Some Electrical Supply Aspects of Ferro-Alloy Manufacture

Before discussing the electricity supply aspects of ferro-alloy manufacture, the principal ferro-alloys, the method of grading and their uses are summarized and representative electricity consumptions per ton of finished alloy are given. In order to indicate the magnitude of the load, statistical information regarding the quantity of electrically manufactured ferro-alloys is next given over a period of years. This is followed by a description of the type of furnace used, together with brief notes on the electrical equipment and details of the electrodes. In order to indicate the importance of electricity costs the selling price of typical ferro-alloys is given and, for comparison, the proportion of the selling price that each tenth of a penny per kWh represents. It is also pointed out that supplies of raw material are as easily available in Great Britain as they are in the major ferro alloy producing countries, viz. Norway, Sweden, and the U.S.A. In order to establish the price at which electricity can be made available, typical costs of production for a 50 000-kW steam station are given and, on 1939 costs, aprice of ¿d. per unit arrived at. At the same time, comparison is drawn with hydroelectric power and it is shown that for equality of production costs, all other things being equal, the capital expenditure in a hydro-electric station could be as high as £72 per kW installed. The disadvantages of a number of private generating stations are obvious and it is shown that an electricity supply obtained from the Grid is more advantageous. Finally, some typical costs of production for ferro-alloys are given.