There is a dwarven weaponsmith in the Dwarven District of Stormwind who can craft with lightforge iron.  His name is Grimand Elmore.$B$BI've packed the iron you found into a crate.  Take it to Grimand and tell him your tale.  I'm sure he'll oblige someone on a quest such as yours, and craft for you a weapon - a weapon to give even Morbent Fel worry!