How do you separate aluminum and stainless steel?

There is a device called adata-couple which is comprised of an explosive bonded steel and aluminum strips or in the form of thi plates plates which allow for the connection of steel and aluminum by welding without fear of galvanic corrosion. Isolation can also be done using a nonconductor strip of say plastic like UHMW. If you are talking about separation of aluminum and stainless steel for waste services...keep in mind that stainless in not totally nonmagnetic It just has less carbon in the molecule