General information

Yttrium [ʏtriʊm] is a chemical element with the element symbol Y and the ordinal number 39. It belongs to the transition metals and the rare earth metals, in the periodic table it is in the 5. Period as well as the 3. Subgroup (group 3) or scandium group. Yttrium is named after the first site, the Ytterby mine near Stockholm, as well as Ytterbium, Terbium and Erbium.
Yttrium (from Ytterby, mine near the Swedish capital Stockholm) was discovered by Johan Gadolin 1794 in Mineral Ytterbit. 1824 manufactured Friedrich Wöhler contaminated yttrium by reducing yttrium chloride with potassium. Only 1842 succeeded Carl Gustav Mosander separating the yttrium from the accompanying elements erbium and terbium.
Yttrium is not found in nature in the elemental state. Yttrium-containing minerals (Yttererden) are always associated with other rare earth metals. It can also be contained in uranium ores. Monazite sands with up to 3% yttrium and bastnasite with 0,2% yttrium are commercially degradable. Furthermore, it is the main constituent of xenotime (Y [PO4]).
Great Monazitvorkommen, the beginning of the 19. Discovered and exploited in Brazil and India in the 20th century, these two countries became major producers of yttrium ores. Only the opening of the Mountain Pass Mine in California, which produced large quantities of bastnasite until the 1990s, made the USA the main producer of yttrium, although the bastnasite mined there contains only a small amount of yttrium. Since the closure of this mine, China is 60%'s largest producer of rare earths. These are obtained in a mine near Bayan Kuang, whose ore contains xenotime, and from ion-absorbing clay minerals, which are mined mainly in southern China.

Recovery

The separation of the rare earths from each other is a laborious step in the production of yttrium. Fractional crystallization of saline solutions was the preferred method at the beginning, which was used early on for laboratory scale separation of the rare earths. Only the introduction of ion chromatography made it possible to separate the rare earths on an industrial scale.
The concentrated yttrium oxide is converted to fluoride. Subsequent reduction to metal occurs with calcium in the vacuum induction furnace.

Features

Yttrium is relatively stable in the air, but darkens under light. At temperatures above 400 ° C, fresh interfaces may ignite. Finely divided yttrium is relatively unstable. Yttrium has a low capture cross section for neutrons.
It is mostly trivalent in its compounds. However, there are also cluster compounds in which yttrium can assume oxidation states <3.
There are a total of 32 isotopes between 76Y and 108Y, as well as other 24 core isomers known. Of these, only one 89Y, of which natural yttrium exclusively exists, is stable. Yttrium is one of 22 pure elements. The most stable radioisotopes are 88Y with a half-life of 106,65 days and 91Y with a half-life of 58,51 days. All other isotopes have a half life under one day, with the exception of 87Y, which has a half-life of 79,8 hours, and 90Y with 64 hours. Yttrium isotopes are among the most common products of uranium fission in nuclear reactors and in nuclear explosions.

Usage

Metallic yttrium is used in tube reactor technology. An yttrium-cobalt alloy can be used as a permanent magnet. Yttrium is used as a material for heating wires in ion sources of mass spectrometers. In metallurgy, minor yttrium additives are used for grain refining, for example, in iron-chromium-aluminum heat conductor alloys, chromium, molybdenum, titanium, and zirconium alloys. In aluminum and magnesium alloys, it has a strengthening effect. Technically more important are the oxidic yttrium compounds:
Yttrium nitrate as a coating material in a mantle
Yttrium aluminum garnet (YAG) serves as a laser crystal
Yttrium iron garnet (YIG) as a microwave filter
Yttrium stabilized zirconia as solid electrolyte in fuel cells (SOFC, Solid Oxide Fuel Cell)
However, the most important uses of yttrium oxides and yttrium oxide sulfides are the versatility in trivalent europium (red) and thulium (blue) doped phosphors (phosphors) in television picture tubes, fluorescent lamps, and radar tubes.
Furthermore, yttrium ceramics and alloys are used in:
Lambda probes
Superconductors (eg yttrium-barium-copper oxide YBa2Cu3O7-x)
ODS alloys
spark
As a pure beta emitter 90Yttrium is used in nuclear medicine for therapy, for example, Radiosynoviorthese.
Yttrium is considered nonessential and toxic (MAK value = 5 mg / m3).

Please follow and like us: