The Queensland government says the recent flooding stopped about 5% of the state's coking coal exports from getting to the global market.
Queensland accounts for 90% of Australia's steel-making coal exports.
The state government estimates 15 million tonnes of exports will be delayed or lost this year because of the floods.
But the ABC reports exports are expected to command a higher price in coming months as supply is slow to catch up with demand. The state government says it expects higher contract prices for coking coal in the June quarter.
Queensland was the state hardest hit by the floods. As a result its economic growth rate has been halved this year.
The state government said on Friday that it does not expect infrastructure to return to full capacity for "some time".