The approvals were made on 19 December, just before Australia shuts down for the Christmas break.
The three mines are already so large that they would almost cover greater Sydney, or most Australian cities.
"Today's approval is yet another example of the Australian Government deciding to create more climate change rather than less. Another time that Minister Plibersek was on the side of coal companies, not the environment," said Rod Campbell, Research Director at The Australia Institute.
"Putting this out just before Christmas is a classic 'taking out the trash' tactic. While Australians are trying to enjoy the end of the year, the Minister is doing the bidding of multinational coal companies.
"With every heatwave and every bushfire this summer, Australians should remember that their government is making this problem worse, not better."
