Chromium
| Chromium | |
|---|---|
| Cr | |
| In situ availability: | abundant |
| Necessity: | useful |
| Atomic number: | 24 |
| Atomic mass: | 51.9961 |
| group: | 6 |
| period: | 4 |
| normal phase: | Solid |
| series: | Transition Metals |
| density: | 7.15 g/cm3 |
| melting point: | 2180K, 1907°C, 3465°F |
| boiling point: | 2944K, 2671°C, 4840°F |
| N/A ← N/A → N/A | |
| V ← Cr → Mn | |
| Nb ← Mo → Tc | |
| Atomic radius (pm): | 140 |
| Bohr radius (pm): | 166 |
| Covalent radius (pm): | 127 |
| Van der Waals radius (pm): | |
| ionic radius (pm): | (+3) 62 |
| 1st ion potential (eV): | 6.77 |
| Electron Configuration | |
| 1s2 2s2 2p6 3s2 3p6 3d5 4s1 | |
| Electrons Per Shell | |
| 2, 8, 13, 1 | |
| Electronegativity: | 1.66 |
| Electron Affinity: | 0.67 |
| Oxidation states: | 6, 3, 2 |
| Magnetism: | Antiferromagnetic w/Spin Density Wave |
| Crystal structure: | Body centered cubic |
Chromium is a Transition Metal in group 6.
It has a Body centered cubic crystalline structure.
This element has 4 stable isotopes: 50, 52, 53, and 54.
"Chromium use in iron, steel, and nonferrous alloys enhances hardenability and resistance to corrosion and oxidation. The use of chromium to produce stainless steel and nonferrous alloys are two of its more important applications. Other applications are in alloy steel, plating of metals, pigments, leather processing, catalysts, surface treatments, and refractories." - USGS Chromium Statistics and Information[1]
Chromium on Luna would find many uses, not least of which is the creation of corrosion resistant alloys for industrial processes, as well as a strengthening agent in various alloys. Due to its high melting point, chromium is also a useful component in the construction of electric resistance heating elements[2].
The most important and abundant terrestrial ore of chromium is chromite. Geologic surveys of the moon have located vast deposits of chromite on the Sinus Aestuum, covering an area thousands of square kilometers in size[3]. It is believed that these deposits are located all across the moon, but are buried in deeper layers, and that the deposits on the Sinus Aestuum are the result of a meteorite impact blasting away the overburden.
Chromite could be reduced to an Iron-Chromium alloy using the FFC Cambridge Process, which could then be refined to pure Chromium, or could could be used directly for production of stainless steel or other iron alloys.
References
