Iron Ore

Iron is the fourth most abundant rock-forming element, producing hematite, magnetite, siderite, and geothite. Approximately 98% of the ore shipped in the world is consumed in the production of iron and steel. Iron oxides can come to the blast furnace plant in the form of raw ore, pellets, or sinter.

Iron ore that contains a lower iron content must be processed to increase its iron content. This ore is crushed and ground into a powder so the waste material called gangue can be removed. The remaining iron-rich powder is rolled into balls and fired in a furnace to produce strong, marble-sized pellets that contain 60% to 65% iron.

Sinter is produced from fine raw ore, small coke, sand-sized limestone, and numerous other steel plant waste materials that contain some iron. These fine materials are proportioned to obtain a desired product chemistry then mixed together. This raw material mix is then placed on a sintering strand, which is similar to a steel conveyor belt, where it is ignited by a gas-fired furnace and fused by the heat from the coke fines into larger size pieces that are from 0.5 to 2.0 inches. The iron ore, pellets, and sinter then become the liquid iron produced in the blast furnace.