L10 - Iron and Manganese Flashcards
What are the uses of iron and manganese?
Used in blood cells, as industrial additives to steel for strength, and in medicines.
What is the enrichment to ore grade for iron and manganese?
Iron (Fe) is enriched 5x, and manganese (Mn) is enriched 220x
What are the atomic numbers and masses of iron and manganese?
- Iron (Fe): Atomic number 26, atomic mass 55.845.
- Manganese (Mn): Atomic number 25, atomic mass 54.938.
What are the melting points and densities of iron and manganese?
- Iron: Melting point 1538°C, density 7.87 g/cm³.
- Manganese: Melting point 1246°C, density 7.3 g/cm³.
How do iron and manganese compare in hardness?
Iron has a hardness of 4, while manganese has a hardness of 6.
What are the key ferrous and ferric iron minerals?
Ferrous (Fe²⁺): Siderite. Ferric (Fe³⁺): Hematite, chamosite, geothite, pyrite, limonite.
What are the key manganous and manganic manganese minerals?
Manganous (Mn²⁺): Rhodochrosite. Manganic (Mn³⁺/Mn²⁺): Braunite, kutnahorite, hausmannite
Which iron mineral is highly magnetic?
Magnetite
Which manganese mineral is commonly used in batteries?
Pyrolusite
What is the key redox chemistry for iron?
2Fe²⁺ + 3CO₂ ↔ Fe₂O₃ + 3CO
What is the key redox chemistry for manganese?
2Mn²⁺ + O₂ + 2H₂O ↔ 2Mn⁴⁺O₂ + 4H⁺
Where are the major reserves and production areas for iron?
- Production: Australia (38%), Brazil (17%).
- Reserves: Australia (30%), Brazil (18%), Russia (15%)
Where are the major reserves and production areas for manganese?
Production: South Africa (36%), Gabon (23%).
Reserves: South Africa (32%), Australia (26%).
What deposit types are common for both iron and manganese?
Marine chemical sediments, volcanic exhalations, hydrothermal veins, meteoric fluids/surface weathering.
What deposit types are exclusive to iron?
Magmatic and metamorphic fluids.
What is a key feature of banded iron formations?
Distinct banding and stratigraphy, formed around 2.7 billion years ago.
What are the depositional processes for iron?
Redox processes, oxygenic photosynthesis, and abiogenic oxidation.
What is a notable manganese deposit?
The Kalahari manganese field, with concentrations of 20–48% Mn and ore bodies up to 45m thick
What geophysical techniques are used in exploration for iron and manganese?
Magnetic surveys for magnetite and gravity surveys for dense ore minerals
What environmental issues arise from iron and manganese mining?
Acid mine drainage, asbestos exposure, and destruction of cultural sites (e.g., Rio Tinto blasts).
How is acid mine drainage formed from sulfidic iron ores?
4FeS₂ + 15O₂ + 8H₂O → 2Fe₂O₃ + 8SO₄²⁻ + 16H⁺.
What are the primary uses of iron and manganese?
Iron and manganese are primarily used in the steel and construction industries, as well as in batteries and the chemical industry.
What are the major deposit types for iron and manganese?
Marine chemical sediments, laterites, volcanic exhalations, hydrothermal veins, and skarns.
Why are Proterozoic iron and manganese formations significant?
They provide insights into the early atmosphere and the first oxygenation events
