I have Schwalbe studs and they grip well on black ice.
Sounds daft, but you can cycle on a surface that it's difficult to walk on.
Be aware of stopping, you may be cycling OK, but your foot might slip when you try to ground it.
Studded tyres work on ice, but don't offer much more grip than an ordinary tyre on snow.
For that, you need something with studs/spikes and a chunky tread.
Studs can be used in all conditions.
If there's no ice, you pump them up a bit harder which tends to keep the studs away from the road surface.
They roll surprisingly well, although you will get a Rice Crispies sound as you bowl along which can lead to quizzical looks from pedestrians.