A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...

THE ANTIMONY PREPARATIONS AND THEIR USES. 173
8. Mordant for Dyeing.
Fluoride of antimony, SbF3J is used as a mordant for dyeing.
According to Rad (1890), the following reaction occurs :—
(NH4)HPO4 + 26HF + 4Sb2O3=8SbF3.2NH4F + 12H2O + H3PO4.
9. Vulcanising Eubber.
The so-called Goldschwefel (antimony pentasulphide, Sb2S5) is used
for this purpose. It is thus made :—Powdered antimony sulphide is
heated with sulphur and sodium hydroxide:
4Sb2S3 + 8S +18HNaO = 5Na3SbS4 + 3NaSbO3 + 92^0.
From this solution the so-called Schlippe's salt, Na3SbS4.9H2O
crystallises out. HC1 is then added to it:
NaSbS4 + 6HC1 = 6NaCl + 3H2S + Sb2S5.
According to Bertsch and Harmsen, the following reactions may
occur:—
II. 10Na3SbS4 + 30HC1 + 3Sb2O5 = 8Sb2S5 + 30NaCl + 15H2O.
10. Coating Articles.
Metallic antimony can be used to paint objects with, giving them a
polisted-steel appearance. It is called "iron black" (Eisenschwarz)
in trade, and can be obtained by precipitating a solution of antimony
salt with zinc. It can also be used for bronzing gypsum.
The beurre tfantimoine (SbCl3) can be used for bronzing copper
and iron, and preserving them from being oxidised by the deposition
of a thin layer produced by the action of the copper or the iron upon
the chloride.
M. George Hyvert recommended the use of antimony fluoride to
get rid of vegetable parasites that are so injurious to iron structures
and rails."*
11. For the Manufacture of Aniline Yellow and Aniline Red.
Antimonic acid, HSbO3 + 2H2O, has replaced arsenic acid in the
manufacture of aniline yellow and aniline red.
* At present the railway companies in England and in the United States use a
solution of arsenic compounds for this puTpose.