The Australian government can afford to shake up to mining industry to a degree, because there aren't all that many countries the industry can go to instead. Australia happens to be the world's second largest producer of iron ore, for example (behind China), and happens to be geographically close to China, which Australian companies sell it to.
Brazil, the 3rd biggest producer only currently produces a bit more than half of what Australia does, and it costs more to ship it from China all the way from there. And if the industry left Australia for Brazil, they'd have to spend several years building up operations in Brazil.
According to the unions, the industry is fucking off to Russia, because they produce between one fifth and one quarter the amount Australia does.