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
Cast iron fell out of favor in the 1960s and 1970s, as teflon-coated aluminum non-stick cookware was introduced and quickly became the item of choice in many kitchens. The decline in daily use of cast-iron cookware contributed to the closure of nearly all the iron cookware manufacturers in the United States. Many went out of business in the 1920s as seen in the List of cast-iron cookware manufacturers. Others were absorbed by other cookware manufacturers, such as the buyout of Griswold by Wagner in 1957, which was then purchased by the American Culinary Corporation. By the end of the 20th century, Lodge Manufacturing was the only remaining manufacturer of cast-iron cookware in the United States.