How to separate aluminum and steel apart?

Well Amit you idiot. use a magnet, but i wish i found that out earlier, now im £2000 in debt and wonga.com wont let me have a loan beacause im not 'reliable' im disgusted by you, I love it how your the big man, the go to guy. with your 'beautiful' profie picture. Now my wife has left me and I had to sell the kids they were everything to me, Thanks a bunch mate.

or you can use a magnet :)

 

The Question is tricky? Aluminum and Steel are to be separated physically, the best way to use a resistance furnace, at700C as Aluminum melting point is less, it can be easily separate.
Where as if you want to remove Al from steel melt i.e.
chemical separation of two, then use an oxidising agent as Aluminum is strong deoxidiser.
Al present in melt will tend to react with the added oxides to form Al2O3 which can be skimmed in form of slag.
As Im considering steel as melt you can use mill scale as oxidising agent to tackel aluminum.