Diversified mining giant South32 wholly owns the Cannington mine...

Diversified mining giant South32 wholly owns the Cannington mine in North West Queensland – one of the world’s largest producers of silver and lead.

The mine has been in production for more than two decades and now produces about 6% of the world’s silver.

The 3Mtpa mining operation comprises an underground hard rock mine, a surface processing facility, a road-to-rail transfer facility and a concentrate handling and ship-loading facility at the Port of Townsville.

Silver, as well as zinc and lead, is extracted from the ore using grinding, sequential flotation and leaching techniques to produce high-grade lead and zinc concentrates with a high silver content.

Cannington’s is estimated to contain a total mineral resource of 55Mt at 184g/t silver from the underground sulphide and 30Mt at 98g/t silver from the open cut sulphide.

As at June 2019, its ore reserves totalled 21Mt at 173g/t silver with an estimated 12 years of mine life remaining.

During the September quarter, South32 reported 694,000t of ore mined including 2.97Moz of payable silver production. This silver output was higher than the last two reporting periods but less than the September 2018 quarter’s 3.18Moz silver production.

The company’s silver production guidance for the full 2020 financial year is 11.2Moz.

In 2018, South32 also completed the acquisition of Arizona Mining, adding the high-grade zinc, lead and silver Hermosa development option in Tucson, US to its portfolio.

In June 2019, the company declared a mineral resource for the Taylor deposit at Hermosa of 155Mt at 69g/t silver with a contained 344Moz of silver.

More than 70% of this resource is in the measured and indicated categories, which South32 said provided a “compelling base from which to advance the Hermosa project’s pre-feasibility study and target additional mineralisation”.

The company has been undertaking a drilling, resampling and relogging program and expects to conclude its pre-feasibility study before the end of the 2020 financial year.