Aluminium can (UBC) Recycling

Dear All,

While recycling the scrap aluminium should i use only one type of alloy series? For example scrap aluminum cans (UBC) is 3xxx series,so my final output metal also is 3xxx series aluminium alloy.

1) Is any problem if am mixing the scraps like 2xxx series alloy,3xxx series alloy,6xxx series alloys for melting.If this is possible then what is my final metal series?

2) If am not de-corated the cans what will happend during melting ?

Kindly advise me the above issues.