PERTH (miningweekly.com) – Major Rio Tinto has unveiled a maiden 503-million-tonne inferred mineral resource estimate at its Winu copper/gold project, in Western Australia, grading 0.45% copper.

The miner on Tuesday said that the resource estimate included a higher-grade component of some 188-million tonnes at 0.68% copper equivalent, and a cut-off grade of 0.45% copper equivalent.

Study work to date suggested that the copper mineralisation supports the development of a relatively shallow openpit mine, with Rio telling shareholders that first production from Winu has been targeted for 2023, subject to all necessary approval.

“We’re taking a more agile and innovative approach at Winu, and are working on the studies for a small-scale, startup operation focused on Winu’s higher-grade core as we take another step towards commercialising this deposit. We are also assessing options for future expansion in the Paterson region given the extent of mineralisation identified to date and our large land package,” Rio group executive of growth & innovation and health, safety & environment Stephen McIntosh said.

Rio on Tuesday also announced the discovery of a new zone of gold dominant mineralisation approximately 2 km east of the Winu deposit, at a prospect called Ngapakarra, as well as a number of other encouraging drilling results in close proximity to the maiden Winu resource, which provided further encouragement about the potential for the development of multiple ore bodies within one system, said McIntosh.

“The additional exploration results reported today support our view that there is potential to develop the Paterson region into a large-scale operation over time through both our 100% owned tenements and joint ventures. We’ve so far carried out exploration activity in just 2% of our tenements in the region and we’re building on this discovery at Winu with further encouraging results.”