Electric furnace sentence example
A somewhat impure silicon (containing 90-98% of the element) is made by the Carborundum Company of Niagara Falls (United States Patents 745 122 and 842273, 1908) by heating coke and sand in an electric furnace.
But in some cases in which the current is used for electrolysis and for the production of extremely high temperatures, for which the calorific intensity of ordinary fuel is insufficient, the electric furnace is employed with advantage.
The electric furnace has several advantages as compared with some of the ordinary types of furnace, arising from the fact that the heat is generated from within the mass of material operated upon, and (unlike the blastfurnace, which presents the same advantage) without a large volume of gaseous products of combustion and atmospheric nitrogen being passed through it.
This advantage is especially observed in some cases in which the charge of the furnace is liable to attack the containing vessel at high temperatures, as it is often possible to maintain the outer walls of the electric furnace relatively cool, and even to keep them lined with a protecting crust of unfused charge.
There is, however, one (not insuperable) drawback in the use of the electric furnace for the smelting of pure metals.Advertisement
Later in that year they patented a process for the reduction of aluminium by carbon, and in 1886 an electric furnace with sliding carbon rods passed through the end walls to the centre of a rectangular furnace.
Moissan (ibid., 5906, 142, p. 673) has distilled this metal in a very intense electric furnace.
TiN 2 is a dark blue powder obtained when the oxide is ignited in an atmosphere of ammonia; while TiN is obtained as a bronze yellow mass as hard as the diamond by heating the oxide in an atmosphere of nitrogen in the electric furnace.
Strontium carbide, SrC2, is obtained by heating strontium carbonate with carbon in the electric furnace.
Moissan obtained a carbon-bearing metal by fusing the pentoxide with carbon in the electric furnace.Advertisement
At a red heat it absorbs large volumes of hydrogen and nitrogen, the last traces of which can only be removed by fusion in the electric furnace.
Pure crystalline calcium carbide yields 5.8 cubic feet of acetylene per pound at ordinary temperatures, but the carbide as sold commercially, being a mixture of the pure crystalline material with the crust which in the electric furnace surrounds the ingot, yields at the best 5 cubic feet of gas per pound under proper conditions of generation.
Mourlot has shown that aluminium sulphide, zinc sulphide and cadmium sulphide are the only sulphur compounds which can resist the heat of the electric furnace without decomposition or volatilization, and of these aluminium sulphide is the only one which is decomposed by water with the evolution of sulphuretted hydrogen.
The carbide, SmC2, is formed when the oxide is heated with carbon in the electric furnace.
It can be distilled in the electric furnace.Advertisement
It is more conveniently prepared by heating the oxide with carbon in the electric furnace.
It is now manufactured by heating lime and carbon in the electric furnace (see Acetylene).
In graphitizing en masse large lumps of anthracite are treated in the electric furnace.
Ostwald (ibid., 1900, 35, pp. 33, 204) has observed that on dissolving chromium in dilute acids, the rate of solution as measured by the evolution of gas is not continuous but periodic. It is largely made as ferro-chrome, an alloy containing about 60-70% of chromium, by reducing chromite in the electric furnace or by aluminium.
Gases, like atmospheric air, hydrogen or carbon dioxide do not become luminous if they are placed in tubes, even when heated up far beyond white heat as in the electric furnace.Advertisement
In connexion with these experiments he developed the electric furnace as a convenient means of obtaining very high temperatures in the laboratory; and by its aid he prepared many new compounds, especially carbides, silicides and borides, and melted and volatilized substances which had previously been regarded as infusible.
There are two distinct ways of making the steel objects actually used in the arts, such as rails, gear wheels, guns, beams, &c., out of the molten steel made by the Bessemer, open hearth, or crucible process, or in an electric furnace.
The carbide BeC 2 is formed when beryllia and sugar charcoal are heated together in the electric furnace.
Siemens on the electric furnace was continued and greatly extended by Henri Moissan and others on its scientific side, and electro-chemistry took its place as one of the most promising departments of technical research and invention.
Moissan (Comptes rendus, 1896, 122, p. 1297) obtained a vanadium containing from Io to 16% of carbon by fusing vanadic anhydride with carbon in the electric furnace.Advertisement
Moissan (Coniptes rendus, 1896, 122, p. 1297) by heating vanadium pentoxide and carbon for a few minutes in the electric furnace.
In this article the general principles of metallurgical furnaces will be treated; the subject of gasand oil-heated furnaces is treated in the article Fuel, and of the electric furnace in the article Electrometallurgy.
The electric furnace has led to the discovery of several important materials, which have been employed as furnace linings.
Moissan and P. Williams (Comptes rendus, 1897, 12 3, p. 6 33) by reducing the borate with aluminium in the electric furnace.
Heated in the electric furnace in a current of air, it yields calcium cyanamide (see Cyanamide).