Assuming the likely approval by OZ Minerals Ltd (ASX: OZL) shareholders to sell most of the company's mining assets and discoveries to China's Minmetals group, the new OZ Minerals will be much leaner machine, with just one mining asset - the Prominent Hill copper-gold mine in South Australia.

The company said today that the current board of eight would be reduced to possibly three - all likely to be new faces - senior executives will be reduced from eight to five, and about 80% of staff would go. Many of the departing people will gain jobs with Minmetals.

Chief executive Andrew Michelmore would stand down and become a senior executive of Minmetals, and director Ronnie Beevor would not seek re-election while Anthony Larkin resigned yesterday.

Other directors Peter Mansell and chairman Barry Cusack indicated they would not seek re-election.

The quest to find a new managing director has begun.

Meanwhile, OZ Minerals' general manager for project and technical services, John Nitschke, told this week's South Australian Resources & Energy Investment Conference that the new Prominent Hill mine was achieving desired performance.

He, said the processing plant at the mine, in South Australia's north, was routinely achieving desired performance.

The processing plant is running constantly at around 1,050 tonnes per hour throughput, we are achieving head grades averaging 1.55% copper and 0.5 grams per tonne gold, and are now focused on getting metal recoveries up to the target rate of 88%, said Nitschke.

There are many indications that the overall processing operation could well go beyond its design capacity as long as we can keep the ore feed up to it.

Nitschke said the new mine has injected $A470 million ($US348 M) into Adelaide's economy and $A25 M ($US18.5 M) into regional South Australia.

The highest grade portion of the Prominent Hill ore body is now exposed in the bottom of the open pit.