Magnesium sulfide

"MgS" redirects here. For other uses, see MGS (disambiguation).

Magnesium sulfide
Other names Niningerite
Identifiers
CAS number	12032-36-9 Y
Properties
Molecular formula	MgS
Molar mass	56.38 g/mol
Density	2.68 g/cm3
Melting point	>2000 °C
Solubility in water	decomposes
Structure
Crystal structure	Halite (cubic), cF8
Space group	Fm3m, No. 225
Coordination geometry	octahedral
Hazards
EU Index	Not listed
Related compounds
Other anions	Magnesium oxide
Other cations	Calcium sulfide Strontium sulfide Barium sulfide
Y sulfide (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Magnesium sulfide is an inorganic compound with the formula MgS. It is a white crystalline material but often is encountered in an impure form that is brown and non-crystalline powder. It is generated industrially in the production of metallic iron.

Preparation and general properties

MgS is formed by the reaction of sulfur or hydrogen sulfide with magnesium. It crystallizes in the rock salt structure, although the zinc blende structure might be anticipated.^[1] The chemical properties of MgS resemble those of related ionic sulfides such as those of Na, Ba, Ca. It reacts with oxygen to form the corresponding sulfate, magnesium sulfate. MgS reacts with water to give hydrogen sulfide and magnesium hydroxide.^[2]

Applications

In the BOS steelmaking process, sulfur is the first element to be removed. Sulfur is removed from the impure blast furnace iron by the addition of several hundred kilograms of magnesium powder by a lance. Magnesium sulfide is formed, which then floats on the molten iron and is removed.^[3]

MgS is a wide band-gap direct semiconductor of interest as a blue-green emitter, a property that has been known since the early 1900s.^[4]

Occurrence

Aside from being a component of some slags, MgS is a rare nonterrestial mineral niningerite detected in some meteorites. MgS is also found in the circumstellar envelopes of certain evolved carbon stars, i. e., those with C/O > 1.^[5]

Safety

MgS evolves hydrogen sulfide upon contact with moisture.

References

1. ^ Guntert, O. J.; Faessler, A. "Lattice constants of the alkaline earth sulfides MgS, CaS, SrS, and BaS" Zeitschrift für Kristallographie, Kristallgeometrie, Kristallphysik, Kristallchemie (1956), volume 107, pages 357-61.
2. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
3. ^ Irons, G. A.; Guthrie, R. I. L. "Kinetic aspects of magnesium desulfurization of blast furnace iron" Ironmaking and Steelmaking (1981), volume 8, pp.114-21.
4. ^ Tiede, E. "Reindarstellung von Magnesiumsulfid und seine Phosphorescenz. I (Preparation of pure magnesium sulfide and its phosphorescence. I)" Berichte der Deutschen Chemischen Gesellschaft (1916), volume 49, pages 1745-9.
5. ^ Goebel, J. H., and Moseley, S. H., "MgS Grain Component in Circumstellar Shells," Astrophysical Journal (Letters) 290, L35 (1985)