you don't have to give the metal they mine an exact name, you could use some kind of general reference to it, such as mercury is sometimes reffered to as quick silver, iron pyrites as fools gold and so forth.
i believe they also reffered to mithril as true silver in something. not certain if it's LoTR or one of the games inspired by it, but, you could always say that the metal they're mining is high quality iron that they turn into their own blend of steel. thus you have dwarven steel, that's always known to be 'higher quality' than other races in every other game it's in.
as for the demons, you could always use existing demon names from whatever folk lore - celtic or norse ones maybe, to be slightly different from the vast arrays of hebrew esque names that you get in some games, from random name generators.
as for ADOM though, i believe they called them hurthlings, and you could get hurthling cakes. a typical one was sweet. a blessed one was sickly sweet and a cursed one was real hurthling (what the trolls loved.)
i used to like ADOM, but i seem to suck at rogue likes, as the only ones i've ever completed are ToME, using a possessor deathmold in the watcher of the waters body or some such, and some other random ones that are less note worthy.
oh, one thought that i did have though is, golems. would the dwaves be able to make some such thing as them, and give you some kind of parts customisation option so you could have say, a number of custom made golems guarding your miners to take the brunt of any unleashed horrors while you bring your guards to take them down?
eh. maybe not, i just like the idea of being able to craft additional support when you can spare the resources.