Editing Sodium cyanide (section)

==Applications==
===Cyanide mining===
{{Anchor|Sodium gold cyanide|Sodium dicyanoaurate}}
[[Gold cyanidation]] (also known as the cyanide process) is the dominant technique for extracting [[gold]], much of which is obtained from low-grade [[ore]]. More than 70% of cyanide consumption globally is used for this purpose.  The  application exploits the high affinity of gold(I) for cyanide, which induces gold metal to oxidize and dissolve in the presence of air (oxygen) and water, producing the salt '''sodium dicyanoaurate''' (or sodium gold cyanide) ({{chem2|NaAu(CN)2}}):<ref name=Ullmann/>
:{{chem2|4 Au  +  8 NaCN  +  O2  +  2 H2O  →  4 Na[Au(CN)2]  +  4 NaOH}}

A similar process uses [[potassium cyanide]] (KCN, a close relative of sodium cyanide) to produce [[potassium dicyanoaurate]] ({{chem2|KAu(CN)2}}).

These soluble forms of gold (and silver) can be converted back to the metals by electrolysis.

===Chemical feedstock===
Some commercially significant chemicals are derived from cyanide: [[cyanuric chloride]], [[cyanogen chloride]], and [[cyanogen]].<ref name=Ullmann/> 

Several specialty [[nitrile]]s may be produced by alkylation of cyanide, a strong [[nucleophile]]. Illustrative is the synthesis of [[benzyl cyanide]] by the reaction of [[benzyl chloride]] and sodium cyanide:<ref>{{cite journal|last1=Adams|first1=Roger|last2=Thal|first2=A. F.|title=Benzyl cyanide|journal=Organic Syntheses|date=1922|volume=2|page=9|doi=10.15227/orgsyn.002.0009}}</ref>
:{{chem2| C6H5CH2Cl + NaCN -> C6H5CH2CN +  NaCl}}

===Electroplating===
Cyanide baths (solutions) of metal ions are used to [[electroplating|electroplate]] many metals, including [[platinum]], gold, and silver. [[Cadmium]] plating gives excellent corrosion resistance and is achieved using [[cadmium oxide]] and sodium cyanide.<ref>{{cite book |doi=10.1002/14356007.a04_499 |chapter=Cadmium and Cadmium Compounds |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2000 |last1=Schulte-Schrepping |first1=Karl-Heinz |last2=Piscator |first2=Magnus |isbn=978-3-527-30385-4 }}</ref> Copper 'strikes' (thin high quality layers) are traditionally formed using cyanide electroplating, these thin interstitial layers allow adhesion between metals that are usually incompatible, such as chromium and aluminium.{{cn|date=March 2025}}

===Niche uses===
Being highly toxic, sodium cyanide is used to kill or stun rapidly such as in collecting jars used by [[entomologist]]s and in widely illegal [[cyanide fishing]].

It was used as an [[insecticide]], [[rodenticide]] and [[Antibiotic|antibacterial]], but these uses were cancelled by the [[United States Environmental Protection Agency|EPA]] in 1987.<ref>{{Cite web |date=September 1994 |title=Reregistration Eligibility Decision (R.E.D. Facts) Sodium cyanide |url=https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-074002_1-Sep-94.pdf |website=United States Environmental Protection Agency}}</ref>