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
While enamel-coated cast iron doesn't have the seasoning and cleaning issues of bare cast iron, a similar style of enamel-coated cast iron can cost three or four times its bare cast iron counterpart. For those seeking to reduce iron in their diet, enameled cast iron limits the leaching of dietary iron into food. However, some of the benefits of bare cast iron, such as the ability to withstand searing heat and resist sticking, are lost through enameling. In addition, chipping of the enamel coating can occur if the pan is dropped, overheated, or cold water is added to a hot pot.