SMELTING ORES BY ELECTRICITY 



rotated while in operation to produce proper intermixture 

 of the melting mass, and in this way the heat is used to 

 better advantage. It is also claimed that the lining lasts 

 longer as a result of the movement. The furnace is of the 

 arc type, consisting of a cylindrical outer casing of iron 

 mounted on a conical roof. The axis of the furnace while 

 rotating makes an angle of 70° with the vertical. Three 

 electrodes project inward toward the centre of the furnace, 

 and they are connected to a three=phase supply circuit from 

 which they draw 400 amperes at about 90 volts per phase. 

 The distance between the electrodes is controlled by a 

 hydraulic regulator. 



This type of furnace has been used up to 1,000 H.P. 

 capacity with an output of four to five tons per day. Four 

 electrodes were used and supplied from a two-phase alter- 

 nator, each arc consuming 2,450 amperes at 150 volts. The 

 electrodes are round, two inches in diameter, by four to five 

 inches long. The lining lasts under ordinary circumstances, 

 and some trifling repairs, for about 40 days. 



A report of the results of tests made by the Canadian 

 Commission upon various processes in operation in Europe 

 is given below : 



