here you go, all of it and how to apply to your situation
https://www.ato.gov.au/General/Gen/Tax-treatment-of-crypto-currencies-in-Australia---specifically-bitcoin/declare assets and income with your tax return
tax is on profit only
Mining bitcoin
Where you are in the business of mining bitcoin, any income that you derive from the transfer of the mined bitcoin to a third party would be included in your assessable income. Any expenses incurred in respect to the mining activity would be allowed as a deduction. Losses you make from the mining activity may also be subject to the non-commercial loss provisions.
read carefully though for example: "Where you are in the business of mining bitcoin"
I do not know if this refers to a bitcoin mining business as well as personal bitcoin mining