Anax’s plans to restart the Whim Creek copper project in Western Australia could see additional copper and zinc production following successful bioleaching tests.

Bacterial column leaching test work delivers between 79% and 80% copper extraction and over 90% zinc extraction from ore sorted “middlings”, which is material between clean mineral product and tailings that would ordinarily have been discarded.

Importantly for Anax Metals (ASX:ANX), the recently refurbished heap leach infrastructure at Whim Creek can be adapted to use its proprietary bioleaching technology at minimal CAPEX to deliver additional metal production.

The company is also developing its bioleaching intellectual property for application to other ores in the Pilbara region to further enhance outcomes from consolidation within the region.

Bioleaching test work is ongoing with larger column tests underway and optimisation of conditions to further improve both copper and zinc extraction.

“These results have exceeded our expectations and confirm that bioleaching of sorted sulphide ores using native cultures is highly effective,” managing director Geoff Laing.

“The company’s ore sorting and bioleaching IP ensures we have a significant strategic advantage for consolidation of the Pilbara base metal assets.

“Much of the existing Whim Creek heap leach infrastructure has been refurbished and permitting is in place to recommence heap leaching immediately. Adapting this infrastructure to bioleaching of sulphide ores requires minimal additional CAPEX which will significantly enhance metal extraction.”


Leveraging ore sorting

The successful bioleaching tests will allow the company to fully leverage its ore sorting flowsheet.

While ore sorting currently generates primary, high-grade pre-concentrates for flotation, it also produces secondary, lower grade “middlings” that are currently discarded.

Bioleaching enables the production of additional copper and zinc from the middlings, which is significant given that the recent Definitive Feasibility Study does not include revenue estimates for the bacterial leaching to recover copper and zinc or the potential revenue from aggregates left over from bioleaching.

A business case combining the DFS outcomes on the primary sort products and a scoping study on bioleached middlings ore is being prepared.



This article was developed in collaboration with Anax Metals, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.