Using it the right way, it should be possible (even ones made with an arcanovi).
What does Koschbasalt?
Koschbasalt absorbs magic, so if you entomb a magic trap or at least cover the magic muzzle with a thick enough Koschbasalt wall, it should absorb the ignifaxius or whatever spell you want to fire.
But that means, you have to know that there a trap is, where the trap is and you have to cover it with Koschbasalt without triggering it.
But if you can do all that, I don't see why it shouldn't work.
But wearing a small rock of Koschbasalt wouldn't help.
Blaubasalt, the stronger concentrated essence of Koschbasalt, can absorb magic so strongly, that it can sometimes divert magic from its target to itself (I don't find the reference in my DSA books for that, but I'm sure that I've read it).
So wearing a rock of Blaubasalt could help (sometimes), but could also have it drawbacks. If you wear it, it could attract the ignifaxius, which should hit your partymember. And if it comes from behind and you have it on your breast, it could target the ignifaxius directly into your back. And the healing magic from your party mage also might not hit you ...