Physical Sand properties with Gilsonite resin are equal or superior to sea coal at significantly lower additive levels.

Gilsonite "Natural Asphalt" improves sand density, water requirements and strength (green, dry, baked, and hot). Gas evolution curves show that Gilsonite "Natural Bitumen" volatilizes more rapidly than sea coal. Gilsonite has the same total volatiles as sea coal at one-third the additive level.

Gilsonite Application
In Foundry

For high value iron castings, Gilsonite performs like no other. Its naturally superior properties mean high-quality castings with better finish and fewer imperfections. Foundries around the world have known for decades that when put to the fire of molten iron Gilsonite brings high performance to your foundry sand.

Gilsonite is combined with coal and other ingredients as an additive in foundry sands to insure the quality of the moulded part. The lower gas evolution should reduce ventilation load on the pouring floor. The physical property relationships developed in new sand mixes were confirmed by sand using Gilsonite as an additive. Casting finish of a Gilsonite mix has been equal to sea coal. Gilsonite is also used as a carbonated additive in casting sands that creates smoother plates on grey iron castings. In a lower temperature than coal, it makes the material volatile so that it improves the process of separating the metal from the mould. Moreover, the surface of the mould is smoother and cleaner.

Benefits of Gilsonite foundry sand

  • Reduces imperfections due to the rapid reaction between the silica sand mould and the oxidized surface of molten iron.
  • Improves sand peel from casting at shakeout.
  • Produce smoother, cleaner casting surface.
  • Minimise imperfections, casting losses, scrap.
Ratio of Gilsonite in Foundry

When the additive is combined with the clay, the nominal percentages by weight of the preened would be around 4% iron oxide, 4% Gilsonite and 16% metallurgical coke, the balance being essentially 70% to 75% clay and small amounts of other materials.

In the case of greater than normal amounts of smoke and/or emissions, the amount of the iron oxide can be increased in steps of 0.5% of the preened with a similar reduction in the metallurgical coke.

In the case of poor shakeout peel or casting surface problems the highly volatile carbonaceous material such as Gilsonite can be increased in 0.5% steps with a similar reduction in the clay portion of the preened. The permissible ranges of constituents beyond which the additive would be less effective, expressed as a percentage by weight of the preened, are 2%-6% iron oxide, 6%-2% Gilsonite, and 12%-18% metallurgical coke.