Magnetite - Properties and Applications
Magnetite ore (Fe3O4) is a ferromagnetic mineral commonly used in magnetic separation coal washing processes.
Coal washing using magnetite is used to remove contamination from run-of-mine (ROM) coal, which usually contains rocks, middlings, used consumables and other contamination introduced by the mining process.
Magnetite ore is used in coal washing and recovered by magnetic separation for a number of reasons, including:
It has a RD greater than 4.9, and can be used to create stable suspensions from RD 1.30 to 1.80, which is the preferred operating range for the majority of coal beneficiation plants;
Its magnetic properties mean it can easily be recovered and re-used in the coal washing process;
Magnetite ore is relatively inexpensive when compared to other high-density materials used in dense media separation plants , such as ferrosilicon.
Magnetite ore is a ferromagnetic material, with the chemical formula Fe3O4, and is one of several types of iron oxide. It is a ubiquitous mineral in many parts of the world, including Australia, the USA, Canada, South Africa, Mozambique and many other countries across most of the world's continents.
Magnetite ore often occurs in metamorphic rocks, which formed from ferruginous sediments in both regional and contact metamorphic settings. It is commonly formed by the reduction of hematite and ferric hydroxide minerals in these rocks. Banded Precambrian iron formations commonly contain magnetite ore.