1890-91.] NOTES ON NICKEL. 87 



gradually cooled off the more difficultly fusible Iron Sulphide would 

 harden first, leaving a spongy mass, while the Nickel Sulphide, still re- 

 maining liquid, would seek the lower levels. The next operation, smelt- 

 ing the roasted ore, generally takes place in a shaft furnace, not high, 

 on account of the formation of Iron bears, which takes place when the 

 ore is exposed long to a reducing action. The great difficulty of this 

 smelting is the formation of bears in the furnace, so that the furnace can 

 not run more than about three weeks. These bears are extremely tough 

 and must be sometimes broken by dynamite. Recent improvements 

 have, however, greatly reduced this difficulty. (Sudbury). 



The next operation, the roasting of the matte, can be done in heaps or 

 a reverberatory furnace. The smelting of the roasted matte can be per- 

 formed either in shaft or reverberatory furnaces. Quartz and limestone 

 must be added here in order to slag the Ferrous Oxide in an easily 

 fusible, double Silicate. We have now to do with a mixture of Fe S, Ni 

 S, Cuo S, with metals dissolved in them, which is proved by the fact 

 that on cooling, crystals of a metallic appearance separate out, which, 

 on being analysed, shew their metallic nature. 



The next operation, blowing the concentrated matte, can be per- 

 formed on a small refining hearth, like a Copper hearth. The hearth is 

 first warmed with charcoal, then filled with coke, and when the coke is 

 burning well, it is charged with the concentrated matte in large pieces. 

 This soon melts and collects under the coke. The blast is now let play on 

 the surface of the molten metal, the Iron thereby oxydized, and forms in 

 connection with the material forming the hearth and coke, a slag which 

 flows off regularly. The smelter can tell the end of the process by 

 observing whether the fresh fracture of a test piece possesses a light gray 

 colour. The coke is then taken off and the blast continued till the mass 

 has hardened. 



The composition of this product had in one works (Ringer) — 



29.79 Copper, 

 40.45 Nickel, 



6.1 Iron, 

 22.27 Sulphur. 



In Lyons, the raw matte is treated in a Bessemer converter till the 

 Iron is nearly all gone. Thus out of a raw matte containing — 



6.0 Nickel, 

 2.0 Cobalt, 

 0.75 Copper, 

 38.25 Iron, 



