Aeon Metals has stretched out the timing for its Walford Creek pre-feasibility study to allow further work focused on cobalt extraction.

The company said metallurgical and process workstreams were now well
advanced in the PFS for the North-West Queensland copper-cobalt project.

The front-end flowsheet design to produce copper, zinc and lead concentrates has proceeded well and is nearing completion.

But further work is needed on alternative back-end cobalt flowsheet routes to keep capital and operating costs down.

As a result of this additional metallurgical testwork and evaluation, completion of the PFS is now expected in the first quarter of 2021.

“We are confident that there are several potential process solutions available as part of the revised PFS process and we will be rapidly progressing these options over the next few months with a view
to completing the Walford Creek PFS as efficiently and effectively as possible,” managing director and chief executive officer Hamish Collins said.

The previously proposed back-end flowsheet design involved agitated bioleach to produce cobalt and nickel precipitate products.

Detailed evaluation indicated this route would require significantly more cooling capacity than envisaged in the Walford Creek Scoping Study – with consequent capital and operating cost impacts.

Aeon said it would now look into lower capital intensity bioleach options based on either heap leaching or vat leaching of cobalt-rich ore and/or a pyrite concentrate.

Aeon has also engaged a drilling contractor to commence Phase 1 of a new regional exploration program shortly.

This will focus on the large-scale Beauchamp (IOCG) target 100km west of Mount Isa and Sugarbag base metals target, described as having a similar setting to the Century and Kupferscheifer deposits.