PERTH (miningweekly.com) – Mining giant Rio Tinto on Tuesday warned that its current round of staff culling could last longer than anticipated, as the miner worked to lower its costs.

Speaking on the sidelines of the Global Iron and Steel Forecast conference, in Perth, Rio Tinto iron-ore chief Andrew Harding said that the company was “consulting strongly” with its staff about how the redundancies would be handled.

“Our aim is to do that as quickly as possible,” he said.

While Harding gave no firm numbers on how many jobs could face the axe, he said that Rio was looking at a number in the hundreds. Local media reports are citing a number of 800 job losses in the Pilbara.

“I run the business on trying to make it the most valuable lowest cost business in the marketplace - it ensures its health and longevity. That is the target. The changes we make include everything from supply contract and equipment use and availability improvements, and the number of employees that we need are outcomes and not targets,” he added.

Speaking to delegates at the Global Iron and Steel Forecast, Harding said that Rio’s aim was to maintain its standing as the lowest-cost producer of high-grade iron-ore.

The miner was in the midst of increasing its iron-ore capacity to 360-million tonnes a year, and was expected to produce some 330-million tonnes of iron-ore during the full year, upping that to 350-million tonnes by 2017.

“On a 100% basis, we are expecting the full expansion from 220-million tonnes a year to be delivered at an industry-leading capital intensity of between $110/t to $120/t,” Harding said.

The additional volume would be provided from a number of very low-cost brownfield options, with about 40-million tonnes already approved and being implemented, with an average mine production capital of around $9/t.

This included additional tonnage from the West Angelas, Nammuldi and Brockman mines. Further brownfield tonnage would also be added from the Yanicoogina and Paraburdoo operations.

However, Harding pointed out that Rio had recently deferred the investment decision on the proposed 20-million-tonne-a-year Silvergrass mine until next year.

“The reasons for this are characteristic of Rio Tinto –  it improves our present cash position, and enables us to study and push for lower overall development costs, well below original estimates.”

In 2014, Rio’s cash cost for its Pilbara operations was recorded at some $17/t.