1. make sure coal bag in inv.
2. take out 27 coal.
3. click coal bag to put coal into the bag.
4. take out 27 more coal.
5. put coal onto the belt. (click the belt then add all).
6. remove coal from coal bag. (right click, empty).
7. get 27 mithril.
8. put on belt.
9. wait for it to be ready from the bar dispenser. at first it will look empty in the middle, then it will go orange, then grey.