Hematite. Major iron compounds. The basic materials used for the manufacture of pig iron are iron ore, coke, and limestone. As such, its chemical formula is simply itself. Iron is hard, brittle, fairly fusible, and is used to produce other alloys, including steel. Pig iron from a blast furnace contains several impurities, one of which is phosphorus. 74.2. In general, the pig iron is an intermediate product of the iron industry.Pig iron, known also as crude iron, is produced by the blast furnace process and contains up to 4–5% carbon, with small amounts of other impurities like sulfur, magnesium, phosphorus, and manganese.Pig iron is supplied in a variety of ingot sizes and weights, ranging from 3 kg up to more than 50 kg. The iron in the processed ores must be dissolved out by chemical processes. Direct reduced iron (DRI), also called sponge iron, is produced from the direct reduction of iron ore (in the form of lumps, pellets, or fines) to iron by a reducing gas or elemental carbon produced from natural gas or coal.Many ores are suitable for direct reduction. Formula % Fe. Wrought iron contains only a few tenths of a percent of carbon, is tough, malleable, less fusible, and usually has a "fibrous" structure. Pig-Iron Production from Microsoft Encarta. Iron is itself an element. 48.2. Magnetite. Its elemental symbol is Fe, for ferrous. Fe 3 O 4. Combustion process. Geothite / Limonite. Siderite. Name. Fe 2 O 3. The oxygen in the ore oxidizes the phosphorus by the reaction 12 P + 10 Fe 2 O 3 → 3 P 4 O 10 + 20 Fe . The coke is burned as a fuel to heat the furnace; as it burns, the coke gives off carbon monoxide, which combines with the iron oxides in the ore, reducing them to metallic iron. Metallic iron is most commonly produced from the smelting of iron ore to produce pig iron. Additional iron ore, Fe 2 O 3 , is included with pig iron in making steel. HFeO 2 ~ 63. FeCO 3. Carbon steel is an alloy of iron with small amounts of Mn, S, P, and Si. 69.9. This requires an element that binds oxygen more strongly than iron.