A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
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THE ANTIMONY PKEPAEATIONS AND THEIK USES. 153<br />
black powder. Since then Pe'cheux has been able to obtain the<br />
alloys: SbAl30, density = 2-73* SbAl35, density =2*7; SbAlgg, density<br />
= 2-662; and SbAl40, density = 2*598. The melting-point of these<br />
four alloys is between 760* and 730°, while those of antimony and<br />
aluminium are 460° and 650° respectively. They expand on solidifying,<br />
are sonorous, offer resistance to filing, but are somewhat<br />
brittle, and can be slightly bent. They are of a bluish-gray colour,<br />
and do not alter in air or water at ordinary temperatures. The<br />
alloy SbAl^, however, decomposes water at 100° C. The lightness,<br />
malleability, and durability of these alloys may render them useful in<br />
the construction of ships for the navy, submarine vessels, automobile<br />
conveyances, and air-ships.<br />
An alloy of antimony and arsenic is very fusible, very hard and<br />
brittle, and is not of practical use.<br />
An alloy of antimony and nickel is brittle, and has a lead colour.<br />
Alloys of antimony and bismuth have the following composition,<br />
according to Holzmann:—<br />
Sb.<br />
lOCf<br />
54*0<br />
37-1<br />
22*7<br />
12-8<br />
8*9<br />
Composition<br />
Bis.<br />
46-0<br />
62*9<br />
77*3<br />
87-2<br />
91*1 .<br />
100<br />
Atomic<br />
Formula.<br />
Sb<br />
Sb2Bi<br />
SbBi<br />
SbBL^<br />
SbBi4<br />
SbBL<br />
Bi<br />
Found.<br />
6*713<br />
7*864<br />
8*392<br />
8*886<br />
9*277<br />
9*435<br />
9*823<br />
Specific Gravity.<br />
Calculated.<br />
7-856<br />
S*385<br />
8*888<br />
9-272<br />
9*433<br />
...<br />
Exp.<br />
...<br />
0*002<br />
...<br />
...<br />
Difference.<br />
Cont.<br />
0-008<br />
0*007<br />
O-005<br />
O-002<br />
...<br />
It may be assumed that the volume remains constant, the differences<br />
between the specific gravities found and calculated being negligible.<br />
Remarks on the Preparation of Useful Alloys.—In working<br />
with antimony alloys it is important to cast them at a temperature<br />
as low as possible, and to pour into cold moulds, so as to aid rapid<br />
solidification and obtain a fairly uniform mass instead of an eutectic<br />
alloy. Brass moulds must be used for casting, and must be coated<br />
on the interior with a mixture of lamp-black and oil of turpentine,<br />
or lamp-black alone, to prevent any adhesion of the alloy to the mould.<br />
Red chalk mixed to a uniform mass with water can also be used.<br />
The mixture for an alloy must be thoroughly stirred. If the alloy
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