BHP uses heap leaching to recover copper at operations in Chile, however, the technology has never really worked on Olympic Dam ores, which is why a different approach has been sought.

Heap leaching works by drip feeding acid through ore heaps to leach out all the metals.

Using heap leaching on ore stocks in SA could bring lower costs and alleviate water pressures on the drought-stricken state.

The trial began in 2012 on a small-scale heap leach facility in Wingfield under Bureau Veritas' supervision.

Bureau Veritas manager of major projects Clint Bowker said test work progressed from lab scale columns and bench tests to the world class testing facility in Wingfield, after seven years of research.

He said the facility would be available to the mining industry for further research and stay in care and maintenance mode for the future.

BHP general manager of Olympic Dam's surface processing Chris Barnesby said the promising results from the trial supported BHP's positive outlook for Olympic Dam, given the forecast demand increases for copper world-wide.

She said the trials produced 19 tonnes of copper.

"Most of which went back into the smelter and off to customers, though we kept a little to ourselves to commemorate the occasion," Barnesby said.