Iron is my 'trash metal', I have so much of it similar to your silver problem. I finally started making a tower entirely out of iron. So far it houses 54 dwarves. All furniture is iron, all walls, etc. Everything. I might even give them iron clothing if you can do that.
“Too much” of any ore is not generally a problem; did you embark on Magnetite Mountain? You could continue with the Iron Tower but it’s been done and constructed walls/floors can't be engraved. If you come up with something novel that’s Wiki-worthy, that’d be good (either Stupid Dwarf Projects or a MegaProject,
http://dwarffortresswiki.Megaprojects.org/index.php/v0.34 ) It’s magma-safe so if you decide to bring the best thing about Dwarf Fortress up a hundred levels to your metalworks, you’ll need a lot of blocks, grates and pump parts.
Iron isn’t worth much, inherently or by use although The Iron Tower sounds pretty good and would certainly be something to talk about over drinks in the Tavern, probably over iron cups. Depending on which version you play, consider at least bringing it up to steel; much better edge on weapons, better hammers, better armor, no heavier, worth more as trade goods (esp. trap components), better for stud decorations. If low on flux stone, simply have some way for enough bones and one can still have a metals industry-based fortress since several animals breed quickly enough to base a metals industry. I’m partial to craigstooth boars: meat, leather, bones, tallow for soap, milk for cheese, teeth and sheared ivory for decorations and early, trainable meat shields for the military. I’m several years now into a Ye Olde Masterwork fortress so the steel becomes mithril, inherently valuable, useful for all kinds of things and pretty much absolutely necessary when Invaders are set at higher skill levels. Also prettier to look at and very dwarf-y. Maybe I’ll do Mithril MountainHome.