Long ore grade intercepts were returned from a three-hole metallurgical drilling program at the Kalkaroo project in South Australia’s northeast, near the mining centre of Broken Hill.
The large 83-millimetre diameter PQ3 drill core will provide the required samples for additional metallurgical test work, which forms part of a pre-feasibility study (PFS).
Part of additional PFS work
Havilah CEO Walter Richards said, “Obtaining the fresh drill core metallurgical samples is a very important part of Havilah’s planned additional Kalkaroo PFS work.
“The drilling was well planned and executed and we obtained adequate quantities of good quality sample that we required.”
Large ore reserve
Kalkaroo hosts an ore reserve of 100.1 million tonnes grading 0.47% copper and 0.44 g/t gold along with cobalt.
Ongoing PFS work is being funded and managed by Havilah and follows previous study work sponsored by Wanbao Mining.
Hole locations were selected to be representative of the overall Kalkaroo deposit and in particular, of the four main styles of mineralisation.
As such, the results returned do not represent new mineralisation.
Oblique view of the Kalkaroo ore shells showing locations of the three new metallurgy holes.
All drill holes have been logged, photographed and sampled, with a quarter of the drill core sent for assay.
Long, continuous intervals
Long, continuous copper and gold mineralised intersections are typical of the Kalkaroo deposit
These are composite intersections that are comprised of more than one ore type.
READ: Havilah Resources better defines cobalt and copper prospects, potential to add to Mutooroo resource
The additional metallurgical testing program being undertaken by Havilah has three main objectives:
- Demonstrate improved gold recoveries in the saprolite gold cap;
- Demonstrate improved gold recoveries in the native copper zone; and
- Confirm the indicated cobalt, copper and gold grades in bulk pyrite concentrates.
Malachite representing secondary, supergene copper hosted by weathered and oxidised bedrock.
Richards said, “Establishing with certainty the best processing route to maximise gold recoveries is essential to confirming Kalkaroo’s project economics and supplementing the previously completed metallurgy work.”
Bulk pyrite samples to be prepared
With the excess sulphide samples generated by the current drilling, Havilah plans to prepare several bulk pyrite concentrate samples from the chalcocite ore and chalcopyrite ore, in order to confirm the levels of contained copper, cobalt, and gold.
In addition, these samples will provide suitable feed for future leaching and/or roasting studies to be conducted.
It is important to note that the grades of copper, cobalt and gold make this a potentially saleable direct shipping product.
“We are encouraged by the latent value of copper, cobalt and gold in the pyrite concentrate, which potentially can be recovered for very little additional expense,” Richards said.
“We intend to demonstrate this by obtaining larger samples of pyrite concentrate from bulk sulphide ore samples.
“This metallurgical work has the potential to add significant value to Kalkaroo over and above the already favourable economics,” he added.