PERTH (miningweekly.com) – A scoping study into the heap leach potential at the Whim Creek polymetallic project, in the Pilbara, has proven positive for junior Anax Metals.

The ASX-listed company said the heap leach study demonstrated the potential for low-cost production of copper cathode and zinc sulphate products, with the heap leach operation to run in parallel with the concentrator.

Anax earlier this year released a definitive feasibility study (DFS) into the Whim Creek project which estimated an initial mine life of eight years, based on the 4.6-million-tonne ore reserve, grading 1.36% copper, 2.30% zinc and 0.68% lead, supporting yearly production of 55 000 t/y of concentrate.

The DFS estimated that the project would require a capital investment of A$71-million and working capital of A$14-million, and estimated that Whim Creek would generate a free cash flow of A$340-million, and would have a pre-tax net present value (NPV) of A$224-million and an internal rate of return of 54%.

Anax said on Monday that the heap leach operation could see Whim Creek cashflows increase by up to 20%, to more than A$410-million, with the heap leach operation to deliver A$70-million in free cash.

Furthermore, by adding the heap leach operation, Whim Creek’s NPV would grow to A$270-milion with the project’s funding requirement only increasing to A$92.1-million.

The heap leach operation could also see Whim Creek’s production grow to around 10 000 t/y of copper and 10 000 t/y of zinc.

“The Anax team has developed world class bioleaching intellectual property that unlocks value for Whim Creek and provides a platform for our business to become the dominant player in consolidating Pilbara base metal projects,” said MD Geoff Laing.

“The capacity to treat primary ores and secondary/oxidised ores allows us to deliver treatment options for all the base metal projects in our region. We will produce a suite of battery metal products along with a key feedstock for the production of fertiliser through a facility that will generate low carbon emissions.”

The heap leach plant is expected to be installed in the second year of the Whim Creek operations, and will be funded from cashflows generated by the project.