How do you separate iron from stainless steel?

Answer 1

More info would have been helpful, but:

Hydrochloric acid. It'll bubble on contact with iron, and eventually dissolve it, allowing you to identify which is which or simply remove the iron.

"Stainless Steel" is steel in which most or all of the carbon has been removed.

An easily available commercial product is called Tap-out.

Answer 2

Iron and stainless steel are both ferromagnetic materials, but stainless steel contains chromium and nickel that reduce its magnetic properties. To separate iron from stainless steel, you can use a magnetic separator to pull out the ferrous iron while leaving the non-magnetic stainless steel behind. Alternatively, you can try heating the mixture to a high temperature and then using a magnet to attract the iron.