SMELTING ORES BY ELECTRICITY 



States produced 86%. It is also known that the value of 

 American electrolytic refineries has doubled in the last six 

 years, although the exact figures are not available. 



The second in importance, no doubt, is the production 

 of aluminum. Tins has been a staple article for a number 



of years. 



i\nother extensive use of the electric furnace is in the 

 manufacture of calcium carbide. This, through contact 

 with Waaler, gives off acytelene gas, and the rapid develop- 

 ment of acytelene gas hghting is largely due to the grow^th 

 of the calcium carbide industry. 



The carbide is produced by heating together in the 

 electric furnace a mixture of 65% lime with 35% carbon or 

 coke. This is being carried on in a large scale at the 

 Shawinigan Falls Carbide Co., near Montreal. 



The to-day widely used abrasive carborundum was 

 discovered by K. J. Acheson, of the Acheson Graphite Co., 

 Niagara Falls, Ont., while conducting .some experiments 

 in the production of aluminum, wdiich he developed through 

 later highly successful experiments. It had been noticed 

 that in the case of overheating of the carborundum fur- 

 naces, that some of the crystals next to the heating core, 

 and w^hich were subjected to the highest temperatures, 

 were entirely converted into graphite. This suggested the 

 method, which as now followed, results in the production 

 of pure graphite^ having only a fraction of one per cent, of 

 ash. 



