Zinc ammonium chloride
{{Chembox
| ImageFile =
| ImageSize =
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| IUPACName = diammonium tetrachlorozincate(2-)
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 14639-97-5
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 61754
| EC_number = 238-687-6
| ChemSpiderID = 55644
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = NK9T00M5VV
| UNNumber = 1759
| StdInChI=1S/4ClH.2H3N.Zn/h4*1H;2*1H3;/q;;;;;;+2/p-2
| StdInChIKey = QOQUXKCHSZSKOT-UHFFFAOYSA-L
| SMILES = [NH4+].[NH4+].Cl[Zn-2](Cl)(Cl)Cl
}}
|Section2={{Chembox Properties
| H=8|Cl=4|Zn=1|N=2
| MolarMass =
| Appearance =
| Density = 1.91 g/cm3
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|Section3={{Chembox Hazards
| MainHazards =
| GHSPictograms = {{GHS05}}{{GHS07}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|314|315|400|411}}
| PPhrases = {{P-phrases|260|264|270|273|280|301+312|301+330+331|302+352|303+361+353|304+340|305+351+338|310|321|330|332+313|362|363|391|405|501}}
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Zinc ammonium chloride is the inorganic compound with the formula (NH4)2ZnCl4. It is the ammonium salt of tetrachlorozincate. It used as a flux in the process of hot-dip galvanizing.[http://www.chemicaldictionary.org/dic/Z/Zinc-ammonium-chloride_304.html Zinc Ammonium Chloride] {{Webarchive|url=https://web.archive.org/web/20171116022032/http://www.chemicaldictionary.org/dic/Z/Zinc-ammonium-chloride_304.html}}{{cite book|last=Vulte|first=H.T.|title=Laboratory Manual of Inorganic Preparations |year=1902 |page=72 |publisher=Read Books |isbn=1408608405}}{{cite journal|title=X-Ray Structural Study of the Successive Phase Transitions in Ammonium Tetrachlorozincate, (NH4)2ZnCl4. I. Crystal Structure Determination|author=Hironori Matsunaga |journal=J. Phys. Soc. Jpn. |year=1982 |volume=51|issue=3|pages=864–872 |doi=10.1143/JPSJ.51.864|bibcode=1982JPSJ...51..864M}}
Uses
Steel to be galvanized passes through an acidic cleaning process to remove iron oxide "mill scale". After this process, the surface of the steel is very active and oxide layers begin forming immediately upon exposure to the atmosphere. Zinc ammonium chloride flux in aqueous solution is applied to the steel to reduce any oxides that are formed and/or inhibit them from forming altogether. This allows the molten zinc in the proceeding galvanizing step to maximally adhere to and alloy with the surface of the steel.{{cite web|title=The Hot-Dip Galvanizing Process |url=http://www.hotdipgalvanizing.com/hot_dip_galvanizing_process/index.html |publisher=V&S Hot Dip Galvanzing}}{{cite web |title=Galvanizing Fluxes |url=http://www.zaclon.com/prods_galvflux.html |publisher=Zaclon LLC}}