Description
⌕ Enlarge Image
Ytterbium is a lanthanide that is a silvery white color in its natural solid state. Ytterbium is very soft and can be dissolved in mineral acids; it also reacts slowly with water and oxidizes when exposed to air. Ytterbium has an atomic weight of 173.04, a melting point of 1515 °F, and a boiling point of 2185 °F. Some common uses of ytterbium include: as an alloy for dentistry uses, as a component in solar cells, and in isotope form for radiation sources.
Isolation
Ytterbium does not occur in its free state in nature, but it does occur in mineral compounds with other lanthanides. Isolation procedures are used to extract ytterbium from these sources.
⌕ Enlarge Image
Ytterbium is extracted on a commercial basis from such minerals as euxenite, monazite, and xenotime. These minerals also contain other rare earth elements or lanthanides that all share similar chemical characteristics with ytterbium. The similarity between the traits of these elements makes extraction and isolation of ytterbium highly complex; the complexity of the extraction process prevents ytterbium from being isolated on a small scale laboratory basis.
The first step of the ytterbium extraction process involves treating the minerals it occurs in with sulfuric acid, hydrochloric acid, and sodium hydroxide. These treatments extract the lanthanide from their mineral compounds in a salt form. Further processing of ytterbium salts using repeated solvent extractions and ion exchange chromatography result in a ytterbium chloride compound. Electrolysis is needed to isolate pure ytterbium from the chlorine. The electrolysis process uses a mixture of molten ytterbium chloride in addition to sodium chloride, and the procedure takes place in a graphite cell.