| Potassium ethyl xanthate | |
|---|---|
|
potassium O-ethylcarbonodithioate |
|
|
Other names
potassium ethylxanthogenate |
|
| Identifiers | |
| CAS number | 140-89-6 = |
| PubChem | 2735045 |
| ChemSpider | 8491 |
| Jmol-3D images | Image 1 |
|
|
|
|
| Properties | |
| Molecular formula | C3H5KOS2 |
| Molar mass | 160.3 g mol−1 |
| Appearance | Pale yellow powder |
| Density | 1.263 g/cm3[1] |
| Melting point |
225 – 226 °C |
| Boiling point |
decomposes |
| Acidity (pKa) | approximately 1.6 |
| Hazards | |
| R-phrases | R15 R21 R22 R29 R36 R38 |
| S-phrases | S3 S9 S35 S36 S37 S38 S39 S16 S23 S51 |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| 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.
Contents |
Xanthate saltss are prepared by the action of alcohols on carbon disulfide. The alkoxide is generated in situ from potassium hydroxide:[2]
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.
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]
Xanthates are poisonous because they release carbon disulfide. The LD50 is 683 mg/kg (oral, rats) for potassium ethyl xanthate.[3]