Potassium ethyl xanthate (KEX) is an
organosulfur compound
Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulf ...
with the chemical formula CH
3CH
2OCS
2K. 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
A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achi ...
salt.
Production and properties
Xanthate salts are prepared by the action of
alkoxides on
carbon disulfide
Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical ...
. The alkoxide is often generated in situ from potassium hydroxide:
:EtOH + CS
2 + KOH → EtOCS
2K + H
2O
Potassium ethyl xanthate is a pale yellow powder that is stable at high pH but rapidly hydrolyses below pH <9:
:
Oxidation gives
diethyl dixanthogen disulfide:
:
KEX is a source of ethylxanthate
coordination complex
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...
es. For example have been prepared from KEX for M = Cr, In, Co.
Applications
Potassium ethyl xanthate is used in the mining industry as
flotation agent for extraction of the ores of copper, nickel, and silver.
[ 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 esters are useful intermediates in ]organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...
.[One of several procedures using xanthate esters: ]
Safety
The is 103 mg/kg (oral, rat
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...
s) for potassium ethyl xanthate.
References
{{reflist
Potassium compounds
Thiocarbonyl compounds
Metallurgical processes