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	{{chembox		{{chembox
			| Verifiedfields = changed
⚫	| verifiedrevid = 415428142
			| Watchedfields = changed
		⚫	| verifiedrevid = 422175173
	| Name = Sodium ethyl xanthate		| Name = Sodium ethyl xanthate
	| ImageFile = Sodium-ethylxanthate-2D-skeletal.png		| ImageFile = Sodium-ethylxanthate-2D-skeletal.png
	| ImageSize =		| ImageSize =
	| ImageName =		| ImageName =
			| ImageFile1 = Sodium ethyl xanthate 3D ball.png
			| ImageAlt1 = Ball-and-stick model of the component ions of sodium ethyl xanthate
	| IUPACName = sodium ''O''-ethylcarbonodithioate		| IUPACName = sodium ''O''-ethylcarbonodithioate
	| OtherNames = Sodium ethylxanthogenate<br/>		| OtherNames = Sodium ethylxanthogenate<br/>
	Sodium-''O''-ethyl dithiocarbonate		Sodium-''O''-ethyl dithiocarbonate<br/>SEX
	|Section1= {{Chembox Identifiers		|Section1={{Chembox Identifiers
	| CASNo = 140-90-9		| CASNo = 140-90-9
	| CASNo_Ref =		| CASNo_Ref = {{cascite|correct|??}}
	| CASOther =		| Abbreviations = SEX
			| UNII_Ref = {{fdacite|correct|FDA}}
⚫	| PubChem =
	| SMILES =		| UNII = 3R5A3652VK
	| InChI =		| EINECS = 205-440-9
			| SMILES = CCOC(=S).
			| InChI = 1S/C3H6OS2.Na/c1-2-4-3(5)6;/h2H2,1H3,(H,5,6);/q;+1/p-1
			| InChIKey = RZFBEFUNINJXRQ-UHFFFAOYSA-M
		⚫	| PubChem = 23690437
			| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
			| ChemSpiderID = 8493
	| MeSHName =		| MeSHName =
	}}		}}
	|Section2= {{Chembox Properties		|Section2={{Chembox Properties
	| C=3|H=5|O=1|S=2|Na=1		| C=3 | H=5 | O=1 | S=2 | Na=1
	| ExactMass =
	| Appearance = Pale yellow powder<ref name=r5p5>Report 5 (1995) p. 5</ref>		| Appearance = Pale yellow powder<ref name=r5p5>Report 5 (1995) p. 5</ref>
	| Density = 1.263 g/cm<sup>3</sup><ref name=r5p5/>		| Density = 1.263 g/cm<sup>3</sup><ref name=r5p5/>
			| MeltingPtC = 182 to 256
	| MeltingPt = 182–256 °C<ref name=r5p5/>		| MeltingPt_ref = <ref name=r5p5/>
	| BoilingPt = decomposes		| BoilingPt = decomposes
	| Solubility = 450 g/L (10 °C)<ref name=r5p5/>		| Solubility = 450 g/L (10 °C)<ref name=r5p5/>
	| pKa = 1.6<ref name=r5p5/>		| pKa = 1.6<ref name=r5p5/>
	| pKb = 12.4<ref name=r5p5/>}}		| pKb = 12.4<ref name=r5p5/>}}
	| Section7 = {{Chembox Hazards		|Section7={{Chembox Hazards
	| MainHazards =		| MainHazards =
	| FlashPt =		| FlashPt =
			| AutoignitionPtC = 250
	| Autoignition =250 °C<ref name=r5p6>Report 5 (1995) p. 6</ref>		| AutoignitionPt_ref = <ref name=r5p6>Report 5 (1995) p. 6</ref>
	| RPhrases = {{R15}} {{R21}} {{R22}} {{R29}} {{R36}} {{R38}}
			| GHSPictograms = {{GHS02}}{{GHS05}}{{GHS06}}{{GHS07}}
	| SPhrases = {{S3}} {{S9}} {{S35}} {{S36}} {{S37}} {{S38}} {{S39}} {{S16}} {{S23}} {{S51}}
			| GHSSignalWord = Danger
			| HPhrases = {{H-phrases|228|302|311|314|315|319|332|335}}
			| PPhrases = {{P-phrases|210|240|241|260|261|264|270|271|280|301+312|301+330+331|302+352|303+361+353|304+312|304+340|305+351+338|310|312|321|322|330|332+313|337+313|361|362|363|370+378|403+233|405|501}}
	}}		}}
	}}		}}
	'''Sodium ethyl xanthate''' (SEX)<ref>{{cite book|author=Caroline Cooper|title=Organic Chemist's Desk Reference|url=http://books.google.com/books?id=ahbUc5M0I5AC&pg=PA123|accessdate=22 February 2011|date=23 July 2010|publisher=CRC Press|isbn=9781439811641|pages=123 (Acronyms and Miscellaneous Terms used in Describing Organic Molecules)}}</ref> is an ] with the chemical formula CH<sub>3</sub>CH<sub>2</sub>OCS<sub>2</sub>Na. It is a pale yellow powder, which characteristically hydrolyzes to release malodorous products. Sodium ethyl xanthate is predominantly used in the mining industry as a ].		'''Sodium ethyl xanthate''' ('''SEX''')<ref>{{cite book|author=Caroline Cooper|title=Organic Chemist's Desk Reference|url=https://books.google.com/books?id=ahbUc5M0I5AC&pg=PA123|accessdate=22 February 2011|date=23 July 2010|publisher=CRC Press|isbn=978-1-4398-1164-1|pages=123 (Acronyms and Miscellaneous Terms used in Describing Organic Molecules)}}</ref> is an ] with the chemical formula {{chem2|CH3CH2OCS2Na}}. It is a pale yellow powder, which is usually obtained as the dihydrate. Sodium ethyl xanthate is used in the mining industry as a ].<ref name=Ullmann>{{cite encyclopedia|author=Kathrin-Maria Roy|title=Xanthates|encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry|year=2005|publisher= Wiley-VCH|location=Weinheim|doi=10.1002/14356007.a28_423|isbn=3527306730}}</ref> A closely related ] (KEX) is obtained as the anhydrous salt.
	==Production==		==Production==
			Akin to the preparation of most ]s, sodium ethyl xanthate can be prepared by treating ] with ]:<ref>{{cite journal|author1=Ingram, G. |author2=Toms, B. A. |title=The reactions of sodium ethyl xanthate with ethanol and with water. |journal=Journal of the Chemical Society (Resumed)|year=1961|pages=117–127|doi=10.1039/JR9610000117}}</ref>
	Xanthantes are prepared by the action of alcohols on carbon disulfide:
			{{indent|5}}{{chem2|CH3CH2ONa + CS2 -> CH3CH2OCS2Na}}
	:CH<sub>3</sub>CH<sub>2</sub>ONa + CS<sub>2</sub> → CH<sub>3</sub>CH<sub>2</sub>OCS<sub>2</sub>Na
		⚫	==Properties and reactions==
		⚫	Sodium ethyl xanthate is a pale yellow powder. Its aqueous solutions are stable at high pH if not heated. It rapidly hydrolyses at ] less than 9 at 25 °C. It is the conjugate base of the ], a strong acid with p''K''<sub>a</sub> of 1.6 and p''K''<sub>b</sub> estimated as 12.4 for the ].<ref>{{cite journal |doi=10.1021/jo01324a018|title=General acid-catalyzed decomposition of alkyl xanthates |year=1979 |last1=Millican |first1=Robert J. |last2=Sauers |first2=Carol K. |journal=The Journal of Organic Chemistry |volume=44 |issue=10 |pages=1664–1669}}</ref> Sodium ethyl xanthate easily adsorbs on the surface of many sulfide minerals,<ref name=r5p6>Report 5 (1995) p. 6</ref> a key step in ].
			Xanthates are susceptible to hydrolysis and oxidation<ref name=r5p14>Report 5 (1995) pp. 14–16</ref> at low pH:
⚫	==Properties==
			:{{chem2|C2H5OCS2Na + H(+) -> C2H5OH + CS2 + Na(+)}}
⚫	Sodium ethyl xanthate is a pale yellow powder. It is relatively stable at high pH and rapidly hydrolyses at pH <9 at 25 °C. It is the conjugate base of the unknown strong acid with p''K''<sub>a</sub> of 1.6 and p''K''<sub>b</sub> estimated as 12.4 for the ]. Sodium ethyl xanthate easily adsorbs on the surface of solid sulfides.<ref name=r5p6>Report 5 (1995) p. 6</ref>
			Oxidation gives ]:
	===Decomposition in water===
			:{{chem2|4C2H5OCS2Na + 2H2O + O2 -> 2(C2H5OCS2)2 + 4 NaOH}}
	Sodium ethyl xanthate decomposes in water increases with decreasing ] and with increasing temperature. Three pathways are proposed:<ref name=r5p14>Report 5 (1995) pp. 14–16</ref>
	'''A.''' Dissociation into xanthic acid and then to carbon disulfide and alcohol.
	:C<sub>2</sub>H<sub>5</sub>OCS<sub>2</sub>Na + H<sub>2</sub>O → C<sub>2</sub>H<sub>5</sub>OCS<sub>2</sub>H + NaOH
	:C<sub>2</sub>H<sub>5</sub>OCS<sub>2</sub>H → CS<sub>2</sub> + C<sub>2</sub>H<sub>5</sub>OH
	'''B.''' Oxidation to dixanthogen.
	:2 C<sub>2</sub>H<sub>5</sub>OCS<sub>2</sub><sup>–</sup> + H<sub>2</sub>O + O<sub>2</sub>O → (C<sub>2</sub>H<sub>5</sub>OCS<sub>2</sub>)<sub>2</sub> + 2 OH<sup>–</sup>
	'''C.''' Hydrolytic decomposition
	:6 C<sub>2</sub>H<sub>5</sub>OCS<sub>2</sub><sup>–</sup> + 3 H<sub>2</sub>O + O<sub>2</sub>O → 6 C<sub>2</sub>H<sub>5</sub>OH + CO<sub>3</sub><sup>2–</sup> + 3 CS<sub>2</sub> + 2 CS<sub>3</sub><sup>2–</sup>
	Reactions A and B are minor and require acidic conditions. Reaction C proceeds in neutral or alkaline pH and is self-accelerating, as it is catalysed by the alcohol formed as a product. Its rate increases with concentration of the reagents and with temperature, from 1.1%/day at 20 °C to 4.6%/day at 40 °C for a 10% solution at pH=10. A decrease in pH from 10 to 6.5 increases the decomposition rate from 1.1%/day to 16%/day. Decomposition is also accelerated by the presence of metals, such as copper, iron, lead or zinc, which act as a catalyst.<ref name=r5p14/>
	==Detection==		==Detection==
	Sodium ethyl xanthate can be identified through optical absorption peaks in the infrared (1179, 1160, 1115, 1085 cm<sup>−1</sup>) and ultraviolet (300 nm) ranges. There are at least six chemical detection methods:		Sodium ethyl xanthate can be identified through optical absorption peaks in the ] (1179, 1160, 1115, 1085&nbsp;cm<sup>−1</sup>) and ] (300&nbsp;nm) ranges. There are at least six chemical detection methods:
	#''Iodometric method '' relies on oxidation to dixanthogen by iodine, with the product detected with a starch indicator. This method is however is not selective and suffers from interferences with other sulfur-containing chemicals.<ref name=r5p8>Report 5 (1995) p. 8</ref>		#''Iodometric method '' relies on oxidation to dixanthogen by iodine, with the product detected with a starch indicator. This method is however is not selective and suffers from interferences with other sulfur-containing chemicals.<ref name=r5p8>Report 5 (1995) p. 8</ref>
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	#In the ''acid-base detection method'', a dilute aqueous xanthate solution is reacted with a copious amount of 0.01 M ] yielding carbon disulfide and alcohol, which are evaluated. The excess acid and impurities are removed through filtering and titration.<ref name=r5p9>Report 5 (1995) p. 9</ref>		#In the ''acid-base detection method'', a dilute aqueous xanthate solution is reacted with a copious amount of 0.01 M ] yielding carbon disulfide and alcohol, which are evaluated. The excess acid and impurities are removed through filtering and titration.<ref name=r5p9>Report 5 (1995) p. 9</ref>
	#In the ''argentometric method'', sodium ethyl xanthate is reacted with ] in a dilute solution. The resulted silver xanthate is detected with 10% aqueous solution of ]. The drawbacks of this method are high cost of silver and blackening of silver xanthate by silver nitrate that reduces the detection accuracy.<ref name=r5p9/>		#In the ''argentometric method'', sodium ethyl xanthate is reacted with ] in a dilute solution. The resulted silver xanthate is detected with 10% aqueous solution of ]. The drawbacks of this method are high cost of silver and blackening of silver xanthate by silver nitrate that reduces the detection accuracy.<ref name=r5p9/>
	#In the ''mercurimetric method'', xanthate is dissolved in 40% aqueous solution of dimethylamine, followed by heating and titration with ''O''-hydroxymercuribenzoate. The product is detected with ].<ref name=r5p9/>		#In the ''mercurimetric method'', xanthate is dissolved in 40% aqueous solution of dimethylamine, followed by heating and titration with ''o''-hydroxymercuribenzoate. The product is detected with ].<ref name=r5p9/>
	#''Perchloric acid method'' involves dissolution of xanthate in water-free ]. The product is titrated with ] and detected with ].<ref name=r5p9/>		#''Perchloric acid method'' involves dissolution of xanthate in water-free ]. The product is titrated with ] and detected with ].<ref name=r5p9/>
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	==Applications==		==Applications==
	Sodium ethyl xanthate is predominantly used in the mining industry as ] for recovery of metals, such as copper, nickel, silver or gold, as well as solid metal sulfides or oxides from ore ]. This application has been introduced by Cornelius H. Keller in 1925. Other applications include ], ] and an additive to rubber to protect it against oxygen and ozone.<ref name=r5p2>Report 5 (1995), p. 2, citing Rao, R.S., “Xanthates and Related Compounds”, Marcel Dekker, New York, 1971 ISBN 0824715632 and Keller, C.H. (1925) {{US Patent|1554216}} "Concentration of gold, sulphide minerals and uranium oxide minerals by flotation from ores and metallurgical plant products"</ref>		Sodium ethyl xanthate is used in the mining industry as ] for recovery of metals, such as copper, nickel, silver or gold, as well as solid metal sulfides or oxides from ore ]. This application was introduced by Cornelius H. Keller in 1925. Other applications include ], ], and an additive to rubber to protect it against oxygen and ozone.<ref name=r5p2>Report 5 (1995), p. 2, citing Rao, R.S., “Xanthates and Related Compounds”, Marcel Dekker, New York, 1971 {{ISBN|0-8247-1563-2}} and Keller, C.H. (1925) {{US Patent|1554216}} "Concentration of gold, sulphide minerals and uranium oxide minerals by flotation from ores and metallurgical plant products"</ref>
	The mechanism of flotation enhancement is as follows. The polar part of xanthate molecule attaches to the ore particles with the non-polar hydrocarbon part sticking out and forming a hydrophobic layer. Then the particles are brought to the water surface by air bubbles. Only a small amount of about 300 g/tonne of ore is required for efficient separation. The efficiency of the hydrophobic action increases, but the selectivity to ore type decreases with increasing length of the hydrocarbon chain in xanthates. The chain is shortest in sodium ethyl xanthate that makes is highly selective to copper, nickel, lead, gold and zinc ores. Aqueous solution (10%) with pH=7–11 are normally used in the process.<ref name=r5p13>Report 5 (1995) p. 13</ref>
⚫	In 2000, Australia produced up to 10,000 ]s of sodium ethyl xanthate and imported about 6,000 tonnes, mostly from China.<ref>Report 5s (2000) p. 1</ref> The material produced in Australia is the so-called 'liquid sodium ethyl xanthate' that refers to a 40% aqueous solution of the solid.<ref>Report 5s (2000) p. 3</ref> It is obtained by reacting carbon disulfide with sodium hydroxide and ethanol in a closed process.<ref name=5spv/> Its density is 1.2 g/cm<sup>3</sup> and the freezing point is −6 °C.<ref>Report 5s (2000) p. 7</ref>
		⚫	In 2000, Australia produced up to 10,000 ]s of sodium ethyl xanthate and imported about 6,000 tonnes, mostly from China.<ref>Report 5s (2000) p. 1</ref> The material produced in Australia is the so-called 'liquid sodium ethyl xanthate' that refers to a 40% aqueous solution of the solid.<ref>Report 5s (2000) p. 3</ref> It is obtained by treating carbon disulfide with sodium hydroxide and ethanol.<ref name=5spv/> Its density is 1.2 g/cm<sup>3</sup> and the freezing point is −6 °C.<ref>Report 5s (2000) p. 7</ref>
	Other applications include ]s and ]s and as an additive to rubber to protect it against oxygen and ].
	==Safety==		==Safety==
	Sodium ethyl xanthate has moderate oral and dermal toxicity in animals and is irritating to eyes and skin.<ref name=5spv>Report 5s (2000) p. v</ref> It is especially toxic to aquatic life and therefore its disposal is strictly controlled.<ref name=r5p43>Report 5 (1995) pp. 43–45</ref> Median lethal dose for (male albino mice, oral, 10% solution at pH~11) is 730 mg/kg of body weight, with most deaths occurring in the first day. The most affected organs were the central nervous system, liver and ].<ref name=r5p17>Report 5 (1995) p. 17</ref>		Sodium ethyl xanthate has moderate oral and dermal toxicity in animals and is irritating to eyes and skin.<ref name=5spv>Report 5s (2000) p. v</ref> It is especially toxic to aquatic life and therefore its disposal is strictly controlled.<ref name=r5p43>Report 5 (1995) pp. 43–45</ref> Median lethal dose for (male albino mice, oral, 10% solution at pH~11) is 730 mg/kg of body weight, with most deaths occurring in the first day. The most affected organs were the central nervous system, liver and ].<ref name=r5p17>Report 5 (1995) p. 17</ref>
	Since 1993, sodium ethyl xanthate is classified as a Priority Existing Chemical in Australia, meaning that its manufacture, handling, storage, use or disposal may result in adverse health or environment effects. This decision was justified by the widespread use of the chemical in industry and its decomposition to the toxic and flammable carbon disulfide gas. From two examples of sodium ethyl xanthate spillage in Australia, one resulted in evacuation of 100 people and hospitalization of 6 workers who were exposed to the fumes. In another accident, residents of the spillage area complained of headache, dizziness and nausea.<ref name=r5p1>Report 5 (1995) p. 1</ref> Consequently, during high-risk sodium ethyl xanthate handling operations, workers are required by the Australian regulations to be equipped with protective clothing, anti-static gloves, boots and full-face ]s or ]es.<ref>Report 5s (2000) p. vi</ref>		Since 1993, sodium ethyl xanthate is classified as a Priority Existing Chemical in Australia, meaning that its manufacture, handling, storage, use or disposal may result in adverse health or environment effects. This decision was justified by the widespread use of the chemical in industry and its decomposition to the toxic and flammable carbon disulfide gas. From two examples of sodium ethyl xanthate spillage in Australia, one resulted in evacuation of 100 people and hospitalization of 6 workers who were exposed to the fumes. In another accident, residents of the spillage area complained of headache, dizziness, and nausea.<ref name=r5p1>Report 5 (1995) p. 1</ref> Consequently, during high-risk sodium ethyl xanthate handling operations, workers are required by the Australian regulations to be equipped with protective clothing, anti-static gloves, boots and full-face ]s or ].<ref>Report 5s (2000) p. vi</ref>
	==References==		==References==
	{{reflist|2}}		{{reflist|30em}}
	==Bibliography==		==Bibliography==
	*Priority existing chemical Report No. 5 , , Dep. of Health and Ageing, Australian Government (1995) ISBN 0-644-35283-3		*Priority existing chemical Report No. 5 , , Dep. of Health and Ageing, Australian Government (1995) {{ISBN|0-644-35283-3}}
	*Priority Existing Chemical. Secondary Notification Assessment Report No. 5S , National Industrial Chemicals Notification and Assessment Scheme, Dep. of Health and Ageing, Australian Government, (February 2000) ISBN 0-642-42198-6		*Priority Existing Chemical. Secondary Notification Assessment Report No. 5S , National Industrial Chemicals Notification and Assessment Scheme, Dep. of Health and Ageing, Australian Government, (February 2000) {{ISBN|0-642-42198-6}}
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