Olympic Dam’s production capacity is back up after operations resumed for the primary Svedala Mill last week.
An electrical failure put the mill out of commission in January, taking nearly six months to complete repairs and commissioning.
Operations for the primary mill will ramp up in the coming weeks, with full production expected by the end of July.
BHP advised there would be a reduction in copper production as a result of the down time, between 60,000 and 70,000 tonnes, which may result in impairments this financial year.
Olympic Dam asset president Jacqui McGill offered her congratulations to the maintenance team responsible for bringing the mill back online.
"This week we reached the final milestone in the repair project and it is with sincere gratitude that I offer my thanks to the team and each and every employee at Olympic Dam who continue to contribute to our success," McGill said.
"The project has been a fantastic example of what Olympic Dam can achieve when we all work together."