Editing 40d:Magma smelter

{{quality|Exceptional|15:12, 18 April 2011 (UTC)}}
{{Furnace|name=Magma smelter|key=l|job=[[Furnace operator]]
|construction=
* [[Magma-safe]] [[building material]] (non-[[economic]])
|construction_job=
* [[Architecture]]
* [[Masonry]] or [[Metalsmithing]]
|use=
* [[Metal]] [[ore]]
* Meltable metal item
|production=
* Metal [[bar|bars]]
}}{{av}}
The '''Magma Smelter''' is built and functions exactly like a normal [[Smelter]], but uses [[magma]] instead of [[fuel]]* as a heat source. Your map must have a [[magma vent]] that you have access to, and you must physically route the magma so it flows under the site of the magma smelter, or build the smelter over the existing magma.  

:''(* Note that [[coke]] or [[charcoal]] are still required in the production of [[pig iron]] and [[steel]], but as part of the reaction itself)'' 

A magma smelter is designated and built exactly like a conventional [[smelter]], needing only to be made of [[fire-safe|fire-safe materials]] (the construction screen says ''[[magma-safe]]'', but any fire-safe material will work).  

However, in order to operate, a magma smelter needs to be placed with at least one of the 8 outer tiles of the smelter one z-level directly above exposed [[magma]] of depth 4/7 or deeper, which requires that the floor at the respective tile to be removed or absent, for example by [[channel|channelling]].  There does not need to be magma present when the smelter is built, but the channel must be dug in advance, because this cannot be done after the building is already in place.  The game will not prevent you from mis-placing a magma smelter where it will not operate.  The magma channel can be under the impassable tile (top center of the 9), but it does not need to be. Placing it there may help prevent magma-dwelling creatures from actually seeing and attacking any dwarves that may be working in the smelter, and prevent the dwarves from seeing them, canceling any jobs and running in abject terror.

The circle on the top tile of the smelter will turn red when there is sufficient magma, or grey if there is insufficient magma.  
<gallery>
Image:functioning_magma_smelter.jpg|Working - red dot
Image:non_functioning_magma_smelter.jpg|Not Working - grey dot
</gallery>
If magma falls below 4/7 for even a moment, the magma smelter registers itself as having insufficient heat to work for that moment.  Even if the heat returns immediately, this cancels and removes any and all jobs, active or queued. This is common as sloshing magma first fills a tunnel beneath a magma smelter, as the smelter alternates between red and grey states while the magma fluctuates below 4/7 deep.  For this reason, either wait for the magma to reach a steady 4/7 or more before adding jobs, or consider using a magma-safe [[screw pump]] to quickly fill the channel to 7/7.

A magma smelter cannot use conventional [[fuel]] if the magma is too low or absent.

Magma smelters do not use up or cool down any magma when in use, nor do they require a fresh "flow" - any source will work, so long as the depth is maintained.  Magma does not currently obey pressure and seek its own level, so tapping a magma pipe from the lowest available Z-level will not cause all the magma above it to rush into the fortress through the opening in the smelter. 

Magma can be very [[fun]] to work with - do some reading, plan ahead, and get it right the first time.

It is not explained how it is that magma smelters are actually capable of working without refined coal, as real-life [http://en.wikipedia.org/wiki/Smelting smelting] generally cannot be done using heat alone, instead using the coke or charcoal as a chemical reducing agent as well as fuel.

{{Workshops}}