Rio Tinto PLC, one of the world's largest mining companies, on Thursday released its 2018 operating report.

Copper mine output in 2018 was 633,500 tons, up 33 percent from the previous year, the company said in a report.The mine is expected to produce 550-600,000 tons of copper in 2019 and 220-250,000 tons of refined copper in 2019.

For its Kennecott copper mine, the company said copper production rose 37 percent last year from a year earlier as mining activity continued in an open, high-grade copper region and production efficiency improved.

Rio said production of 50.4 million tons of bauxite in 2018 was down a modest 1 percent from the previous year and at the top of its guidance range.Strong production at Weipa's Gove and Andoom mines has offset sluggish production at two other mines.

The latest Amrun project will ship its first cargo six weeks ahead of schedule, with nine ships totaling 600,000 tons of bauxite to be shipped by the end of 2018.