See the Orange Cloth thread as this uses the same technique.
Instructions
• Two characters/clients required, (A) and (B).
• (B) should have mining skill.
• (A) needs Mugg the Miner's Quest* for ore.
• (A) needs to be on an Ethereal Mount** and have 125 items in pack including a pile of ore (as much as you can hold) not marked as quest item.
• (A) puts the unmarked ore on the floor.
• (B) double-clicks the ore to bring up target cursor - LEAVE CURSOR THERE.
• (A) picks up ore, puts in pack and marks as quest item. (A) then dismounts from Ethereal Mount.
• (A) should now have 126 items in pack, so picks up the pile of quest-flagged ore and releases it in pack - it will fall to the floor due to item carry limit.
• (B) now uses the target cursor on forge, creating fire ingots!
* Mugg the Miner is found South of New Haven, around 98o S 153o E.
** If you don't have an Ethy or Charger of the Fallen, you can instead use a craft menu once you're at 125 items including the ore. Craft anything, and while it is being made, pick up the ore. When the crafted item appears in pack, release the ore and it will fall to the ground the same way as above.
Note:
It seems you cannot craft anything with these ingots (while retaining the hue) as the game doesn't recognise them as iron or any other type of ingots. I know someone who is claiming to have crafted something with them but I have not seen it so he may be making it up.