BHP billiton's northern Escondida copper mine produced 327,863 tons of copper in the first half of this year, according to the company. The mine is the world's largest copper mine.
The output of copper concentrate in the first half of the Escondida copper mine was 237,891 tons, down 35.7% year on year. Cathode copper output was 89,972 tons, a decrease of 47.1% year on year.
The decline in production was mainly affected by the strike. In the first quarter, a labor union strike disrupted output by 40 days.
But the latest data show that output has recovered quickly since the strike ended in late march, with output jumping to 230,760 tonnes in the second quarter from 97,103 tonnes in the first quarter.
The strike ended without a pay agreement, which means new consultations will be held in the coming months.
The drop in output from the strike has reduced corporate profits by 91 percent to $50 million in the first half of the year, although the average copper price rose 22 percent to $2.61 a pound.