Abstract: An arc furnace electrode control includes phase angle measuring devices connected respectively for producing a phase angle signal functionally related to the phase angle between the primary electrode voltage and current. A bias circuit is coupled to the primary of each phase for producing a bias signal functionally related to the reactive volt amperes delivered to the electrodes. Null detectors are coupled to each phase angle measuring device for receiving one of the phase angle signals and to the bias circuit for receiving the bias signal for producing a control signal for each phase related to the difference between the respective phase angle signal and the bias signal. A control is coupled to each null detector and is responsive to each control signal for individually positioning the respective electrodes in relation to the furnace so as to achieve preselected phase angles.

Abstract: An iron free self baking electrode comprises an outer metallic shell, a center core formed of a graphite or prebaked carbon material spaced from the shell and a quantity of a carbonaceous paste which cures into a solid electrode and bonds to the graphite or prebaked carbon core as the core and paste passes downwardly through the casing. The graphite or prebaked carbon core conducts heat to the paste material to promote more rapid curing.

Abstract: A water-cooled arc furnace electrode includes a hollow metallic jacket having a cylindrical wall portion supported in spaced relation from a graphite electrode. A shell is spaced from and surrounds the wall portion and has a section extending below the wall portion and upwardly into engagement with the lower end thereof. A baffle is disposed between the wall portion and the shell to define a first cooling fluide passage for water flowed downwardly between the shell and the baffle and a second passage extending upwardly between the baffle and the wall portion. A plurality of spaced electrical contact members are mounted on the lower portion of the shell and are in pressure engagement with the electrode. The shell and the contacts provide a current path around a proportion of the electrode for increased conductivity and to minimize electrode oxidation.

Abstract: Low grade ores, such as low-grade manganese ore, are reduced in an electric smelting furnace having two melting zones divided by a barrier. The ore and a small quantity of carbon are melted in the first zone at a temperature sufficient to reduce the iron oxide contained in the ore to molten iron, leaving molten layers of ore and slag which are richer in manganese than the starting material. The melt and slag are allowed to flow over the barrier to the second zone where a second charge of ore and a greater amount of carbon are deposited. Electrode melting in the second zone is carried out at a higher temperature to reduce the manganese and remaining iron therein to form a high-grade ferromanganese product. The molten products are tapped from the furnace in the respective zones. The method of the present invention may be used with other ores such as low grade chromium ore and the method may also be used for the production of silicomanganese.

Abstract: A method of producing aluminum is carried out in an electric arc furnace having primary and secondary zones separated by a divider constructed to permit the flow of molten but not gaseous products between zones. The method includes providing a charge of carbon into the primary zone containing a mixture of aluminum and aluminum carbide and providing a charge of alumina to the secondary zone, simultaneously heating the zones to react said carbon with the aluminum to form aluminum carbide in said mixture, flowing the mixture into the secondary zone, reacting the aluminum carbide in the mixture with alumina to form additional aluminum and an aluminum oxycarbide slag, flowing the slag to the primary zone for reaction with the aluminum carbide to form aluminum in the mixture, and tapping aluminum from the secondary zone.

Abstract: A method of producing aluminum is carried out in an electric arc furnace having primary and secondary zones separated by a divider constructed to permit the flow of molten but not gaseous products between zones. The method includes providing a charge of carbon into the primary zone containing a mixture of aluminum and aluminum carbide and providing a charge of alumina to the secondary zone, simultaneously heating the zones to react said carbon with the aluminum to form aluminum carbide in said mixture, flowing the mixture into the secondary zone, reacting the aluminum carbide in the mixture with alumina to form additional aluminum and an aluminum oxycarbide slag, flowing the slag to the primary zone for reaction with the aluminum carbide to form aluminum in the mixture, and tapping aluminum from the secondary zone.

Abstract: A method of smelting lead comprises the steps of containing a quantity of crude lead in an electric arc furnace, disposing a layer of coke or carbon granules over said lead, disposing at least two spaced apart electrodes in contact with said granules, energizing said electrodes for passing an electric current through said granules for heating said lead to at least its fusion temperature, and withdrawing the molten lead from beneath the granules.

Abstract: An electrode contact assembly includes spaced-apart U-shaped hollow tubular members each having a contact shoe affixed to each leg. A pressure ring surrounds the contact shoes for forcing the same into pressure engagement with the surface of an electrode. The tubular members are adapted for connection to sources of electrical energy and cooling fluid. A support ring concentric with the electrode and spaced above the pressure ring independently supports the pressure ring and the tubular members.

Abstract: Ore taken from the group consisting of low-grade manganese ore ferromanganese ore and chromium ore is reduced in an electric arc furnace having two melting zones divided by a barrier. Ore and a small quantity of carbon are melted in the first zone and ore and a larger proportion of carbon are melted in the second zone. The molten metal product in the first zone forms a pool below a molten layer of slag having a high content of metal above which is disposed unmelted ore and carbon. The slag layer is flowed over the barrier to the second zone for enriching a second charge of ore and carbon therein. Depending upon the type of ore being reduced, a first molten product such as iron or high-grade ferromanganese is tapped from the first zone and a second molten product such as high-grade ferromanganese, high-grade ferrochromium or silicomanganese is tapped from the second zone. The barrier may be formed of carbon covered by a surface layer of titanium carbide.

Abstract: Tricalcium silicate materials useful in the production of Portland and other cements are prepared by melting a mixture of materials comprising basically line and silica in an electric furnace. The voltage between the electrodes and the conductivity of the melt are controlled so that a predetermined separation will be maintained between the lower end of the carbon electrode and the melt.

Abstract: A method is disclosed for obtaining useful products from cement kiln waste dust. The dust is collected and added to an electric arc furnace where it is melted. The temperatures required to melt the dust are sufficiently high that alkali sulfates present in the dust are volatilized, leaving a melt which has a composition acceptable for the production of cement clinker. The volatilized components are collected to form a second useful product; i.e., a potassium rich material suitable for the production of potassium bearing chemicals, such as fertilizers.

Abstract: Bus bars for connecting arc furnance electrodes to a transformer include pairs of flat, rectangular, hollow, conductive members having side surfaces substantially greater in length than the end surfaces. One side surfaces of the bus bar of each pair are disposed in a parallel, closely proximate relation with respect to the other and a sheet of insulating material disposed between said surfaces. The bus bars of each pair are connected to transformer terminals having different polarities. The bus bar pairs are arranged in a closely spaced parallel relation.