Slag

A glass-like byproduct that is created when smelting ore. Crushed Slag is often used in the production of Concrete.

Notes

Slag is a glass-like byproduct created when smelting ore at a kiln or smelter. As a waste product, it stacks and must be stored or disposed of, but it is also a valuable ingredient: crushing it produces crushed slag used in concrete manufacturing. Stockpiling slag for later processing into crushed slag is a practical way to turn industrial waste into high-tier building materials.

Notes are AI-generated and may be imprecise.

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Recipe (12 ways to make this)Blast Furnace · Advanced Smelting Lv 1Blast Furnace · Smelting Lv 1Blast Furnace · Smelting Lv 1Bloomery · Smelting Lv 1Bloomery · Smelting Lv 1Blast Furnace · Advanced Smelting Lv 1Blast Furnace · Recycling Lv 2Blast Furnace · Recycling Lv 2Blast Furnace · Recycling Lv 2Blast Furnace · Recycling Lv 3Blast Furnace · Smelting Lv 4Bloomery · Smelting Lv 4

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Upgrade modules (one per slot)

Basic (none)Basic Upgrade (−10% cost · −5% labor · −25% time)Advanced (none)Advanced Upgrade (−10% cost · −10% labor · −35% time)Modern (none)Modern Upgrade (−15% cost · −10% labor · −50% time)Specialty (none)Advanced Smelting Upgrade (−5% cost · −25% time)

Advanced Smelting level 0Skill level changes labor only.

Talents

Carbon Enrichment (Advanced Smelting Lv 3) Metallurgy Improvements (Advanced Smelting Lv 3) Rolling Steel (Advanced Smelting Lv 6) Steel Processing (Advanced Smelting Lv 6) Fuel Efficiency (Smelting Lv 6) Using Bellows (Smelting Lv 6)

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Quantity to craftScales ingredients, labor, time, output & total raw by the number of crafts.

Ingredients

Ingredients for this recipe

Ingredient	Qty	Type
Iron Concentrate	1	item
Ceramic Mold	1	item
Quicklime	4	item
Charcoal	8	item

Byproducts (garbage)

Garbage byproducts of this recipe

Material	Qty / craft
Wood Scrap	1.28
Ceramic Scrap	1.03
Crushed Mixed Rock	0.19

Crafting waste collects in the station's garbage output and must be hauled away or recycled — see the Garbage & Recycling guide.

Crafting

Crafting stats

Labor	60 calories
Craft time	1.5 min
Throughput	≈ 160 Steel Bar / hour (base)

As a block

Hardness 4 is the minimum pickaxe tier that can mine this block.

Cost shown for a Modern Pickaxe at Mining level 0. Set your level / talents in the ⚙ Character panel to recompute. ≈ estimate.

Total raw to craft this

Recompute for my setup

• 40× Limestone
• 28× Wood (any)
• 15× Iron Ore
• 15× Quicklime
• 6.13× Clay
• 0.67× Steel Bar
• 0.38× Silica (any)

Approximate — category ingredients and any production cycles are counted as raw.

Categories

• Block
• Excavatable
• Ingredient
• Product
• Waste Product

Obtained from

• Charcoal Steel
• Copper Bar
• Gold Bar
• Iron Bar
• Recycled Copper Bar
• Recycled Gold Bar
• Recycled Iron Bar
• Recycled Steel Bar
• Steel Bar

• Smelt Copper
• Smelt Gold
• Smelt Iron

Used in

• Crushed Slag Lv3

• Crushed Slag Lv2

See also

TailingsWet Tailings

Each ingot leaves its glassy shadow — crushed, it becomes the foundation of concrete progress.