Iron ore is an important raw material for steel production enterprises.
Different types of iron ore naturally have different characteristics. Now the following will illustrate several important iron ore:
1. Magnetite
It is a kind of iron oxide ore, whose main component is Fe3O4 that is a composite of Fe2O3 and FeO. It has a dark gray color and the specific gravity is about 5.15. It contains 72.4% Fe and 27.6% O. It is magnetic so the magnetic method always used in the separation process, which is very convenient to handle. But due to its fine structure, it is less reducible. After long-term weathering, it will become hematite.
2. Hematite
It is also a kind of iron oxide ore. The main ingredient is Fe2O3. It is dark red color. The specific gravity is about 5.26, and it contains 70% Fe and 30% O. Hematite is the most important iron ore. It can be divided into many categories by its own structural status, such as red hematite, specularite, mica iron ore, and clay hematite.
3. Limonite
This is an iron ore containing iron hydroxide. It is the collective name of two different structure ores of goethite HFeO2 and scale iron FeO. Some people also write the chemical formula of its main components as mFe2O3. nH2O. The ore is yellowish or brown, containing about 62% Fe, 27% O, 11% H2O, with the 3.6-4.0 specific gravity. Most of the limonite is attached to other iron ore.
4. Siderite
It is an ore containing ferrous carbonate, mainly composed of the FeCO3, which is in blue-gray color. The specific gravity is about 3.8. Most of this ore contains a considerable amount of calcium and magnesium salts. Since carbonates will absorb a lot of heat and release carbon dioxide at a high temperature of about 800-900°C, most of us roast this type of ore before adding it to a blast furnace.