This is a little like Superman vs Flash- Black Bolt brings much more to the table, but what Iceman has can prove sufficient enough to win any way.
BB's scream would have no effect on Bobby (it would shatter him, but not to the point where he couldn't simply reform himself). If Black Bolt doesn't act quick, he could fall victim to the flash-freeze. But he could probably use his matter manipulation powers to pull a majority (maybe contain Iceman in a force-field).