what is the density of iron ore

Ferrous Mineral Aggregate Properties

Composition and Varieties

Naturally occurring rock formations containing iron compounds in sufficient quantity to be economically extracted. Common forms include:

  • Hematite (Fe₂O₃): The most abundant and significant source, exhibiting a reddish-brown to black color.
  • Magnetite (Fe₃O₄): Possesses strong magnetic properties and is typically black in color.
  • Goethite (FeO(OH)): A hydrated iron oxide, usually yellow-brown or dark brown.
  • Limonite (FeO(OH)·nH₂O): Another hydrated iron oxide, often amorphous and yellowish-brown. Technically a mixture of hydrated iron oxides, rather than a distinct mineral.
  • Siderite (FeCO₃): An iron carbonate mineral, typically light to dark brown.

Physical Characteristics of Iron-Bearing Rocks

These rocks exhibit a range of properties, influenced by mineralogical composition, porosity, and the presence of gangue minerals (undesirable components). Key properties include:

  • Hardness: Varies significantly depending on the specific mineral composition. Magnetite and hematite are typically harder than goethite and limonite.
  • Luster: Metallic to dull, dependent on the mineral and surface characteristics.
  • Streak: The color of the powdered mineral, a useful diagnostic tool. For example, hematite exhibits a characteristic reddish-brown streak.
  • Color: Variable based on the mineral type and impurities present.

Volumetric Mass Considerations

The measure of mass per unit volume is variable depending on the specific ore's mineral composition, degree of compaction, and the presence of impurities. The following are representative figures for pure mineral forms:

  • Hematite (Fe₂O₃): Approximately 5.26 g/cm³
  • Magnetite (Fe₃O₄): Approximately 5.18 g/cm³
  • Goethite (FeO(OH)): Approximately 3.3 to 4.3 g/cm³
  • Siderite (FeCO₃): Approximately 3.96 g/cm³

Note: Real-world samples will typically exhibit lower values due to porosity and the presence of other materials.

Factors Affecting Volumetric Mass

  • Porosity: The presence of voids within the material reduces the overall value.
  • Mineral Composition: Variations in the proportions of different iron-containing minerals directly impact the overall value.
  • Gangue Minerals: The presence of non-iron-bearing minerals (e.g., silica, clay minerals) lowers the aggregate value.
  • Moisture Content: The presence of water in pores or within the mineral structure (as in hydrated iron oxides) can influence the measured value.