Iron ore occurs naturally in a variety of forms, from sand-like iron fines to solid rock masses. Crude ore, or ore mined in the natural state, seldom occurs in a pure state and requires some form of beneficiation.

Iron ores often contain impurities, undesirable chemical components such as phosphorous, sulfur, sodium, potassium (alkalis), alumina, silica and sometimes titanium. Other components such as calcium and manganese, may be considered desirable, depending on the composition of other raw materials used in the individual iron or steel producer’s process.
There are a variety of beneficiation methods that can be used to prepare iron ores, depending on the iron content in the ores. Some ores contain greater than 60 percent iron and require only crushing and blending to prepare them for further beneficiation. In other cases, operations including screening and concentrating are necessary to prepare the raw materials. Generally, the operations required before the iron ore is considered a finished product include:

• Crushing & Screening
• Grinding
• Concentration
• Agglomeration

Iron ores, coke, and limestone that will be sent to blast furnaces for ironmaking need to be permeable to allow for an adequate flow of gas through the system. Additionally, concentrates in crude ores that are very fine need to be agglomerated before they can be used as feedstock for the blast furnaces. The three major processes used for agglomeration include:

• Sintering
• Pelletizing
• Briquetting