Molten Iron
| Type | Crafted material |
| State | Molten |
| Transported by | Molten Channel |
| Stored in | None |
| Created in | Arc Furnace II Blast Furnace Blast Furnace II |
| Used in | Metal Caster Metal Caster II Oxygen Furnace Oxygen Furnace II |
Molten Iron is an intermediate molten product with can either be cast into Iron or further processed with the infusion of Oxygen to create Molten Steel in an Oxygen Furnace or Oxygen Furnace II.
In the very early game, Molten Iron is produced by smelting 
Iron Scrap recycled from the Abandoned Communications Station with Coal in a Blast Furnace. Once the Metal Scrap supply has been exhausted and Iron Ore is being mined, it is produced by smelting Iron Ore with Coal.
Upon unlocking the Blast Furnace II, Molten Iron can be made from Iron Ore Crushed at a higher efficiency with the added requirement of Limestone. At endgame, Molten Iron is generally produced using Graphite in place of Coal and with the addition of Water to reduce the amount of Exhaust byproducts produced.
