Gilsonite as a Carbon Source in Metallurgy

September 16, 2026 · 1 min read · Sun Gilsonite Technical Team

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Gilsonite as a Carbon Source in Metallurgy – Close-up of gilsonite ore pieces

Gilsonite contains high carbon and low ash, making it a possible carbon source in some metallurgical processes.

Considerations

Volatile matter is high, so fixed carbon is lower than calcined products
Sulfur content should be checked

What carbon raisers do

Carbon raisers (recarburizers) increase the carbon content of molten iron or steel. The most common are calcined petroleum coke, graphite and anthracite.

Multi-wall kraft bags of asphaltic mud additive – additives application

Can gilsonite be used?

Gilsonite has high total carbon but also high volatile matter (55–75 %), so its fixed carbon is lower than calcined products. The volatiles burn off as smoke and gas when added to hot metal. For this reason it is not a typical recarburizer, but it can be useful where a reducing atmosphere or gas generation is wanted, as in foundry sand.

Comparison

Material	Fixed carbon	Volatile matter
Calcined petroleum coke	very high	very low
Graphite	very high	very low
Gilsonite	moderate	high

Recommendation

Use calcined products for recarburizing and gilsonite for green sand. See foundry grade gilsonite.

See gilsonite lump.

Recommended product

Data sheet

Gilsonite Lump

Data sheet – Gilsonite Lump
Property	Typical value	Test method
Appearance	Black, shiny lumps	Visual
Size	0 – 50 mm (custom)	Sieve
Softening point (R&B)	150 – 220 °C	ASTM D36
Ash content, max	5 – 10 %	ASTM D3174
Moisture, max	1 %	ASTM D95
Volatile matter	55 – 75 %	ASTM D3175
Solubility in toluene, min	95 %	ASTM D2042
Specific gravity @ 25°C	1.04 – 1.10	ASTM D70
Typical dosage	Depends on application.
Packing	1 MT jumbo bags or bulk; 20 MT per 20ft container.