Can I wipe a Galaxy S4 Mini with dead screen and digitizer?
Take the HardDrive Out Burn it

Also if Your google account is Connected:
1.Go to google.com Enter "Find My Phone
2.There should be a little Window with the last known location of your phone
3.There should also be 2 little buttons there a "Ring" and a "Recover"
4.Once you click on that all the way at the bottom there should be consider erasing your phone (The page where it should send you)
5.USe that and follow the instructions.
Good Lucj