- For the Cataclysm item, see Hardened Elementium Bar.
Enchanted Elementium Bar is made by Miners with a skill level of 300 who have learned the Smelt Enchanted Elementium ability. Ten are required to construct [Thunderfury, Blessed Blade of the Windseeker], and are the objective of  Thunderaan the Windseeker.
The Smelt Enchanted Elementium ability is learned from the book [Goblin's Guide to Elementium], which drops from Master Elemental Shaper Krixix in Blackwing Lair. He is guarded by three Wyrmguards (powerful Drakonids) right before you fight Ebonroc and Flamegor. If you have one of the Bindings of the Windseeker, Earthcaller Franzahl will inform you on the ore and tell you where to find Krixix.
Previously learned by Mind Controlling Krixix, then having the controlling priest use the "Smelt Elementium" ability on his action bar on all miners (or non miners) in the raid who wished to learn it.