Cast iron
Cast iron is made from pig iron, which is the product of smelting iron ore in a blast furnace. Cast iron can be made directly from the molten pig iron or by re-melting pig iron, often along with substantial quantities of iron, steel, limestone, carbon (coke) and taking various steps to remove undesirable contaminants. Phosphorus and sulfur may be burnt out of the molten iron, but this also burns out the carbon, which must be replaced. Depending on the application, carbon and silicon content are adjusted to the desired levels, which may be anywhere from 2–3.5% and 1–3%, respectively. If desired, other elements are then added to the melt before the final form is produced by casting.
Cast-iron cookware
Enameled cast iron is cast iron that has a vitreous enamel glaze applied to the surface. The fusion of the glaze with the cast iron prevents rusting, eliminates the need to season the metal, and allows more thorough cleaning. Enameled cast iron is excellent for slow cooking and drawing flavor from foods. Furthermore, pigments used in the enameling process can produce vibrant colors.