594 
MANGA>rESE DEPOSITS OF INDIA: ECONOmcS. [pART III : 
In addition to spiegeleisen and ferro -manganese there is a large 
number of other alloys containing manganese.i 
Other manganese alloys; . ■ ^ ^- \ <■ n " • • 
An mterestmg account or the alloys contammg 
manganese is given by Penrose in his book on manganese, and 
to this reference may be made. Since this was written, however, much 
work has been done on alloys containing manganese. Attention may be 
drawn to Heusler's magnetic alloy of copper, manganese, and aluminiums, 
and to Guillet's work on nickel-manganese steels.^ The only alloys 
that can be mentioned here in addition to those abeady noticed are 
silicon- Spiegel and manganese -bronze. 
For some purposes alloys of iron rich in both manganese and silicon 
are required. Such allovs are known as silicon- 
Silicon-spiegel. • 7 i w • / ' < 1 
Spiegel &rva sikcon-ferro.manganese. An example 
of silicon-spiegel is an alloy containing 10% silicon and 20% manga, 
nese. The name manganese-bronze is applied to alloys of manganese 
and copper, sometimes with iron as well. In 
-Mansaneise-bionze. ,, , i r , i 
commerce there are now two grades 01 metal. 
One is a mixture used for rolling into sheet, or drawing into wire or 
tubes, and also for forging. It contains no aluminium and cannot be 
cast in sand. The other grade contains aluminium, and is suitable for 
sand-casting, being largely used for the manufacture of ship's propellers. 
Both these grades apparently also contain zinc.4 Manganese-bronze is 
distinguished by a remarkable strength, toughness, and hardness, and 
by a non-liability to corrosion by sea-water ; hence its use for propellers. 
Metallic manganese also is now manufactured on a commercial scale, 
namelv at Essen in Germany, the Goldschmidt 
Metallic- manganese. process of reduction by aluminium being used. 
Owing to its high cost as compared with ferro -manganese (about 10 to 1 ) 
its use is limited mainly to the manufacture of copper and other special 
alloys 5. The price is quoted in the Engineering and Mining Journal 
for January 25th, 1908, page 239, as 75 cents per lb., at New York, 
for metal containing 98-99 % Mn. 
1 In the Iron ond Coal Trades Review, June 29th, 1906, pp. 2316, 2317, there i.': an 
interesting article entitled ' Some Use« ol Pure Manganese and its Alloys.' 
2 Eng. Milling Journal, 13th Jan. 1906, p. 84 : B. V. Hill, Electrician, Nov. 24, 1905 ; 
A. D. Ross, Proc. Roy. Soc. Edin., XXVII, pp. 88-92, (1907). 
'i Revue de 31etaUurgic, Nov. 1005. Ahstraot in Iron avd Steel Mag., XI, April 1906, 
p. 329. 
4 Eng. Minimj Jour., 8th Sept. 1906, p. 458. 
6 ' Mineral Industry '. X, p. 441, (1901). 
