40d:Refined coal

Refined coal and coal fuel are two in-game terms that refer to any unit of charcoal or coke, the two fuels used to power high-temperature industries, namely metalworking and glassworking. One unit of either of these fuels is required for every task at a conventional (non-magma) smelter, forge, kiln, or glass furnace. Magma versions of these facilities do not need fuel, and in fact cannot use conventional fuel to power them if their magma sources fail.

(Note that Bituminous coal is not a "refined coal" or "coal fuel", though it is directly related.)

"Fuel"

Though not seen in-game, the single word "fuel" is sometimes used informally in the forums and in various wiki articles in place of the in-game terms "refined coal" or "coal fuel". Since some understandable confusion can arise over the usage of the various terms "refined coal", "coal fuel", "charcoal" and "coke" (and also "bituminous coal", which is not a fuel), the simple umbrella term "fuel" will be used in the explanations in this article.

The two sub-types of fuel are charcoal and coke, and they are identical for in-game purposes, even if they come from different sources and have different in-game names. Whenever you see "coal fuel" or "refined coal", those refer to either charcoal or coke - they are interchangeable, and either one will serve the same purpose, as fuel for the desired activity.

Both charcoal and coke come in blocks, and are stockpiled in the Bars/Block stockpile under the "coal" entry. There is currently no way (nor need) to distinguish between the two when designating stockpiles.

At the risk of repetition, but to be perfectly clear - despite the different names, there is no distinction between charcoal and coke for any game activities. Both are "refined coal" or "coal fuel", or just "fuel".

Charcoal and coke are not fire-safe building materials.

In-game usage

At a conventional (non-magma) smelter, if you try to add a smelting task and have no fuel, you will see the message:

"Must have coal fuel"

You will not be allowed to add any tasks to any conventional smelter until you have at least one unit of either charcoal or coke.

If you have queued up several tasks and then run out of fuel, you will get an announcement similar to:

"Urist McFuelUser cancels job: Needs refined coal."

Note that a forge or glass furnace will let you add tasks if you have no fuel, and only once a dwarf arrives and finds they cannot complete that task will you get the announcement to that effect. You will get one announcement for each un-fueled task that is unable to be completed. Jobs are canceled when there is no fuel.

When you get either of these messages, you need more fuel - either charcoal or coke will serve equally well.

The two sub-types of fuel

There are 2 sub-types of conventional fuel - charcoal and coke. Charcoal and coke are identical in use - one unit of either one powers one activity at a conventional smelter, forge, kiln or glass furnace. The only difference is their source.

Wood does not burn hot enough to fuel these activities or facilities, and (in Dwarf Fortress) you cannot burn bituminous coal or lignite that has been mined and not refined in a smelter (altho' they are flammable).

Charcoal, from wood

Charcoal is created at a wood furnace using one wood log by a dwarf with the Wood Burning labour enabled. Skill levels in the Wood Burner skill are not required but reduce the time required for this activity.

• Required Building - Wood furnace
• Required Labour enabled - Wood burning
• Required Material - Wood

Coke, from bituminous coal or lignite

Coke is a type of refined coal, and is identical to charcoal for all game purposes. It is created at a smelter using one unit of fuel by a dwarf with the Furnace Operating labour enabled. Skill levels in the Furnace Operator skill are not required but reduce the time required for this activity.

Coke can be created from bituminous coal, producing 3 coke (net gain of 2 fuel), or lignite, producing 2 coke (net gain of 1 fuel). Magma smelters do not require conventional fuel for this process, and so the net yield for each is effectively +1 greater.

• Required Building - Smelter
• Required Labour enabled - Furnace operating
• Required Material - Bituminous coal or lignite

- plus one unit of fuel per unit smelted, if at a conventional smelter

Magma facilities

Magma replaces conventional fuel for magma smelters, magma forges, magma kilns and magma furnaces. No fuel is needed, nor can be used, for activities at these facilities. Note that you will still need charcoal or coke for smelting bars of pig iron and steel. (And see next section.)

Pig iron and steel production

Note that when smelting pig iron or steel at any location, one unit of either charcoal or coke is required in the reaction. Again, there is no distinction - both charcoal and coke serve equally well in the production of bars of either. That same one unit can simultaneously serve as the fuel for the activity at conventional (non-magma) smelters, so there is no savings at magma smelters in producing these two materials - one (and only one) charcoal or coke is consumed each time, either way. See those articles for more information.

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See Also:

• Smelting