Nex Metals Explorations (ASX:NME) reports metallurgical testwork has increased gold recovery at its Kookynie Tailings Project from 52% to 71% through carbon-in-leach (CIL) processing and light grinding.
The bulk samples were collected from tailings dump four at the Cosmopolitan Mine in April 2026 adjacent to historical drill collar locations from October 2017.
Two 50kg bulk samples returned gold head grades of 0.94 grams per tonne (g/t) gold (Au) and 0.96g/t Au, consistent with historical drilling and confirming the test work represents the broader tailings inventory.
Testwork identified two processing modifications that increased gold recovery by 19 percentage points, representing relatively 37% more gold recovered than initial direct cyanidation testing.
NME says replacing conventional direct cyanidation with a CIL process increased overall gold recovery from 52% to 59% using unground tailings. Lightly grinding the sample to P80 106 micrometres prior to CIL processing further increased recovery to 71%.
Managing Director Ken Allen says the results represent an important milestone in the technical development of the project.
“Through a disciplined and methodical metallurgical test work program, we have demonstrated a clear pathway to materially improve gold recovery using a relatively simple processing route,” Allen says.
“Increasing overall gold recovery from 52% to 71% is a meaningful outcome in its own right. More importantly, these improvements have been achieved through conventional processing techniques that provide a solid foundation for the next phase of process validation.”
The company also identified tungsten as a potential by-product, returning a head grade of 0.063% tungsten trioxide.
Gravity concentration confirmed scheelite reports to the gravity concentrate, which supports further evaluation of a secondary tungsten product. NME notes no deleterious elements were identified above World Health Organisation guideline levels.
Allen says the next phase of metallurgical test work will focus on validating the proposed processing route and optimising recoveries.
Nex Metals Explorations is a gold producer with projects in Western Australia, including the Kookynie Tailings Project and a joint venture with the Wangkatja Tjungula Aboriginal Corporation for gold project development.
Write to Paula Fabe at Mining.com.au
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