Editing 40d:Refined coal

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:''(Disambiguation: In Dwarf Fortress, "coal" is not the same as [[bituminous coal]] - see that article if desired.)''

'''Refined coal''', '''coal fuel''', and just '''coal''' are three in-game terms that refer the same thing, 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. Refined coal is also needed as part of the pig iron and steel ''reactions'' (see below).

''(Note that [[Bituminous coal]] is '''not''' "refined coal", "coal fuel", or "coal", 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", "coal fuel" or just "coal".  Since some understandable confusion can arise over the usage of the various terms "'''refined coal'''", "'''coal fuel'''", "'''coal'''", "'''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" or "coal" in-game, those refer to ''either'' charcoal or coke - they are interchangeable, and either one will serve the same purpose, as fuel for the desired activity.  ([[Bituminous coal]] is not the same as "coal", and does ''not'' refer to fuel, but can be used to create fuel at a smelter.) 

Both charcoal and coke come in [[bar]]s, and are stockpiled in Bars/Block [[stockpile]]s if the "coal" entry is selected within the "Bars" section.  There is currently no way (or 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 "coal", or just "fuel". 

Charcoal and coke are ''not'' [[fire-safe]] building materials.

Bituminous coal [[block]]s and lignite blocks (sometimes offered by traders) can neither be used as fuel nor converted into fuel or back into stones in any way. They can only be used for building purposes and [[strange mood|moody]] dwarves may sometimes use them in artifacts and they can also be utilized for certain forms of [[bin#Thermonuclear_Reaction|fun]].

== 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:

<blockquote>"'''Must have coal fuel'''"</blockquote>

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:

<blockquote>"'''[[Urist|Urist McFuelUser]] cancels job: Needs refined coal.'''"</blockquote>

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.  

'''Coal''' is the generic term used in the [[stockpile]] menu.  It refers to a [[bar]] of either charcoal or coke.

To place bars of fuel in a stockpile, create a Bars/Blocks stockpile, or a [[Stockpile#Custom_stockpiles|custom stockpile]] with  {{k|e}}nabled and permit "coal" (found in the "Bars" sub-category).


== The two sub-types of fuel ==

There are 2 sub-types of conventional fuel - [[charcoal]] and [[coke]].  Charcoal and coke are identical in use - a single unit of either one powers one activity at a conventional smelter, forge, kiln or glass furnace, or can serve as the ingredient to make [[pig iron]] or [[steel]].  They are completely interchangeable, 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 raw [[bituminous coal]] or [[lignite]] (although they are flammable).

=== Charcoal, from wood===

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

::* Required Building - [[Wood furnace]]
::* Required Labor 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|Furnace Operating]] labor enabled. [[Skill|Skill levels]] in the [[Furnace operator|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]] or [[Magma smelter]]
::*Required Labor 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 smelter]]s, [[magma forge]]s, [[magma kiln]]s and [[magma glass furnace]]s.  No fuel is needed, nor can it 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 [[bar]]s 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 smelter]]s 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]]

[[Category:Physics]]
[[Category:Materials]]