If you are an Australian planning to move back to Australia to live with your non-Australian spouse or partner, be aware that your spouse/partner will need a spouse/partner visa, preferably organised BEFORE you make the move.
Due to current queuing and waiting times for spouse/partner visas, you really need to start preparations 9 to 12 months before your intended move date. Once you lodge the spouse/partner visa application, you need to reckon with 5 to 7 months before it is granted.
It's highly inadvisable for the non-Australian spouse/partner to enter Australia (intending to live there indefinitely) on just a tourist visa. You can apply for a spouse visa onshore before the three-month tourist status runs out, i.e. apply once in Australia, but it's considerably more expensive and the non-Australian spouse/partner won't be able to work until it comes through, which will be a number of months.
See: http://www.immi.gov.au/migrants/family/visa-options.htm
For help with Australian spouse/partner visa applications for Australians and their spouse/partners living in Belgium, I am an Australian-qualified lawyer in Brussels happy to lend a hand at no cost.