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

THE METALLUKi'iY OF ANTIMONY.
A good example showing the receiving vessels placed uutside can
be seen from fig. 5, as used in Hungary.
An intermediate form is shown in fitr. 6.
(b) Continuous Working.
a. In Tubes.—Liquation in tube furnaces gives bettor results than
those obtained with pot furnaces, the consumption of fuel beinir less and
the production higher. Fi[i. 7 shows the construction of the furnaces
used at Malbosc.* while fig. 8 shows another type ox tube furnaces.
The tubes are arranged in groups of four, placed over four receivers,
I, which are carried on carriages, c, with wheels There are three
FIG. 6.
grates, d, from which the flame, after playing around the tubes, a,
escapes into the chimney, e is a hole in the side o: the tube, by means
of which the residue is drawn out, the size being :!-7 ins. wide and 4'7
ins. high. The hole is closed with a clay plug or with a luted plate.
The size of the tubes is 3 ft. 3 ins. high, 10 ins. in diameter at the upper
end, and 7 J ins. in diameter at the bottom, their walls being 0*6 to 0"8
inch thick.
It must be noted that a newly built furnace must be heated to a
bright red heat for forty-eight hours before a charge can be started.
The regulation of the temperature is an important factor, and is adjusted
according to the colour of the product, which should be of a
bluish tint, while a red colour is an indication that the heat has been
too great.
* This has been replaced by the apparatus patented by Herrenschmidt.
73