Nickel sulfide is any inorganic compound with the formula NixSy. These compounds range in color from bronze (Ni3S2) to black (NiS2). The nickel sulfide with simplest stoichiometry is NiS, also known as the mineral millerite. From the economic perspective, Ni9S8, the mineral pentlandite, is the chief source of mined nickel. Other minerals include heazlewoodite (Ni3S2) and polydymite (Ni3S4), and the mineral Vaesite (NiS2).[1] Some nickel sulfides are used commercially as catalysts.

Nickel sulfide
Names
IUPAC name
Nickel(II) sulfide
Other names
nickel sulfide, nickel monosulfide, nickelous sulfide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.037.113 Edit this at Wikidata
EC Number
  • 234-349-7
RTECS number
  • QR9705000
UNII
  • [Ni]=S
  • [Ni+2].[S-2]
Properties
NiS
Molar mass 90.7584 g mol−1
Appearance black solid
Odor Odorless
Density 5.87 g/cm3
Melting point 797 °C (1,467 °F; 1,070 K)
Boiling point 1,388 °C (2,530 °F; 1,661 K)
insoluble
Solubility degraded by nitric acid
+190.0·10−6 cm3/mol
Structure
hexagonal
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
may cause cancer by inhalation
GHS labelling:
GHS07: Exclamation mark
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure

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Like many related materials, nickel sulfide adopts the nickel arsenide motif. In this structure, nickel is octahedral and the sulfide centers are in trigonal prismatic sites.[2]

Coordination environments in nickel sulfide
Nickel Sulfur
   
octahedral trigonal prismatic

NiS has two polymorphs. The α-phase has a hexagonal unit cell, while the β-phase has a rhombohedral cell. The α-phase is stable at temperatures above 379 °C (714 °F), and converts into the β-phase at lower temperatures. That phase transition causes an increase in volume by 2–4%.[3][4][5]

Synthesis and reactions

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The precipitation of solid black nickel sulfide is a mainstay of traditional qualitative inorganic analysis schemes, which begins with the separation of metals on the basis of the solubility of their sulfides. Such reactions are written:[6]

Ni2+ + H2S → NiS + 2 H+

Many other more controlled methods have been developed, including solid state metathesis reactions (from NiCl2 and Na2S) and high temperature reactions of the elements.[7]

The most commonly practiced reaction of nickel sulfides involves conversion to nickel oxides. This conversion involves heating the sulfide ores in air:[1]

NiS + 1.5 O2 → NiO + SO2

Occurrence

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Natural

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The mineral millerite is also a nickel sulfide with the molecular formula NiS, although its structure differs from synthetic stoichiometric NiS due to the conditions under which it forms. It occurs naturally in low temperature hydrothermal systems, in cavities of carbonate rocks, and as a byproduct of other nickel minerals.[8]

 
Millerite crystals

In nature, nickel sulfides commonly occur as solid solutions with iron sulfides in minerals such as pentlandite and pyrrhotite. These minerals have the formula Fe9-xNixS8 and Fe7-xNixS6, respectively. In some cases they are high in nickel (larger values of x).

In glass manufacturing

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Float glass contains a small amount of nickel sulfide, formed from the sulfur in the fining agent Na
2
SO
4
and the nickel contained in metallic alloy contaminants.[9]

Nickel sulfide inclusions are a problem for tempered glass applications. After the tempering process, nickel sulfide inclusions are in the metastable alpha phase. The inclusions eventually convert to the beta phase (stable at low temperature), increasing in volume and causing cracks in the glass. In the middle of tempered glass, the material is under tension, which causes the cracks to propagate and leads to spontaneous glass fracture.[10] That spontaneous fracture occurs years or decades after glass manufacturing.[9]

References

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  1. ^ a b Kerfoot, Derek G. E. (2005). "Nickel". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_157. ISBN 978-3527306732.
  2. ^ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
  3. ^ Bishop, D.W.; Thomas, P.S.; Ray, A.S. (1998). "Raman spectra of nickel(II) sulfide". Materials Research Bulletin. 33 (9): 1303. doi:10.1016/S0025-5408(98)00121-4.
  4. ^ "NiS and Spontaneous Breakage". Glass on Web. Nov 2012. Archived from the original on 2013-06-12.
  5. ^ Bonati, Antonio; Pisano, Gabriele; Royer Carfagni, Gianni (12 October 2018). "A statistical model for the failure of glass plates due to nickel sulfide inclusions". Journal of the American Ceramic Society. 102 (5): 2506–2521. doi:10.1111/jace.16106. S2CID 140055629.
  6. ^ O.Glemser "Nickel Sulfide" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 2. p. 1551.
  7. ^ leading reference can be found in: Shabnam Virji, Richard B. Kaner, Bruce H. Weiller "Direct Electrical Measurement of the Conversion of Metal Acetates to Metal Sulfides by Hydrogen Sulfide" Inorg. Chem., 2006, 45 (26), pp 10467–10471.doi:10.1021/ic0607585
  8. ^ Gamsjager H. C., Bugajski J., Gajda T., Lemire R. J., Preis W. (2005) Chemical Thermodynamics of Nickel, Amsterdam, Elsevier B.V.
  9. ^ a b Karlsson, Stefan (30 April 2017). "Spontaneous fracture in thermally strengthened glass – A review & outlook". Ceramics – Silikaty: 188–201. doi:10.13168/cs.2017.0016. Retrieved 16 August 2019.
  10. ^ Barry, John (12 January 2006). "The Achille Heel of a Wonderful Material: Toughened Glass". Glass on Web. Retrieved 16 August 2019.