Rautamalmi

Rautamalmi is Finnish for iron ore, meaning rocks and minerals from which iron can be economically extracted. Iron ore deposits occur in a range of geological settings and host minerals such as hematite (Fe2O3), magnetite (Fe3O4), siderite (FeCO3), goethite and limonite. Ore quality is usually described by iron content; hematite and magnetite ores commonly contain 50% or more Fe, while some lower-grade deposits may be processed through beneficiation.

Formation: Iron ore bodies develop through sedimentary processes, magmatic differentiation, or hydrothermal activity. Banding and layering are characteristic of banded iron formations formed in ancient oceans; laterite and saprolite deposits form through tropical weathering; magnetite and skarn deposits form in contact zones with igneous intrusions.

Mining and processing: Ore is extracted by open-pit or underground mines. After processing, ore is crushed, milled and concentrated by magnetic separation (for magnetite), gravity separation, flotation, or other methods. Concentrates are often pelletized or sintered for use in steelmaking.

Economic importance: Iron ore is the principal raw material for steel production and constitutes one of the most traded minerals worldwide. Global mining activity is concentrated in several large ore provinces, with major producers including Australia, Brazil, China, and other regions. Environmental and social considerations include land use, tailings management and water protection.

Terminology: In Finnish geology, raudamalmi refers to iron ore deposits as a broader category of iron-bearing rocks and concentrations suitable for extraction.