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Antimony Trisulfide (Stibnite, Antimonite)

Author: Hans Lohninger

Ref.: Rob Lavinsky, iRocks.com
Antimony trisulfide, Sb2S3, is a sulfide mineral commonly called stibnite or antimonite. Antimony trisulfide exists as a gray/black crystalline solid (orthorombic crystals) and an amorphous red-orange powder. It turns black due to oxidation by air. Antimony trisulfide is the most important source for antimony. It is insoluble in water and melts at 550C. The chemical symbol of antimony (Sb) is derived from stibnite.

Amorphous (red to yellow-orange) antimony trisulfide can be prepared by treating an antimony trichloride solution with hydrogen sulfide:

2 SbCl3 + 3 H2S Sb2S3 + 6 HCl

When melting antimony trisulfide with iron at approx. 600C the following reaction yields elementary antimony:

Sb2S3 + 3 Fe Sb + 3 FeS

Sb2S3 is used as a pigment, in pyrotechnics (glitter and fountain mixtures) and on safety matches. In combination with antimony oxides it is also used as a yellow pigment in glass and porcelain. Antimony trisulfide photoconductors are used in vidicons for CCTV.




Last Update: 2011-05-26