Based on what you have said, it sounds like it will be difficult for you to obtain a tourist visa to Canada.
To be approved for a tourist visa, you must show that you have strong ties to the country you are applying from and have no plans to stay in Canada long term. (Strong ties are typically: assets, land, property, business, family.) You will be applying from Australia and do not have strong ties to this country since you are only there on a study permit. So right away this will be a strike against you.
The fact that you have been refused for a student visa twice won't help and may cause CIC to suspect that you would like to remain in Canada long term.
However you can still try to apply and see what happens. Good luck.