There are multiple ways to obtain Flux. A few types of Stone (Limestone, Dolomite, Marble and Chalk) can be cooked into Lime, which can be subsequently made into Flux. These are known as Flux Stones. Seashells can also be cooked into Lime.
|Can be heated in:|
|Temp: Bright Red⋆⋆⋆⋆|
Ammonium Chloride Powder, which drops from breaking Salammoniac that generates around lava pools, can also be crafted directly in the crafting grid into Flux. Borax can be ground in a quern to make Flux.
|Borax||Ammonium Chloride Powder||Lime|
In order to process iron ore, the blast furnace requires an equal amount of flux for each individual ore piece to be thrown in at the same time.
|v1h||Limestone, dolomite, chalk and marble can be turned into flux. Recipe is hammer + cobble|
|v2 Build 7||Flux will now be used when welding|
|v2 Build 15||Fluxes should again use the correct rock types|
|v2 Build 17||Borax can now be used as a flux. It yields 6 flux.|
|v2 Build 26||Flux can now be processed from borax using a Stone Hammer, however the hammer will be lost in the process|
|77.6||The Blast furnace now properly only accepts ore at a 1:1 ratio with flux. It will no longer suck up any ore unless there is flux present as well.|
|77.10||Should be possible to place a stack of flux in an anvil now.|
|78.0||Fixed shift clicking of flux into an anvil to do the whole stack instead of just one.|
|82.0||Removed heated gypsum as a source of flux. The ability to do this was a bug.|
|83.0||Added ammonium chloride powder, which can be crafted into flux.|