Ardea Resources Limited (ASX:ARL) has confirmed high-grade near surface nickel-cobalt mineralisation with diamond drill core drilling at the Highway nickel-cobalt deposit in Western Australia.
The company said results validate mineralisation models used in generating the Highway resource estimate. Highway is a key satellite plant feed source for the Kalgoorlie Nickel Project – Goongarrie Hub (KNP).
Intercepts at 0.5% Ni and 1% Ni cut-off grades include:
• AHID0002 42m at 0.77% nickel and 0.11% cobalt from 2m including 12m at 1.01% nickel and 0.22% cobalt from 16m and 6m at 1.00% nickel and 0.04% cobalt from 38m
• AHID0003 36m at 0.95% nickel and 0.08% cobalt from 2m including 24m at 1.11% nickel and 0.10% cobalt from 4m
• AHID0004 40m at 0.86% nickel and 0.10% cobalt from 10m including 28m at 0.96% nickel and 0.12% cobalt from 14m
• AHID0008 18m at 1.08% nickel and 0.06% cobalt from 4m including 14m at 1.21% nickel and 0.06% cobalt from 6m •
Ardea said there is consistently high cobalt grades, with significant intercepts:
• AHID0001 22m at 0.56% nickel and 0.47% cobalt from 38m including 2m at 1.17% nickel and 1.42% cobalt from 40m
• AHID0002 12m at 1.01% nickel and 0.22% cobalt from 16m
• AHID0004 12m at 0.80% nickel and 0.19% cobalt from 34m
The Highway metallurgical hole selection was primarily based on obtaining representative in situ material for testing an Atmospheric Leach hydrometallurgical flowsheet. In particular, high-magnesium nontronite-serpentine clay mineralisation was sought on the basis of its role in sulphuric acid demand and hence the KNP low-carbon flowsheet.
Managing Director, Andrew Penkethman, said Importantly, the programme generated drill-core test material specifically suited to High Pressure Acid Leach (HPAL), Atmospheric Leach (AL) and Mineralised Neutraliser for a low carbon flowsheet.
The company also advised that the Geological Survey of Western Australia have independently classified Ardea’s KNP as the largest nickel deposit in Western Australia.
“The core drilling at Highway was the first field test of the KNP low-carbon flowsheet model. It was important for confirming the expectation that high-magnesium mineralisation is suitable as an Atmospheric Leach (AL) feed and uniformly underlies the premium goethite High Pressure Acid Leach (HPAL) feed,” Mr Penkethman said.
“The 2021 Diamond Drilling (DD) programme supports Ardea’s modelling that Highway is particularly endowed with AL material. AL material is especially important to the low-carbon flowsheet as this helps enable the on-site acid plant to be expanded to generate excess steam which is used for off-grid power generation.
“The Highway DD programme tested well below the depth of historic RC drilling. In terms of Mineralised Neutraliser, from our detailed core logging, the neutraliser will be an extensive sheet below the AL feed at the base of conventional open pits.
“It appears to be of a cave-fill mineralisation style within saprock. In a production situation, this material would best be defined by grade control drilling from the base of pit floor and mined as ‘goodbye cuts’.
“With the Highway geological model now confirmed, we eagerly await the results of the ALS benchscale metallurgy, testing the Highway flowsheet model. These results will feed into ongoing DFS work flows and continue to enhance the KNP Goongarrie Hub as a globally significant source of sustainable and ethical minerals to fuel the battery revolution.”
For further information please visit: https://ardearesources.com.au/