According to Roy Hill's 2020 financial results the higher sales boosted cash flow 32% on the previous year to $3.7 billion.

The positive results came after the miner ramped up production to 60 million tonnes in the first half of 2020 with a wet high intensity magnetic separator plant.

Roy Hill also spent $400 million on other capital for the mine during the year, including a fourth crusher plant and conveyor system, which are under construction.

Roy Hill chairwoman Gina Rinehart said everyone at Roy Hill should be "very proud of what we have been able to achieve together".

"As we look forward, subject to securing government approvals, our growth plans will see us increase from 60Mtpa to 70Mtpa," she said.

"This along with continued capital investment and innovation projects, such as our wet high intensity plants and automation project are driving efficiencies across our mining operations, and will see us grow the 2800 jobs we already provide and continue to generate revenue in tax and royalties for the national and state governments."

Rinehart said mining was an industry to be proud of.

"It's an industry we shine in internationally, creating many opportunities, and helping to raise living standards," she said.

However, Rinehart cautioned that if Australia wanted to remain internationally competitive and grow its exports and revenue the government had to lower the "onerous, investment deterring burden" of red tape.