Show ELECTRIC FURNACES IN IRON INDUSTRY the investigations that the U S bureau of mines is making into the metallurgical industries the application of electricity to various processes and especially in the manufacture of iron and steel is given attention in bulletin 07 67 electric furnaces for making iron and steel just issued by the bureau the investigations into electric furnaces for making iron were made by dorsey A lyon and electric furnaces for making steel by robert M keeney the bulletin gives a historical review of the development of electric furnaces for making iron and steel and discusses the problems which remain to be solved in the use of electric furnaces for the smelting smelling sm elting of iron ores and the production of pig iron at a profit on a commercial scale mr lyon in discussing the electric furnace for the making of iron states that the electric furnace was not developed as a competitor of the blast furnace but for the purpose of finding a furnace and a process that would be able to produce iron in those localities cali ties where blast furnace practice was not feasible or where the increasing cost of suitable fuel was becoming prohibit prohibitive ve to the existing practice of smelting smelling sm elting in blast furnaces broadly speaking he declared it may be stated that the feasibility of smelting smelling sm elting iron ores in an electric furnace depends upon the relative cost of either charcoal or coke and of electric power As regards the latter it must be cheap in those electric furnace iron plants that are operating at the present time only hydroelectric power is used the cost of producing power for electric furnace work must of course vary with local conditions and hence depends upon the initial cost per kilowatt of installation in general there are few localities where the electric smelting smelling sm elting of iron ores would be f feasible with the electrical energy costing more than 20 to 30 per kilowatt hour the second part of the report presents a brief historical review of the development of the electric furnace in the manufacture of steel up to the present time mr keeney describes in detail the types of electric furnaces in commercial operation for the manufacture of steel and in gen eral types which have not yet attained wide use he gives a description of the practice of the european and american electric furnace steel plants and compares in a general way the different types of furnaces and the more established methods of steel manufacture with the electric furnace process mr keeney states that the cost of making steel in the electric furn furnace ac e varies with local conditions the cost of power does not enter anter so largely into the final cost as it does in some other lurg ical processes especially the refining of molten steel plants are operating successfully cess fully under a power cost of one cent per kilowatt hour in localities where material can be obtained at the price common to other processes plants such as the one at ugine france have been established in remote localities where the cost of power is very low 02 cent per kilowatt hour but the cost of material is high for many years all high grade steels were manufactured by the crucible process but since the advent of the electric furnace there has been a gradual adoption of that furnace for refining steel for the complete refining of the highest grades of steel the use of the electric furnace is now thoroughly established in europe any product that can be made by the crucible process can be made by the electric furnace and in most cases with cheaper raw materials and at a lower cost in the electric furnace complex alloy steels can be made with precision the high temperatures attainable facilitate the reactions and alloys need not be used so largely for the purpose of removing gas very low carbon steels can be kept fluid at the high temperatures pera tures steels free from impurities and of great value for electrical apparatus can be made with the electric furnace large castings can be made from one furnace whereas in the crucible cra cible process steel from several crucibles cruci bles must be used for small castings which require a very high grade metal free from flags and oxides electrically tri cally refined steel is especially adapted the electric furnace gives a metal of low or high carbon content as desired hot enough to pour into thin molds and still free from flags and gases there is now a tendency among consumers of rail and structural steel to require a higher grade steel at an increased price rather than steel of acid bessemer hearth grade at a or even of basic open lower price with the high cost of power that now prevails throughout the steel centers of the united states the electric furnace cannot compete profitably with either the acid bessemer or the basic open hearth process in manufacturing steel of like grade from pig iron it is the combination with either of these processes that the electric furnace seems destined to be prominent in steel manufacture the cost of ing in the electric furnace the molten steel from either of these processes ex exclusive eldive of the cost of the molten steel varies from to per ton depending on the cost of power and the impurities to be removed |