SMELTING ORES BV ELECTRICrTY 



square x 55" long. The consumption of the electrodes is 

 usually slight on account of the low current density. The 

 cost of electrodes per ton of product in this furnace is 

 approximately .77 cents. It is believed that charcoal or 

 peat-coke could be successfully used in this furnace as the 

 reducing agent. 



The electrical conditions in this furnace when smelting 

 under normal conditions are approximately as follows : — 

 Mean voltage 70 volts. 

 Mean current 9900 amperes. 

 Power factor about 74% . 

 Mean K.P. 51.3. 



The low power factor is accounted for by the iron 

 casing which forms a continuous magnetic circuit around 

 each shaft of the furnace, and which is highly magnetized 

 by the heavy current, giving to the circuit a very high 

 resistance. 



In this type of furnace the energy absorbed per ton of 

 pig was found to be .475 E.H.P. years for the run with 

 furnace of 1,000 H.P. capacity with mean current of 11,000 

 amperes at 60 volts, and .226 E. H. P. years for the run 

 with furnace of 308 H.P. capacity with mean current of 

 7,000 amperes at 55 volts — giving an average of .350 E. 

 H.P. years. The cost of producing one ton of pig by the 

 Keller process is estimated at $12.05, assuming electrical 

 energy at $10 per H.P. year and coke $7 per ton. This 

 cost might have been reduced if some means were devised 

 to utilize the Carbon-Monoxide CO. which was wasted. 



The Heroult process for steel making permits the 

 purification of material used, and different grades of steel 

 can be made without difficulty. 



The furnace for this process is of the tilting pattern. 

 It consists of an iron casing lined with dolomite brick, and 

 having magnesite brick around the openings. The hearth 

 is formed of crushed dolomite, carefully rammed on top of 

 the dolomite lining of the bottom of the iron casing. Two 



