User blog comment:PopCultureNinja/Questions about Superman/@comment-16487016-20100423054149

1. Superman keeps Kryptonite around to study it... it is after all the last pieces of his homeworld. It's harmful to him, but that makes it more interesting and important to look into... and not every type of kryptonite kills him, a lot of them have different effects. he mostly keeps it around for scientific purposes though to my knowledge, and also, probably to keep it off the streets where it can do actual damage.

2. He crushes it into a fine powder and snorts it in small quantities.

3. He's only really hurt by direct exposure, so he has lead suits, and the rest of the time it's probably in a lead box or something.

4. Because a lead suit would be very difficult to move in, and his face would still be vulnerable... he wore legit armor at one point, but armor does not stand up well to super-level fights and invariably gets destroyed the next time he's in a fistfight with a galactic conqueror.

5. Superman would win, unless Voldemort completely got the drop on him. Superman has super-speed and heat vision, both of which are to my knowledge much faster than any spell-casting. He could also hypothetically search the world and destroy all horcruxes within minutes. However, if Voldemort blindsided Superman with an Avada Kedavra, he would totally murder the shit out of him.