I think that this and even more so this link explain the issue quite well.

To clarify: I am looking for the first example of Dwarves (in RPGs, fantasy literature, or folklore) preferring axes as tools and weapons, and/or why this is the case (folklore, any information about mining, etc.) Side Note: Also, if anyone knows when the idea of dwarves with axes started, I'd be interested in that too. Is there an explanation in folklore, am I missing some key aspect of mining that requires axes, or is this just another case of ' Tolkien said something about it so it must be true'? It seems elves (what with living in forests) should be the ones with an affinity for axes, if anything.

The only use I can think of for axes in mining is to cut props for keeping mineshafts up, which would be done on the surface, so why would they take them with them? It doesn't seem to make any sense.

Inspired by this question and this question, why do dwarves use (battle)axes so much? They are meant to be miners and smiths traditionally, which explains hammers and picks, but why would they have a preference for axes?