1890-91.] NOTES ON NICKEL. 89 



■cubes the Nickel Oxide is formed into cakes, then ignited with coal dust. 

 The ignition takes place also in crucibles. 



Care must be taken not to let the Nickel, after the reduction, remain 

 long in contact with coal, otherwise Carbon will be taken up and the 

 physical properties of the Nickel thereby deteriorate. 



As Nickel is almost always alloyed with Copper, an alloy can be made 

 direct from the concentrated Matte, by treating it in a Bessemer Con- 

 verter till only traces of Iron and Sulphur remain. 



Thus, here is a Matte and the resulting alloy — 



The direct process by electrolysis was at first not successful. The 

 Speisses and mattes containing Copper were hung as electrodes in a bath 

 of dilute Sulphuric Acid, and the Copper deposited on the negative 

 electrodes. The Nickel and Iron were allowed to collect in the bath till 

 the acid is nearly neutralized. A great part of the electrical is thereby 

 wasted on the generation of hydrogen, and the Copper is deposited 

 impure. An amount of Sulphuric Acid equivalent to the Nickel con- 

 tained in the positive electrode is used, which is lost in Nickel vitriol. 

 The iron is then precipitated by Ammonia, and the liquid is evaporated 

 down to produce pure Nickel Sulphate, or is electrolyzed to produce 

 Metallic Nickel. This process proved to be not economical. 



This process must be carried out analogous to the Copper deposition ; 

 that is, the Nickel and Iron must be dissolved out of the anode or posi- 

 tive electrode with the proper strength of current. The precipitation of 

 Iron on the negative electrode can be avoided by the alkaline nature of 

 the bath. Copper and Sulphur must remain in the anode and be treated 

 separately afterwards. 



The processes we have hitherto considered closely resemble the Copper 

 smelting processes ; but, when we come to the treatment of the Sili- 

 cates, a different picture is presented to us. Here we have to do more 

 with an Iron process. 



The New Caledonia ores, for instance, are smelted with coke in a 

 furnace about 25 feet high, under 12cm. mercury pressure of hot blast 

 The temperature of the blast is 400 ° C. Fluorspar, soda, manganese 

 ores, Iron ores, are added to the charge. Out of one ton of ore 



