Fortescue has put first ore through its second ore processing facility at its Christmas Creek mine.
It comes only a week after the miner began running its second train unloader in Port Hedland.
According to Fortescue the second ore processing facility, constructed by Minerals Resources' subsidiary Crushing Services International, has only taken 14 months to complete.
"Once fully commissioned it will lift capacity of the mine to more than 50 mtpa and the combined output of Christmas Creek and the nearby Cloudbreak mine to 95 mtpa by the end of the year," Fortescue stated.
Mineral Resources said that construction of the plant, which began in September last year, is expected to reach full production capacity within three months.
It added that "the Christmas Creek circuit has been designed to handle and process a range of ore feed from the Chichester Ranges tenements including the wet, below the water table ore which requires specific scrubbing and de-sanding process components.
As part of the mine's expansion, it has also completed a number of additional infrastructure projects such as doubling the capacity of the operations village, building a remote crushing hub and 6.3 km overland conveyor, a new airstrip, and expanding its power plant.
The total workforce at the site is expected to be around 2300.
This latest development comes only days after it awarded Leighton a $1.5 billion mining contract for its operations at its Firetail development.