- Xanthate
Xanthates are the
salt s andester s of a xanthic acid, ROC(=S)SH or O-esters of dithiocarbonic acid where R is any organic residue. The ethyl ester CH3CH2OC(=S)SH is also the parent compound xanthic acid. Many xanthates have a yellow colour, which gives the compound its name derived from "xanthous", meaning yellow.IUPAC does not recommend the use of this term.Xanthates can be produced by the reaction of an
alcohol with sodium or potassium hydroxide andcarbon disulfide .Mainly worldwide used xanthates are:"SEX": Sodium Ethyl Xanthate
"SIPX": Sodium Isopropyl Xanthate
"SIBX": Sodium Isobutyl Xanthate
"PAX": Potassium Amyl XanthateCommercially available xanthates are from technical grade only and usually at a 90-95% purity. The content of inorganic by-products in the final product varies depending on the exposure to air and reaction parameters. Alkali-metal sulfide, sufate, trithiocarbonates, thiosulfate, sulfite or carbonate can be found. In addition, residual raw material such as alcohol and alkali hydroxide can exist. No general specifications for xanthates exist.
They can be obtained as powder, granules, flakes or sticks and are also available in solution. Main worldwide export are done from China under granules form.
Xanthates are used as flotation agents in mineral processing. They are intermediates in the
Chugaev elimination . Xanthates are also used to control radical polymerisation under the RAFT process, also termed MADIX (macromolecular design via interchange of xanthates).External links
* [http://www.iupac.org/goldbook/X06696.pdf IUPAC definition]
* [http://hazard.com/msds/tox/tf/q43/q123.html MSDS Potassium xanthate]
* [http://www.chemlink.com.au/xanthate.htm]
* [http://www.britannica.com/EBchecked/topic/650522/xanthate]
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