Gilsonite can be used in foundry sands as a carbon additive instead of sea coal, which is the conventional item for this application.
The key factor for using Gilsonite as foundry sand additives is the high lustrous carbon content, which also includes a good amount of fixed carbon within. The key matter is adding a secondary layer of graphite while the layer made from Gilsonite carbon prevents the generation of Carbon Monoxide to the Graphite Layer. This procedure is called creating a reductive atmosphere.
While lustrous carbon content, as an important factor in high value metal foundry, provides a better finish for molding, the gas generation provided by the Gilsonite is 3 times more than sea coal. This results an upgraded mold release.
Despite all the advantages, the usage of Gilsonite as a foundry sand additive is decreasing. The reason of this decline is the high price of Gilsonite added to drop of sea coal price in the past years, which caused with the low oil prices, a heavy drop of sales for American Gilsonite Foundry Grade (also GPA Grade) in Europe. Currently the new origins and resources of Gilsonite are merging on this market, such as Iranian Gilsonite. Their usage in China & India for foundry sands has been tested successfully. However, the steady market requires more extensive research and greater marketing yet to be done by Iran Gilsonite Suppliers.
– Book of “Applied Science of Casting Metals”
– Book of “The Chemistry and Technology of Petroleum”