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

CHAPTER V.*
THE METALLUBGY OF ANTIMONY.
THE principal ore for the extraction of antimony is sulphide of
antimony or stibnite, commonly known as antimony-glance. The
other ores—cervantite or antimony-ochre, kermesite, valentinite,
senarmontite, which occur only in small quantities in nature—
together with the fumes and slags from the previous smelting of
antimony, are generally mixed up with antimony-glance preparatory
to smelting. Dry methods are generally adopted for the extraction
of the metal, or of the metal in different combinations, while
the proposals for the use of wet processes or of electro-metallurgical
methods have not yet found practical application. The more or
less pure sulphide of antimony is called ''crude antimony," and the
refined metal itself is called "antimony regulus."
I. EXTRACTION BY DRY METHODS.
A. Preparation of Products for the Extraction of Metallic
Antimoiiy.
1. Liquation of Crude Antimony.—Ores containing more than 90
per cent, of the sulphide do not require any further treatment, and
are considered to be crude antimony. Ores containing less than 90
per cent, and more than 40 or 50 per cent, are subjected to the
liquation process for the production of crude antimony. The best
size of the pieces of ore for this treatment is walnut size. Smallersized
ore or ores of poorer quality are generally worked up for the
production of the metal.
The maintenance of the proper temperature in the liquation process
is very important, in order to obtain the best result. If the temperature
is above a red heat the sulphide is volatilised, and if the tem-
* In the compilation of this chapter, use has been made of the information
contained in the standard metallurgical works of Phillips and Bauerman, of Bruno
Kerl, and of Carl Schnabel in drawing up the descriptions of the older methods.
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