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: 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 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: 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 vacuum degassing apparatus has first and second degassing vessels each separately mounted for independent horizontal movement from a first operative position to a second repair position. In addition, each vessel is independently mounted for vertical movement in each position so that a pair of nozzles extending from its lower end to be immersed into a ladle of hot metal when the vessel is at its operative position whereby a degassing operation may be performed. Also, when the vessel is in its repair position, it may be lowered to permit repair or replacement of the nozzles or the vessel bottom as may be required. A vacuum conduit is pivotally connected to each vessel and to a fixed vacuum conduit to maintain the vacuum connection while the vessel is being moved into and out of its various positions.

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 positioning control for electric arc furnaces includes a first circuit for producing an electric error signal functionally related in magnitude and sense to the electrical parameters in the electrode. The error signal is used to control the firing angle of an electronic switching device coupled between an electrode positioning motor and its power source. In addition, a signal generator is coupled to the motor for providing a velocity feedback signal functionally related to motor speed and direction for further modulating the firing angle.

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: An arc furnace electrode is suspended by means of a clamp assembly which includes contact shoes adapted to bear against the surface of the electrode. The contact shoes are pivotally mounted adjacent their upper ends and force producing means independent of the shoe support engages each contact shoe for forcing the same into high pressure engagement with the electrode.

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.

Abstract: An electric arc furnace has a plurality of electrodes each supported at one end of an arm, the other ends of which are each coupled to a column supported for vertical movement by means of a cable assembly. A fail-safe assembly is mounted adjacent the column and is coupled to the cable assembly. While tension is maintained in the support cable a linkage assembly normally restrains a biasing spring from moving a clamping wedge into engagement with the column to prevent vertical movement thereof. When tension is lost in the cable assembly the biasing spring is released to move the wedge into engagement with the column.

Abstract: An electric arc furnace has a body mounted on a pivotable platform and electrodes which extend through a furnace cover. A gantry supports the cover and electrode and is mounted on a rail for swinging movement onto and off of the platform to move the cover and electrodes from above the furnace body to a remote position. A pair of support columns are mounted below the edge of the platform over which the gantry moves and each column is pivotal into and out of a vertical supporting position to permit the platform to pivot. Shock absorbers limit pivotal movement of the platform in each direction and cushion engagement between the platform and the columns.

Abstract: A refractory lined electric arc furnace has a hearth, sidewalls and an arched roof. Skewback refractories are disposed between the roof and the sidewalls and are pivotally coupled to vertical support posts which bear against the sidewalls so that the skewbacks may change their angular relation to the sidewalls without inducing undue stresses in the roof as the lower ends of the side walls move inwardly and outwardly as the result of unequal expansion of the hearth relative to the roof.

Abstract: An electric furnace electrode coupler comprises a power driven chain loop which wraps tightly around a new electrode section such that when the belt is translated the new section is turned and screwed onto an operating old electrode section. Means are provided for tensioning the chain for gripping. The drive mechanism for the chain is mounted on an extensible and swingable arm for enabling operation on several electrodes associated with one furnace.