Coal bag

The Coal bag is a reward purchasable from the rewards trader for 4,000 Dungeoneering tokens. It requires a Mining and Dungeoneering level of 35, however at least level 40 is needed to earn the tokens needed for coal bag. Only one coal bag may be in the player's possession at any time.

The coal bag holds up to 27 pieces of coal. When smelting or superheating, coal in the bag will be used before the coal in the inventory. It is refillable just like the rune essence pouch.

This item cannot be traded or dropped but it can be destroyed. Mined coal is not automatically stored into the bag. Instead, players must manually use a coal on the bag, just like potatoes with an empty sack. When coal in the player's inventory is used on it, all pieces of coal (up to 27) are deposited into the bag.

This item now has a right click ability while one is banking called "Fill" which takes all the coal in one's inventory and places it in the bag.

Uses
This sack provides an additional 27 coal slots and is useful for both mining and smithing as it allows players to increase coal ores carried per trip. It doubles the amount of bars per inventory you can have.

The first column identifies the type of bar to be made. The second indicates how many pieces of coal should be in each bag. The third represents how many of the primary ore (Iron, Mithril, Adamant, Runite) is required. The fourth column represents how many free inventory slots remain. The fifth column shows how many bars are produced. The last column indicates the experience received from smelting a full load (including coal in the coal bag) of that ore. It also never un-charges.

Blast Furnace (starting with an empty inventory)

Other Furnaces (starting with an empty inventory) Superheat Ores (start with nature runes and a fire staff equipped)

Trivia

 * Regardless of the amount of coal in the bag, it weighs 0 kg (even though 27 coals = 61 kg).
 * On 21 April 2010, the price of the Coal bag went from 20,000 tokens to 4,000.
 * Mod Chris L stated on the "Live Q&A New Skill - Answers" that the coal bag originally only meant to hold 10 coal "but when I went ingame to test it myself after making it, I realized it was a bit rubbish! I ended upon 27 as it meant you could smelt more runite ore per inventory, it worked out nicely".
 * Using an ore, instead of coal, on the bag will result in nothing happening, not even the message "Nothing interesting happens.", unless the bag is full, then it gives the message "Your coal bag is already full."
 * Adding coal to the bag doesn't stop your movement generally (walking, mining). There are some exceptions. First, you do not restart mining after the current loop (in which you add coal to the bag) of the mining animation has finished and you didn't manage to get the ore in that loop. Second, you stop moving if you clicked to climb a ladder and then add some coal to the bag.
 * Though the Coal bag is not tradeable, its value is shown when viewing "Items Kept on Death" as 25,000 coins. You can do this with all items earned from Dungeoneering.
 * Currently, if you are wearing Varrock Armour and the effect activates while smithing, the coal in your inventory will be used instead of the coal in the bag.

Coal bag