Potassium ethyl xanthate
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Ball-and-stick model of the component ions of potassium ethyl xanthate | |
Names | |
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IUPAC name
potassium O-ethylcarbonodithioate
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Other names
potassium ethylxanthogenate
potassium-O-ethyl dithiocarbonate |
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Identifiers | |
140-89-6 | |
ChemSpider | 8491 |
Jmol 3D model | Interactive image |
PubChem | 2735045 |
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Properties | |
C3H5KOS2 | |
Molar mass | 160.29 g·mol−1 |
Appearance | Pale yellow powder |
Density | 1.263 g/cm3[1] |
Melting point | 225 to 226 °C (437 to 439 °F; 498 to 499 K) |
Boiling point | decomposes |
Acidity (pKa) | approximately 1.6 |
Vapor pressure | {{{value}}} |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references | |
Potassium ethyl xanthate is an organosulfur compound with the chemical formula CH3CH2OCS2K. It is a pale yellow powder that is used in the mining industry for the separation of ores. Unlike the related sodium ethyl xanthate, the potassium salt exists as an anhydrous salt.
Production and properties
Xanthate salts are prepared by the action of alcohols on carbon disulfide. The alkoxide is generated in situ from potassium hydroxide:[2]
- CH3CH2OH + CS2 + KOH → CH3CH2OCS2K + H2O
Potassium ethyl xanthate is a pale yellow powder that is relatively stable at high pH but rapidly hydrolyses at pH <9 at 25 °C. Unlike the sodium derivative, potassium xanthate crystallizes as the anhydrous salt and is nonhygroscopic.
Applications
Potassium ethyl xanthate is predominantly used in the mining industry as flotation agent for extraction of the ores of copper, nickel, and silver.[3] The method exploits the affinity of these "soft" metals for the organosulfur ligand. Potassium xanthate is a useful reagent for preparing xanthate esters from alkyl and aryl halides. The resulting xanthate estes are useful intermediates in organic synthesis.[4]
Safety
The LD50 is 683 mg/kg (oral, rats) for potassium ethyl xanthate.[3]
References
- ↑ Report 5 (1995) p. 5
- ↑ This report gives a detailed procedure Lua error in package.lua at line 80: module 'strict' not found.; Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Kathrin-Maria Roy "Xanthates" in Ullmann's Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a28 423
- ↑ One of several procedures using xanthate esters: Lua error in package.lua at line 80: module 'strict' not found.; Lua error in package.lua at line 80: module 'strict' not found.