# Sponge iron

Pyanodons item · internal name `sponge-iron` · stack size 100 · first craftable in tier 7 (Production science pack, [tier 7](https://factorio.kalzumeus.com/tier/7.md))
HTML page: https://factorio.kalzumeus.com/item/sponge-iron/

## Produced by (2 recipes)

### Sponge iron (`sponge-iron`)

- 5 s · tier 7
- Ingredients: 10 × [Iron oxide](https://factorio.kalzumeus.com/item/iron-oxide.md), 2 × [Sodium sulfate](https://factorio.kalzumeus.com/item/sodium-sulfate.md), 100 × [Light oil](https://factorio.kalzumeus.com/fluid/light-oil.md), 100 × [Pressurized air](https://factorio.kalzumeus.com/fluid/pressured-air.md)
- Results: 1 × [Sponge iron](https://factorio.kalzumeus.com/item/sponge-iron.md), 400 × [Flue gas](https://factorio.kalzumeus.com/fluid/flue-gas.md)
- Made in: Direct reduction plant
- Unlocked by: [Steel - Stage 3](https://factorio.kalzumeus.com/tech/steel-mk03.md)

### Unslimed iron (`simik-iron`)

- 80 s · tier ?
- Ingredients: 4 × [Geothermal Water barrel](https://factorio.kalzumeus.com/item/geothermal-water-barrel.md), 50 × [Iron ore](https://factorio.kalzumeus.com/item/iron-ore.md), 1 × [Biosample](https://factorio.kalzumeus.com/item/bio-sample.md), 30 × [Pressurized air](https://factorio.kalzumeus.com/fluid/pressured-air.md)
- Results: 2 × [Sponge iron](https://factorio.kalzumeus.com/item/sponge-iron.md), 4 × [Unslimed iron](https://factorio.kalzumeus.com/item/unslimed-iron.md), 4 × [Hot air barrel](https://factorio.kalzumeus.com/item/hot-air-barrel.md)
- Made in: Simik den MK 01, Simik den MK 02, Simik den MK 03, Simik den MK 04
- Unlocked by an upgrade choice (script), not research

## Used in (1 recipes)

- Molten steel (`molten-steel-02`, tier 7) → [Molten steel](https://factorio.kalzumeus.com/fluid/molten-steel.md)