Description
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Lutetium is a lanthanide that is a silvery white color in its natural state. It is resistant to corrosion and has the highest melting point of all the lanthanides. Lutetium has an atomic weight of 174.967, a melting point of 3006 °F, and a boiling point of 6156 °F. Lutetium is extremely expensive and so it is not used frequently on a commercial basis; one use of lutetium is as a catalyst for petroleum cracking in refineries, it is also used to date meteorites.
Isolation
Lutetium is never found in nature in its free state, but it occurs in minerals which also contain other lanthanides and rare earth metals.
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The isolation procedures that are used to extract lutetium from the minerals it occurs in are very complex and difficult. The difficulties of these extraction and isolation procedures make small scale laboratory isolation of lutetium impossible. Lutetium is found, in addition to other rare earth metals and lanthanides, in the mineral monazite.
The isolation process of lutetium begins with treating the monazite with sulfuric acid, hydrochloric acid, and sodium hydroxide. This beginning process helps to extract the lanthanides, including lutetium, from the monazite in their salt form. Further extraction processes using repeated solvent extractions and ion exchange chromatography are needed to reduce lutetium from its salt form. Once lutetium is reduced to its fluoride compound, it is further isolated with treatments with pure metal calcium. In this reaction, the lutetium fluoride is combined with metal calcium and heated; any calcium contaminants that are left are removed through vacuum processes to yield pure lutetium.