... .Third party inspection acceptable Gaphitized petroleum coke for steel, foundry and casting Stable quality Carburizer for special steel, ductile iron High carbon, low sulphur ... carbon, low sulphur, low nitrogen, causing less slag in the furnace. The finished steel and iron have a better quality by using ... .5-5mm, 1-5mm, 3-8mm, ect. Graphitized Petroleum Coke for Steel, Foudry and Casting