Potassium ethyl xanthate
Encyclopedia
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 ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

s. Unlike the related sodium ethyl xanthate
Sodium ethyl xanthate
Sodium ethyl xanthate is an organosulfur compound with the chemical formula CH3CH2OCS2Na. It is a pale yellow powder, which characteristically hydrolyzes to release malodorous products...

, the potassium salt exists as an anhydrous
Anhydrous
As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...

 salt.

Production and properties

Xanthate saltss are prepared by the action of alcohols on carbon disulfide. The alkoxide is generated in situ from potassium hydroxide:
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
Froth flotation
Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in several processing industries...

 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
Reagent
A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...

 for preparing xanthate esters from alkyl and aryl halides. The resulting xanthate estes are useful intermediates in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

.

Safety

Xanthates are poisonous because they release carbon disulfide. The LD50
LD50
In toxicology, the median lethal dose, LD50 , LC50 or LCt50 of a toxin, radiation, or pathogen is the dose required to kill half the members of a tested population after a specified test duration...

is 683 mg/kg (oral, rats) for potassium ethyl xanthate.
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