Gilsonite foundry grade can increase carbon to make the iron softer
Gilsonite foundry sand help:
1. Reduce imperfections due to the rapid reaction between the silica sand mold and the oxidized surface of molten iron.
2. Improve sand peel from casting at shakeout.
3.Produce smoother, cleaner casting surface.
4. Minimise imperfections, casting losses, scrap.
Foundry gilsonite additives
During pouring, the gases given off from the gilsonite which is carbonaceous additives form a gaseous film which prevents the molten metal from making direct contact with the clay-coated sand grains, reducing sand-metal contact and consequently burn-on. When heated, the carbonaceous materials provide volatile, hydrocarbon gases which then pyrolize to deposit a lustrous carbon graphitic layer in the metal-mold interface region. This deposition acts as a physical barrier to iron silicate formation as well as not being readily wetted by molten iron. The combination effect is to inhibit burn-on and penetration. When the carbonaceous materials are heated they create a mold atmosphere of reducing gases. This atmosphere keeps the surface of molten iron at the interface free from oxidation, thus preventing formation of the iron silicate necessary for penetration and burn-on.
A. Burn-on: Sand grains firmly bonded to casting.
B. Burn-off: Casting surface has rough, sandy appearance.
C. Metal penetration: Metal penetrates into voids between sand grains forming fused mass of metal and sand, casting difficult to remove. D. Pin holes, caused by high nitrogen content.
Gilsonite foundry sand additive
Physical Sand properties with Gilsonite foundry are equal or superior to seacoal at significantly lower additive levels. Gilsonite foundry improves sand density, water requirements and strength (green, dry, baked, and hot). Gas evolution curves show that Gilsonite volatilizes more rapidly than seacoal. Gilsonite has the same total volatiles as seacoal at one-third the additive level.
Packing of foundry gilsonite
Gilsonite foundry grade is available in 50 lb. and 25 kilo net multi-ply paper bags which may be palletized and stretch wrapped. It is also available in bulk loaded trucks, containers, and a variety of bulk bag sizes.
Health and safety of Gilsonite
Gilsonite foundry is a naturally occurring hydrocarbon. There is no known history of dermatitis, lung disease or other health problems associated with handling of Gilsonite foundry as supplied. Dusts are subject to combustion. Normal precautions used with flammable materials apply.