The organisers of the Kalgoorlie conference released the preliminary program this morning, with Rio to present straight after international keynote Gene Sperling on the day one.

It is unclear who will be presenting for Rio, as the specific speakers won’t be announced until closer to the August forum.

Also returning to Diggers after several years is Newmont Asia Pacific.

Following Barrick Gold’s sell-off of its Australian assets, Newmont is currently Australia’s largest gold producer thanks to the Boddington and Tanami mines, as well as its 50% stake in Kalgoorlie’s Super Pit.

Other international companies to present will be South African gold miners AngloGold Ashanti and Gold Fields, both of which have major Western Australian presences.

Due to the slump in the iron ore price, Diggers stalwarts Atlas Iron, BC Iron and Mount Gibson Iron are absent from this year’s program.

However, Fortescue Metals Group will still present on Tuesday morning.

This year’s program is again dominated by gold, followed by nickel and zinc with a strong showing, with one or two presenters from copper, mineral sands, rare earths, tin and vanadium companies.

The organisers said the line-up was comprehensive snapshot of the participants in the Australian resources sector and demonstrated that there remained a substantial number of companies achieving positive outcomes with their projects.

All 135 booths in the marquee have been sold.

Diggers 2015 will be held at the Goldfields Arts Centre in Kalgoorlie from August 3 to 5.