Bloomery furnaces

Bloomery furnaces

The IME Bloomery Door is also called the high-temperature furnace. In the reference setup it processes iron-bearing muck: hematite, magnetite, limonite, and the compatible pyrite from Geology Additions. It is not the furnace for copper, tin, or other non-ferrous ores. For them look at the Smelting Furnace.

Construction rules

All three bloomery tiers use firebrick only. Ordinary clay brick, mudbrick, and refractory brick are not substitutes in this furnace family. A bloomery is also the only IME furnace that can damage its structure: each brick has a 5% chance to break after a firing. Keep spare firebricks and rebuild damaged positions before the next charge.

The Bloomery Door is a two-block door. Its recipe uses firebrick, iron nails or strips, and iron rods; use the in-game handbook for the exact quantities. Sneak-right-click the lower door to show the projection and sneak-right-click again to cycle tiers.

Tiers and block positions

The Muck fuel cells column means positions where the bloomery can hold its muck charge; it does not mean that every position is a dedicated charcoal slot. Fuel is calculated from the total muck layers.

Tier	Firebrick needed	Muckpile solts	Fuel required
1	39	1 x 4	1 fuel unit per 2 muck layers
2	69	4 x 4	1 fuel unit per 4 muck layers
3	99	9 x 5	1 fuel unit per 6 muck layers

Charcoal supplies one fuel unit. Coal coke supplies two. Add the muck first, then drop charcoal or coal coke as item entities onto a projected muck cell, preferably in the uppermost muck layer. The bloomery collects dropped fuel around its muck cells; do not place a charcoal pile as a block and do not put fuel in an explicitly empty or air position. The bloomery does not use smelt pots or flux.

Practical layouts

• Tier 1: A compact 3x3 shell with four charge/fuel positions around the two-block door.
• Tier 2: A 4x4 shell with a 2x2 muck column across four active layers (16 projected muck cells) and the door at the front. The uppermost 2x2 muck layer is a convenient place to drop the fuel.
• Tier 3: A 5x5 shell with the largest projected chamber and a 3x3 group of interior charge positions across the active layers.

Firing and output

1. Fill as many of the 16 projected Tier 2 muck cells as needed with iron-bearing muck. Each muck pile can hold up to 8 layers; do not fill the whole 4x4 interior or any projected empty space. Roasted fine iron gives the best availability.
2. For Tier 2, provide one fuel unit per four muck layers, rounded up. For example, 16 muck layers need 4 charcoal or 2 coal coke. A completely full charge of 128 layers needs 32 charcoal or 16 coal coke.
3. Drop the charcoal or coal coke onto a muck cell, rather than placing it as a charcoal pile. If the structure becomes invalid after loading, remove any placed fuel pile and check that the upper air spaces are empty.
4. Right-click the Bloomery Door with a torch without crouching to ignite it.
5. Wait for the firing to complete. Do not dismantle the structure while it is processing.
6. Break the finished Iron Mass with a pickaxe.

The reference output creates one Iron Bloom per 100 iron units, then returns the remaining eligible iron as nuggets. Continue with the normal Vintage Story iron and steel route after breaking the mass.

If the first iron is the only missing ingredient for the door, use the Sieve as an emergency bridge: ore muck in a sieve produces nuggets very inefficiently, but a few iron nuggets can unlock the first bloomery.