Last updated: February 11, 2026
Smelts 6 crushed ore into 1 ingot. Produces Slag if mixed ore types are used. Run at least 2 per ore type for adequate throughput.
Blast Furnace
The Blast Furnace is the first furnace unlocked in the game.
It requires 6 ores to produce 1 ingot. Normal ores do not yield more material than crushed ores, making crushing always beneficial before smelting.
Mixing different ore types in the furnace will result in Slag instead of an ingot.
All smelted products can also be reinserted into the furnace. They count as their corresponding ore type (for example, a Gold Ingot counts the same as Gold Ore when added).
Slag functions as Coal. However, adding directly will always produce Slag.
Specifications
- Production Speed: 20 items per minute (3 seconds per item)