If you check some of the economic uses of Alumina and Aluminium Ores, they include;
- Usage as spark-plug insulators,
- for integrated-circuit packages,
- for bone and dental implants
- laboratory ware,
- sandpaper grits and grinding wheels etc.

Not trying to undermine the usefulness and importance of Alumina to Russia, but at the moment, it seems they can carry on, and can be able to survive without Australia's alumina. The Australian government's sanctions may also have been instigated by the United States in a bid to increase the sanctions Putin and Russia have already incurred. I can't say for sure how this sanction can slow and force the hand of putin to abandon the invasion, but Australia's complaince with sanctions against Russia shows that they are no supporters of Putin's actions.