
“Metallurgical testwork using cyanide bottle roll has closely replicated the original 2023 work previously reported when we were doing our due diligence on the Project,” chairman David Lenigas said. “Gold recovery results between 90.64% and 94.7% for five samples, that average 92.56% gold recovery, is an excellent outcome and bodes well for our plans to scope out potential starter pits for toll treatment (like nearby oxide pit operations such as BlackCat Syndicate's Myhree mine).
“We now have all the results back from the recent RC and aircore drilling programs which illustrate the main oxide mineralisation has the potential to link the west and east mineralised zones. The structural and geological modelling being undertaken by Xirlatem will add to the solid basis for the maiden MRE and will inform future drilling.”
Metallurgical testwork confirms strong recovery potential
Cyanide bottle roll tests conducted on five oxide samples from recent and historical drilling returned an average gold recovery of 92.56%. Testing in 2025 by Jinnings Laboratories on RC hole NZRC008 showed 93.67% and 90.64% recovery from a composite and its duplicate sample. These results mirror earlier work by Nagrom in 2023, which averaged 92.9% recovery across three samples. The consistently high recoveries validate the metallurgical quality of Northern Zone’s oxide mineralisation and support the viability of early-stage processing strategies.
Final drill results highlight shallow high-grade zones
The final 414 assays from the 32-hole, 1,805 metre drilling program included encouraging intercepts from both AC and RC holes. Notable results include:
- 6 metres at 6.12 grams per tonne (g/t) gold from 35 metres in hole NZRC012
- 10 metres at 8.89 g/t gold from 46 metres in hole NZAC127
- 3 metres at 8.20 g/t gold from 60 metres in hole NZRC016
A selection of the best RC and AC drill results from drilling this year are listed below:
Best 2025 RC and AC drill collar plan with gold grade contours from all drilling results to date.
AC drill collar plan and significant intercepts (White), with previously reported results (Grey), within gold grade contours from all drilling results to date. Last few remaining drill holes closed of mineralisation, and then NZAC144 and 145, have intersected a new mineralised zone.
While some holes have closed off mineralisation on the north-western boundary, new zones intersected by holes NZAC144 and NZAC145 warrant follow-up.
Exploration focus shifts to linking mineralised zones
Riversgold is now focused on connecting the western and eastern mineralised zones, where minimal historical drilling has taken place. The updated geological and structural modelling by Xirlatem will guide targeting and optimise future drill design. These efforts are expected to define a continuous mineralised corridor in support of the maiden MRE.
Development pathway supported by nearby projects
The company draws parallels with Black Cat Syndicate’s Myhree project, just 7 kilometres north, which has successfully employed a turnkey development and processing model. It also highlights similarities with Saturn Metals' Apollo Hill Project, where a Preliminary Economic Assessment has outlined a large-scale, low-grade heap leach operation.
Riversgold believes Northern Zone could support a similar development strategy, potentially on a larger scale.